I've touched on the beginnings of this project in a couple other threads, but I'll document the process from beginning to end here. Plans are mostly finalized, but could certainly change along the way. And, thanks to all who have blazed this path ahead of me...plenty of the decisions made so far were based on feedback found at this great site. Trust I'll not be shy about posing questions to the many experienced participants here as this project moves forward.
The rig: 2002 26.5 Mid Bath
I'll cover some of these in more detail as they are installed, but the basics:
- 3 x 200AH Lifeblue heated lithiums
- Victron 12/3000/120 Multiplus inverter/charger
- Victron solar charge controller (using existing installed panels)
- Cerbo GX w/Amazon fire tablet for wireless control/display
- Nations 280A Dual Alternator kit w/Wakespeed WS500 external regulator (https://www.nationsstarteralternator.com/Dual-Altenator-Kit-with-270XP-for-1997-2018-Ford-E-p/fmk4692v-1997-to-2018-e-series.htm)
Several of the components are being repurposed from a Transit van recently sold, and as luck would have it they appear to be a perfect match for the LD midbath layout and our known needs. Specifically, the older Multiplus inverter will fit nicely in the space freed up by the original battery box removal, and the long, narrow Lifeblue 200's are a perfect fit for the compartment below the battery box. The length of these batteries is literally the exact depth of that compartment floor.
This is my fourth Victron/lithium installation, having worked with AM Solar on the previous three when they were still in business. They did all of one installation, the solar on another and only provided parts for the third. Still, even though I have one complete installation under my belt - this is my first motorhome installation so there are a few new bits to research and understand. And, I'll no longer have the safety blanket of AM Solar now that they are out of business. They sure proved their worth on previous installations, providing valuable info and advice as I worked my way through those projects.
Charging of the bank via a secondary alternator is new to me, as is incorporating the Onan generator into the mix. That last bit, though - my hope is, to never need the Onan again. I'll keep it in the mix for now, but after a year or so if we find it is never needed - it will be removed. What, if anything will take its place I'm not sure...but the one thing I've found limits our extended boondocking more than anything is water. Perhaps an auxiliary tank will go in its place, but that's a decision and project for the future.
Let the fun begin.
Location, location, location...it's not just for real estate.
Having done my last Victron/lithium installation in a van, my appreciation for squeezing things into tight spaces is fresh in my mind. Still, storage space will be lost. We read posts here about potential locations in the mid-baths, then analyzed our space preferences based on how we used our last two LD's. In short, it boiled down to whether we preferred giving up internal or external storage - and external got the axe. Batteries will go in the compartment below the original battery box and the bulk of new components will go where the original battery box was. Both the drawer and cabinet space beneath the fridge will remain 100% usable.
Here's the gutted battery box location, looking through to the storage space below the fridge. Space is actually gained removing the battery box, as there was a small amount of unusable space above and to the sides of the battery box.
(https://lh3.googleusercontent.com/pw/AP1GczPISeotWFMX2LusRocOfn5pYiz_G3lV0K_WyCQlikhOAZ4pGV7eSjjYx19ckuYyg9IE34OrIv-mPIMZL76ehn0GILEyiLVdbXhu_trh8HEBENnREqHC=w800)
And yes...still plenty of wiring cleanup and identification to do.
Here's a picture of the planned location for the largest component (other than batteries), the Multiplus inverter/charger. I'll be building a simple support frame out of 80/20 to hang it from, it will sit just high enough in this location to allow the 4/0 wires to exit. The 80/20 frame will also support the back of the drawer mount shown in the picture, as well as a mounting board for various other components accessible through the original battery door. Having monitored temps in the previous three installations, I believe there will be adequate airflow around everything once installed, but if not - it's trivial to wire up a couple fans in this location, triggering them off the Cerbo GX relays as needed.
(https://lh3.googleusercontent.com/pw/AP1GczNT8oV5q2y_piMDZB8YZvN3LbS-7YzokmA7fHjQNd-aVwDH7ooo6mPpIxBAglpCa8ae91ebG1cq2CxP1XJqGBijsgEF_Vbft3vfQSjtItV_Jhdyp_-u=w800)
Lastly, the lithium location with 3x200AH Lifeblues in place. As mentioned previously, these fit like a glove. There's actually enough room to put in a fourth battery for a total of 800AH, and I do have one more. However, that would require opening up a large hole in the floor above this compartment so batteries could be dropped in from above. As it is now, the batteries need to be slid into the lower compartment on edge, as they are too tall to go in upright. Even though the footprint of the compartment could hold a fourth battery, it's not possible to slide a fourth one in on edge then turn it upright through the small door.
(https://lh3.googleusercontent.com/pw/AP1GczNHgyebsMA4QK-LgCTGEssf-K18_7WxNKy_oxmmG-VxP5jAuqbUxg2QJkSaLSSDj1UK7EdDXNcitXEUjhcaBak_TQpoifMYeuMoWIqsXqWJ2e0TOPOV=w800)
Interesting. Removing the battery box really gives you a lot of space for components. What is the cable path from the old battery compartment to the compartment below?
What is the cable path from the old battery compartment to the compartment below?
A hole will need to be drilled between the two to pass two 4/0 cables. Doesn't look to be a big deal, I can see what I'm in for looking at the existing hole that the water tank drain pipe drops through.
I've yet to decide whether I'll put the main 400A battery bank fuse and disconnect switch in the lower cabinet with the batteries, or up above with the inverter and other components. The fuse should be as close as possible to the battery bank, but we're only talking an additional 8-10" if I put it up by the inverter. I'll see how it lays out and decide.
Removing the battery box can be a PIA and worth the effort in an MB. It provides a lot more room.
Have you considered how hot the batteries may get in the lower compartment? Lithium batteries automatic shut off when they exceed 135 degrees. You may want to provide ventilation for summer usage..
When traveling in the summer heat, our lower compartments get very hot after hours on the road from the exhaust heat and heat radiating off the pavement. Most owners locate the lithium batteries in the interior, away from the heat and cold
4/0 cable is hard to bend, using flexible welding cable makes the project a bit easier.
Larry
A hole will need to be drilled between the two to pass two 4/0 cables. Doesn't look to be a big deal
I drilled mine in the forward corner of the battery box compartment when I added a 4th battery. Like you said, no big deal.
whether I'll put the main 400A battery bank fuse and disconnect switch in the lower cabinet
I put mine in the upper one. Easier to access than the lower one.
Really enjoy the high res photos.
jor
Today was mostly more layout planning, and I think I've ID'ed all cables. However, the highlight of my day was an "aha moment"...
It's really been bugging me I couldn't fit the fourth 200AH Lifeblue in the lower compartment. Not only because the space is perfect for four of them, but all four were in the van install these components were removed from. I know the capacity will easily handle a week of our needs (regardless of solar), but also - the previous installation took this capacity into mind with sizing of components and Victron programming.
I mentioned it earlier, but the batteries have to be slid in on their side then turned upright due to the compartment height...and there wasn't enough room to turn the fourth one upright.While staring at the compartment, it occurred to me I could slide a battery all the way aft in the compartment if the the water tank drain pipe wasn't there...and of course, it's just screwed into the valve. Removed the lower pipe section below the valve, slid a battery all the way over in its place, and that gave enough room to slide the fourth one in and turn it upright. Slid the battery back over and reinstalled the pipe. Bingo!
80/20 framing is up next.
(https://lh3.googleusercontent.com/pw/AP1GczOJ5uRJzQkP8R5fUUaGlG3bddd4n0v2JKcpiOEcjjgpCNh9EPjfgjj2aAsG7_OPvXSHCZq-duBt9sxRS8BLtk-Ag7OFPZE8buUzjktOy1ewi7dSBBUh=w800)
Have you considered how hot the batteries may get in the lower compartment? Lithium batteries automatic shut off when they exceed 135 degrees. You may want to provide ventilation for summer usage..
I'd not thought of that, Larry - thanks for the heads up. All of my other installs have had the lithiums inside and temps were not a problem.
I looked up the BMS specs on the Lifeblues, and they cut off at 149 degrees. Still, cooler is always better. I've seen articles about using temperature probes and the relays on the Victron Cerbo GX to trigger fans - I'll look into that, along with providing ventilation between the lower and upper compartments.
4/0 cable is hard to bend, using flexible welding cable makes the project a bit easier.
I've a bunch of 4/0 cable from the van install, and all the cables are longer than needed so cutting and putting new ends on will save quite a bit of $$. They are Ancor - marine grade, tinned and a super high conductor count. They are almost as flexible as welding cable, but I think the only place that's going to be an issue in this installation is coming out the bottom of the Multiplus. I've already tested one of them to see what kind of radius is needed, and the Multiplus will sit high enough to easily accommodate it. All the other house component runs are less than 12" and relatively straight.
I'll look into welding cable for the secondary alternator to bus bar connection, though. Flexibility will be key there, plenty of bends along the way.
When drilling through the floor, the holes are drilled oversize and then a piece of PVC pipe is glued in place, providing a neat passage for wires and cables.
(https://live.staticflickr.com/5652/21885786248_0afd48ca74_3k.jpg) (https://flic.kr/p/zkYnLd)
You might consider placing the batteries inside and mounting the inverter and other equipment below. Things should fit both ways.
Larry (https://flic.kr/p/zkYnLd)
Here are some items for the road heat on the batteries.
https://www.perplexity.ai/search/how-can-one-insulate-a-lithium-Y9UoP1fUTYy.0ADWDKah0A
Ron S
You might consider placing the batteries inside and mounting the inverter and other equipment below. Things should fit both ways.
There's not enough room under the fridge for the batteries I have - not even three of them, much less four. That is, unless I sacrificed all of the storage space below the fridge.
Andy Baird linked to these a while back (https://www.sunfunkits.com/product/51/sfk-300hp-12v-300ah-40-kwh-dual-heating-lithium-victron-communications-battery), and were I needing lithiums I'd seriously consider three of them for their features and form factor. However, while they
might fit in the old battery box area - that's nearly $3K for something I already own.
I think there's enough room in the lower compartment to line the bottom with foam insulation under the batteries, and perhaps some thinner insulation could be placed on the sides. I'll check into that as well.
There's not enough room under the fridge for the batteries I have - not even three of them, much less four. That is, unless I sacrificed all of the storage space below the fridge.
it would be a healthier environment for the batteries. The overall amount of storage does not change.
Larry
Four lithium batteries and associated cabling will weigh well in excess of 100 lbs. I’m curious if there is a recommended weight limit for those lower compartments?
Four lithium batteries and associated cabling will weigh well in excess of 100 lbs. I’m curious if there is a recommended weight limit for those lower compartments?
Actually, it's quite a bit more than that. Each 200AH Lifeblue is 58 lbs. There will be a fuse and several feet of 4/0 cable down there too, so probably just under 250 lbs. total.
I've never seen a published weight limit, but I do know we've carried about the same weight in both our previous 27 RB and 24 TK compartments when we owned them. A typical winter trip south had us dedicating a single lower compartment to 200 lbs. of dog food + several cases of water. Never had an issue. The boxes themselves are pretty substantial, but more importantly they are supported with some pretty stout steel straps. Still...I don't know the answer.
it would be a healthier environment for the batteries. The overall amount of storage does not change.
True regarding the environment, however the flip side is it would be far less healthy for all those expensive Victron components that would be installed down there. And, not only heat - but on previous LD's, I've seen condensation in the lower compartments. I would think batteries are far less impacted by that than inverters, solar charge controllers, the Wakespeed, Cerbo GX etc.
Lastly...I'm gonna pull the old man card. It's WAY more difficult to work in the lower compartment down on the ground, doing everything through its very short door. With batteries, they are in and done in minutes - hopefully never needing significant attention for 7-10 years. With all the components installed through the battery box door, I can sit on a stool and comfortably work on everything. ;D
Regarding the space, yes - available storage would be more or less equal regardless of location, however we don't want to give up any interior storage space. For us, that's in far shorter supply for our needs than external storage. For those who don't mind losing the space under the fridge, keeping the batteries in that location certainly has its benefits. And of course, many won't need/want the lithium capacity we're installing - so with 200-400AH of lithiums, all would likely fit in the area previously containing the battery box.
I've pretty much decided to do two things to address potential temp issues down below. I verified yesterday there's space on the bottom of the compartment for 2" rigid foam, so I'm going to look into adhering some of that to thin ply as a base for the battery bank. There's not as much room on the side walls or door, but I'll look into adhering something thinner there as well. More importantly though, I am going to design in ventilation controlled by the Cerbo GX. The thought is to cut two additional holes between the interior floor and the compartment, installing two fans - one pushing, one pulling. Triggering them with high and low temp thresholds via the Cerbo should keep the box temps roughly the same as the interior.
Keeping the batteries happy year-round may require a hybrid system.
If the batteries have Bluetooth, their temps can be monitored, if not, drop a remote temperature probe between two batteries to watch the temps.
For summertime use, adding vents to the exterior door, along with a fan should be better than pushing heat into the already warm interior. I have done this on previous installations. when a large inverter has been installed in the lower compartments..
For wintertime, closing off and insulating the exterior door and opening vents into the interior would help provide heat, possibly with a fan to encourage circulation. I assume the batteries have heaters to keep them warm in very cold conditions. If not equipped with heaters, 12-volt holding tank pads could be used to provide supplemental heat.
It is going to be hard to pump enough heat down into the exterior compartment in adequate quantities to make a significant difference.
To make working on the lower compartment easier, I have lifted the whole RV and placed it on four 12-ton jack stands.
Old bodies are a PIA.
Larry
While waiting on parts, I decided to tackle the solar wiring modifications I knew were needed. This coach had 3 x 100W panels and a BlueSky 3000i controller installed by AM Solar back in 2015. AM Solar having been one of the best, this is one part of my upgrade I expected little issue with. Sigh...the best laid plans.
AM Solar installed the BlueSky controller on the side of the cabinet above the sink, facing the doorway as you come in. A common place in the midbath no doubt, as the controller also has a display showing all aspects of the system.
(https://lh3.googleusercontent.com/pw/AP1GczMPFot3lWsH8fjiCBvXXH_92ERMIH-QAHquiUJdmIPTrBAv7Oet3NoQXc_xAW2S4B7RzDrIlv5FAv76_PHpgPPTvd3e58SXay1GNs7NLRcrOEVXDvbz=w800)
However, in the Victron world all display and control is typically handled in a single place, regardless of component. In my case, that will be a Cerbo GX connected wirelessly to an Amazon Fire tablet, a setup I recently installed in an Airstream that works beautifully. I'll fab up a mounting panel and place it where the BlueSky was to cover the hole. Anyway, the main point being - a LOT of solar wire runs in the AM Solar installation needed changing/removing.
Many of you are aware, but regardless of solar controller - a typical wire run is from the panels to a combiner box, then to the controller, then to the batteries. With the BlueSky installation where it was, this resulted in the following:
- 6/2 wire run from rooftop Combiner Box going through the fridge roof vent, then through the upper cabinets and to the Bluesky
- Another 6/2 wire run going from the BlueSky back along the same path through the cabinets/fridge vent, then back down the side of the fridge to the battery box.
My plan was seemingly simple. Remove the wire runs going to the BlueSky and repurpose the 6/2 cable running down the side of the fridge to feed the new Victron solar controller that will reside down there. So, yank some cable, cut the one running down the fridge vent and splice it back into the combiner box...maybe 20 minutes? Ha.
Removing the two 6/2 cable feeds to/from the BlueSky was easy, but when it came to the cut/splice in the combiner box - it disintegrated. The combiner box used back in 2015 by AM Solar literally fell apart upon opening it up.
(https://lh3.googleusercontent.com/pw/AP1GczMYc-QBLv528NP2bWp58haPGEL9dBT16_WtbeU4s_dB2N2I9FIjW-3lObm6R6ijopRFw_mSu7GiS7lhx4l61Sa7JJn-CF8MkFK7CctSkQeeXnehJLrU=w800)
I knew from an installation I did about a year back that AM Solar was selling a really nice rooftop combiner box of their own design, but with them out of business - I went on the hunt to find a quality replacement. I suspected AM Solar only designed the combiner box they were selling, and sure enough - I tracked down the company making it. I stumbled upon the Deployed Logic (DLX) Combiner Box (https://deployedlogix.com/power-logix/mobile-power/combiner-box/), and a quick call to their support confirmed it was the same box. The guy helping me actually worked at AM Solar.
With that ordered up, the wiring went off without a hitch. The box is super low profile, and in the likely event I add two more 100W panels - one will likely go right over the top of it. It installs with VHB tape, and I'll seal up the roof/box edges with a little Dicor.
(https://lh3.googleusercontent.com/pw/AP1GczMKH8Ve34zBImvRftCeqBE5UN99BuVcwojeNFYCoDXMy_TzquXcAFyZmZ-igXEM-OrzRHXEerbD4_2A4DqfbIeu7X3-NLOki678oiqATJV1WyXP8qUK=w800)
I knew from an installation I did about a year back that AM Solar was selling a really nice rooftop combiner box of their own design, but with them out of business - I went on the hunt to find a quality replacement. I suspected AM Solar only designed the combiner box they were selling, and sure enough - I tracked down the company making it. I stumbled upon the Deployed Logic (DLX) Combiner Box (https://deployedlogix.com/power-logix/mobile-power/combiner-box/), and a quick call to their support confirmed it was the same box. The guy helping me actually worked at AM Solar.
Was it James, who now runs Kindly Solar? We bought our combiner box and some AM Solar mounting brackets from him in 11/2024.
Was it James, who now runs Kindly Solar?
Sorry, don't recall the guy's name. I'm under the impression he's an employee of Deployed Logic as that's who I called.
Finished up the day with a pleasant surprise. I'd been looking into a hard-wired surge protector, and had pretty much decided to get the Progressive Industries EMS-HW30C. Turns out...the previous owner beat me to it! It's already there and already installed.
I've not traced all the wires yet, but I'm guessing it is wired in after the transfer switch to filter both shore power and generator. The Victron Multiplus needs to be added to the mix, and I'm double checking that now - but my guess is, it should go in after the EMS and before the AC circuits.
Hi Will. If you could share a picture of your surge protector install I would much appreciate it. I have the same unit and LD model and need to install it.
Hi Will. If you could share a picture of your surge protector install I would much appreciate it. I have the same unit and LD model and need to install it.
It's installed similarly to others I've seen posted here. Under the sink on the shared bathroom wall. Here's a view from behind the power center. Sorry for the blur.
(https://lh3.googleusercontent.com/pw/AP1GczPDYrpw5_r6ZDk59A0Xr9c0gOnN2ltSIYumqeS00mcHUrT0GfKveTeMrrEbGTYqexp8VtAX-YFroWrdtJy5BIGD2ZQB8dnO6hzDvM95xPmoYMIPotsH=w800)
Here are the connections to the power center. I'm assuming the input comes after the transfer switch, the output feeds the AC circuits - but I've yet to verify. The EMS cables are in the black sheathing. My plans are to splice the Multiplus AC lines into the output line of the EMS prior to it entering the power center.
(https://lh3.googleusercontent.com/pw/AP1GczOK4_HCJzoEul8TZzuGn11xdvsE1NdOOt4zuaW5xpiuYFWQHyjAha7q4vFqZzm59r4u0rqLK4w5yd4r9plITF_mNMEGtfRvkuk2p-RCD65AB3G_oyh-=w800)
As with other installations, the readout was attached to the wall above the power center - seen here.
(https://lh3.googleusercontent.com/pw/AP1GczOwQuAKwwDkZzpHOQld94zRYXFBYDv95IoGZGUOOF3IJDIgP_ZfcJ7lRvHLWhgXHsi0Uvi647PLeeLvOpfNzrxyl0Qy-n1gLsTKnlKj0y7msvQuRdjP=w800)
My plans are to splice the Multiplus AC lines into the output line of the EMS prior to it entering the power center.
Assume you mean taking the output of the EMS and running it through the Multiplus, utilizing the passthrough capability.
You don't want to splice the output of the EMS and the output of the Multiplus together and then feed the breaker panel.
Assume you mean taking the output of the EMS and running it through the Multiplus, utilizing the passthrough capability.
You don't want to splice the output of the EMS and the output of the Multiplus together and then feed the breaker panel.
I could have stated it more clearly, but I think we're on the same page?
How I think it currently goes:
Shore power/Generator --> Transfer switch --> EMS In --> EMS Out --> AC Panel in power center
How I think it should go with Multiplus:
...EMS Output --> Multiplus In --> Multiplus out --> AC Panel in power center
I could have stated it more clearly, but I think we're on the same page?
Yes :) When I read the original post with "splice", I thought you were considering wiring EMS output and Multiplus (as inverter power) output together (2 wires spliced to 1), and then running that to AC power in.
BTW, the most recent models of Progressive EMS (now owned by Navico) operate slightly differently than the original ones (as we discovered installing a new one in our coach.) It's something buyers need to be aware of, so I'll start a separate topic on that.
For those who have never used it, 80/20 is the bomb. And, given how many of you are of a certain era - you just might have erector set flashbacks. ;D
We could start a whole thread on tips and tricks with the material and usage, but the short version is - it's very light, super easy to work with and incredibly strong. Knowing the weight of Victron inverters, I knew it would be used to hang that heavy beast in my installation.
After gutting the battery compartment, I primed the OSB flooring underneath that extends to the storage beneath the fridge. Then, four 12x12 vinyl self-stick tiles went in place, requiring just a tiny amount of trimming. I didn't trust the self-stick goo on the bottom of them, so construction adhesive was used beneath, heat applied and a heavy roller sealed the new flooring down.
The frame is pretty basic, essentially dividing the ex-battery compartment and Victron component area from the under fridge storage area. It supports the drawer rail on the inside, the inverter and a component mounting board on the other side.
(https://lh3.googleusercontent.com/pw/AP1GczPaON8Dt3HDnNopr9VyOT-oiqyyKfKpgUQw_Ob4Vv8-B11UnJ1jqADjekp8tH_hNdDLqtt01sjt9KKIubxzRXCVU7MlmHpAZK2biQ-umtRa3t9z5ZId=w800)
(https://lh3.googleusercontent.com/pw/AP1GczPZWSd5bnijkNUiVc42JYKb2u92dtJKGw55Id25ICGMSYOC3qvGXLGgWR1mXTf3P_gwi8gupZN5xMBO1BnjVlLRmXrbA7SOxiGVUj2_980um5Wb4ahq=w800)
Most of the components are now here, but after playing about with layout - I've decided to order up a Victron Lynx for all the power distribution in the component area instead of the individual relays/fuses/bus bars I have from the old van installation. I've had mixed success with the Lynx in the past. On the plus side, they do provide for a very compact installation incorporating fuses and positive/negative busbars in a small form factor. On the con side - they force your wiring to work around them, and require fuses on circuits where you might prefer relays (solar disconnect, etc.) Individual busbars and fuses/relays can fit in very narrow areas and are far more flexible in location, even if they take up slightly more space. The ex-battery box location doesn't have those limitations, so the Lynx looks to be a good solution here.
For those who have never used it, 80/20 is the bomb. And, given how many of you are of a certain era - you just might have erector set flashbacks. ;D
As well as Erector Sets, 80/20 reminds me of Tinker Toys, the way you can build complex structures with a few basic shapes,
80/20 strut tubing is neat stuff, the genius grandchild of Unistrut, the earlier strut system that is widely used today in almost every commercial building.
https://8020.net/
I wish 80/20 was available locally, it would be fun to use in many projects. It is getting so hard to buy project materials locally.
In my area during the last few years, we have lost the one good hardware store, the closest auto parts store, Joanns, Fry's Electronics, the metal supply house, and a West Marine store., all places that once provided numerous parts.
The local Home Depot and Lowes have limited selections of many basic materials.
Unistrut too is useful for hanging or supporting heavy things and it and its supporting accessories can be purchased at most big box hardware stores. It has been one of my go-to basic building materials for over 50 years for both construction jobs or when building trucks and camper accessories, it's great for custom roof racks.
Steel Unistruct is weldable with a common arc or MIG welder and is inexpensive for a very strong material.
Unistrut Channel: Selecting the Right Strut for Your Application (https://unistrutstore.com/blog/post/unistrut-channel-selection).
Larry
I've never used 80/20 myself, but I see that McMaster-Carr has a wide array of similar-looking struts and accessories (https://www.mcmaster.com/products/~/t-slotted-framing-and-fittings~/?s=80%2F20). Perhaps some of these are compatible with 80/20? If so, McMaster ships and delivers very promptly.
Secondary alternator installed today. My days of wrenching are mostly behind me, so I had a good friend/master mechanic tackle it.
It was a surprisingly quick and easy job for him - less than 2 hours. I plan on wiring it up to the house bank and Wakespeed, but those are relatively trivial tasks.
With respect to future difficulty in accessing things in the more crowded engine compartment - he didn't think it a major deal. The main component that it blocks is the factory alternator, but he suggested it might add 30 minutes at most to replacing that.
Here's a view of it in place, shroud, fan and air filter assembly removed. Looks to be a very high quality kit.
(https://lh3.googleusercontent.com/pw/AP1GczNZ6Yy3UHxn2b4NaAHgoSDI-m8BTIa7K5KNO9IKQBhKf5VwdRyiApUdIllzy8R-H2Ig9rnbT6AwSxLgnSXSuUt1Ok0z80WRZKVSD3s1CB8n4GD0Y5cj=w800)
(https://lh3.googleusercontent.com/pw/AP1GczMrxrDNp_p3L8iTrRB6W-e2yRcJ83xLYWd2jdmWwEpfvyh1pmjZo0Iy5oxgENElpozXwixswWEt7QEHv5IKGa3AZmMOGnY7lDNT2MQO8SwzdUSlKsPq=w800)
Lots of wire pulling today, nothing too exciting. A few small tips to share.
I put SmartPlugs on anything that has shore power. As some of you have noticed who have done the same, doing so on the LD is a chore., And, once done it leaves a small unfinished edge around the rectangular SmartPlug as it doesn't completely cover the round Marinco 30A inlet.
I had a buddy 3D print a trim piece for me. If anyone wants the STL file, let me know and I can supply it.
(https://lh3.googleusercontent.com/pw/AP1GczOciOTjyjP3mVRs5EsAj2kDQBl5l8DyxO3nJ-q8g4OR31tzeFFxbZgzP8birpXAB-0rAXyJnzGtqyNJvbY_QDdybPUYR82dUrNtnsc3Qd_WIORF1SY5=w800)
Down in modified battery compartment, I got out the 3" hole saw for several 4/0 and 2/0 cables that need to come in. Found a cheap 3" flange on Amazon, it finished things up nicely and gave a smooth edge where the wires will come through.
(https://lh3.googleusercontent.com/pw/AP1GczPDEjSBRH3_9zX277UF07a8Hh6htSSZwdAX4IWbygZG9uFm7Xk-WwNaIEPtB1q_I_9nzhGCYLWlNb_B0WJFeY3OuBJ1enGRzILajok6qVBdMAxfqN91=w800)
Lastly, I need to pull a pair of 2/0 cables from the new alternator through the lower compartment as well as a 4/0 for the new chassis ground. I ordered up an assortment of glands, and a 3/4" NPT gland fits both 2/0 and 4/0 welding cable. This will provide a weathertight entrance into the lower compartment from under the coach body.
(https://lh3.googleusercontent.com/pw/AP1GczMJCqdDGWoLI7nJDk0Wg3NwmDIe9DgWmBLIeivw3In7DhA-dSRx7K0Hjn8lRgd1vex9e3uFqqDWKujNR0eMHiVUDb4rVZGZ3Ai72an5u11NeDfTDyge=w800)
Does anyone know of a common source for ACC power in the engine compartment? I need something that comes on with the key for one of the Wakespeed connections. I'd prefer to do it under the hood instead of the cabin fuse panel if possible, as I'm already running a wire loom from the Wakespeed to the alternator.
It's much easier to find an ACC wire under the dash and run it through a grommet in the firewall. All the wiring under the hood is wrapped and would require opening the harnesses to find a hot ACC wire, if one exists.
Looking at the E-Series wiring manual for our 2003, I can't find any ACC wires under the hood; they all appear to be under the dash.
Larry
All the wiring under the hood is wrapped and would require opening the harnesses to find a hot ACC wire, if one exists.
Yep, fetching from inside the cab is easy - but one place I saw access in the engine bay was the large fuse/relay box, and the Wakespeed harness will go right by it. I was hoping something in there might work, but if not - poking through the firewall is not the end of the world.
Hi Will; One place you could pull a signal from is the Fuel pump relay. If the engine isn't running, the fuel pump will be off, and you won't be trying to take charge from a non running alternator. A 30 Amp fuse (green) is in my relay / fuse box. The relay is there also. A separate wire could be connected inside the box and run through the bottom (there are some un-used sites locations). RonB
The fuel pump is activated when the ignition switch is in the "On" position. Will wanted an ACC wire that is under the hood. I know of nothing under the hood that is powered by the ACC circuit; everything on the ACC circuit is under the dash, including its fusing. Not knowing much about the Wakespeed's needs, I would guess the fuel pump relay or even the ignition circuit could be used to turn on the Wakespeed, both have wiring access under the hood.
Larry
Does anyone know of a common source for ACC power in the engine compartment? I need something that comes on with the key for one of the Wakespeed connections. I'd prefer to do it under the hood instead of the cabin fuse panel if possible, as I'm already running a wire loom from the Wakespeed to the alternator.
Sad that Ford no longer supplies links to its "Body Builder Layout Books" for early E-series chassis. I used them to find "extra" circuits.
A 2002 should be similar to my 1996, though. If so, there may be an orange wire in a 4-pin connector under the hood that gets an ignition-switched 12V signal out of the trailer battery charge relay. That connector is likely not far from the engine compartment fuse box. Look under the hood, in the rear on the driver's side, and perhaps under the plastic "cowl," for an unused 4-pin connector.
<edit>I found a copy of the relevant "Electrical Wiring" section for a 2015 E-series on line. Link is here (https://madocumentupload.marketingassociates.com/api/Document/GetFile?v1=4311615&v2=060118093748&v3=60&v4=d7acf5e712115cbc0eafe1901dc1ebd92e50dfc7abfd800f784b3568&v5=False). Download it from Ford while you can!</edit>
Mark H.
Will wanted an ACC wire that is under the hood. I know of nothing under the hood that is powered by the ACC circuit; everything on the ACC circuit is under the dash, including its fusing. Not knowing much about the Wakespeed's needs, I would guess the fuel pump relay or even the ignition circuit could be used to turn in the Wakespeed, both have wiring access under the hood.
Bad/incorrect wording on my part, sorry about that. Don't need an ACC circuit, just need a switched hot.
Wakespeed calls the hookup "ignition" - and I like the idea of using the fuel pump relay, as I can't see any reason to activate the Wakespeed unless the engine is running. Wiring diagram for the Wakespeed attached.
Thanks for the idea, Ron - I'll search that out in the fuse/relay box and verify with Wakespeed tech support that's an acceptable option.
Bad/incorrect wording on my part, sorry about that. Don't need an ACC circuit, just need a switched hot.
.
Well, that simplified things. There are plenty of options for an ignition hot wire under the hood.
Larry
Plenty of progress made, along with a few minor changes to plans. Everything is wired up, DC functions verified and everything AC now runs great off the Multiplus inverter. I can tell the solar is hooked up correctly and working, but with the coach inside the garage for a few more days more thorough testing will have to wait.
(https://lh3.googleusercontent.com/pw/AP1GczPUZP0fNET2DMsMShx567dMZMHwMSuxZBvMMbMToMPOXgHJJM457jTlzUmNTYYPxtVrrm0AldRynFVf8PPSmQzQ-hUYicBZSSwm8xVFelcTAsZKcm0d=w800)
(https://lh3.googleusercontent.com/pw/AP1GczONsEOcqUdKbE0ODw2b6Fv0bh7nk5_Uar4qQb2u7PhmapobndXbOiSh0GCbO3N_MRoNZfduHPbQZpbNXsgygWk-YJqGqUbIc-ZkSjjVosj6hG20DoJh=w800)
Here's the cabinet area under the fridge. Thin ABS panels are ordered up to trim it out, they'll be attached to the 80/20.
(https://lh3.googleusercontent.com/pw/AP1GczNEbMqkNcsLjDdepsIvEGPKqSttFVnpwNOSs7Ewc680lqhB-HE-KLRW4nyKQDsNmOKrvK3daas-GA_XJdiQhKXyQ2TW-3nnVDaLBTcYtCBda2bmDmYB=w800)
Changes:
- I'm no longer planning on hooking up the generator. The large 2AWG starter wire that terminated in the old battery box has been coiled up and stored in the wire raceway in front of the water tank.
- With no generator in the picture, the transfer switch has been bypassed. Related: With no generator and the additional filtering done by the Multiplus in addition to the existing EMS, I've reinstalled the jumper in the EMS resulting in a shorter delay upon shore power being connected.
- With the DC converter bypassed and no longer needed, a dedicated AC outlet has been installed using the 15A circuit that fed the DC converter. Now...when my lovely wife fires up the hair dryer, she won't have to ask me to turn off the espresso machine. :D
- All new 6AWG wire was run from the new house 12V bus to the DC side of the power center. I hated having that hidden circuit breaker in the factory feed, and with the 12V feed fused at the new Lynx bus bar there's no need for it. However, removing it left only two options. Splice in wire at the hidden breaker to extend to the Lynx bus bar, or install a new, continuous run. Everything was already opened up, the run was relatively short so I chose not to cut a corner.
The secondary alternator has been installed and wired in, along with the Wakespeed regulator. Initially, I was planning on installing the Wakespeed hidden away with the Victron components - but there's an idiot light on it that can be used for troubleshooting, so having it somewhat visible is preferable. I found a nice spot for it tucked up high in the cabinet beneath the fridge, with the face pointing towards the back of the driver's seat. The Wakespeed light can seen, access for reprogramming is much better if that's needed and this location had the added bonus of covering up holes in that wall left by an old, small inverter switch.
(https://lh3.googleusercontent.com/pw/AP1GczPfc4-zNK4sHKFLGtoBchsv5_pff_EmGK5kNrNhCCmBTJNEt8d_o52R3SEbyFGoWzHXtrS-0zqOgPi2cJDT_8T_Za9kempjfuzG4bxnRwJrYWenhMh5=w800)
My mechanic is coming back in the next couple of days to button up the engine bay, then I'll proceed to testing the Wakespeed charging. I'm running the battery bank down right now, planning to get it down around 20%. I'll then check how many amps the aux alternator puts in at idle while bulk charging to see how it compares to shore power using the Multiplus. I'll report back on that in a few days.
Hi Will, That all looks very nice. I know what it takes to get the wires right. Still need to waterproof that opening where the battery slide out rails, and the battery box were.
On my T/K I repaired the aluminum, replaced the water tight gasket. I also put another gasket on the edge of that door. It took some silicone grease to get that door to close. I'm not sure how much access you need other than to use that power switch. RonB
Will, that is one sweet installation. Great job. Straight and plumb! You used every inch available in that small compartment for sure.
Ron, on that compartment, I just installed a little Reflectix and some aluminum foil tape. No problem with any water intrusion.
jor
I read about this a few days ago, and parts just arrived to hook it up. Basically, just a custom wired ethernet cable and a terminator. Connect the cable from Wakespeed to Cerbo, plug in terminators - done.
With the latest firmware on Wakespeed and Victron Cerbo, they can communicate over VE.Can. In layman's terms - this provides for the alternator to appear on the Victron display as shown below. Absent this setup, the DC current from the alternator would include the Wakespeed - but it would not be delineated, nor would any of the alternator specific information on the second screenshot be available.
Screenshots below. Should have useful data coming from this shortly.
(https://lh3.googleusercontent.com/pw/AP1GczPjxGFKSsWzlrV7livWL2eVeZ9fxoorKdFkrRGyVb5Nb1J1HakotOdZJj1WBpAAAyGq2U4a_EetK2G2KRZ383P2m2k-gpn3mIN-KJCbyzHY2ZfR0FFH=w800)
(https://lh3.googleusercontent.com/pw/AP1GczP1zjMZ_CGTjNld-9FjYz45MpKa71KTyvApHsFberV124_K6VK5Y1U3PtSKGe-N1O9UgzA0grnuPK6V-KyZ6L_ZIVruVIQ5eu2jB4lt-HNT3JgJCKW2=w800)
Success! Initial data looks very promising.
I tested for about 30 minutes with the engine running, and the new secondary high output alternator is delivering 175-190A of DC current back into the batteries - at idle. No increase in temps on the battery side, and only slightly elevated on the alternator.
The current being delivered from the alternator is actually higher than the Victron Multiplus charger provides from shore power - sort of. I don't have a 30A connection in the garage where I'm doing the work, so I use the Victron Digital Multicontrol to back off the incoming amps from shore power to 18A since I'm plugged into a 20A circuit. With maximum incoming amps derated to 18A, I'm seeing 110-120A DC input to the battery bank from the Multiplus charger. I'm fairly certain the alternator will deliver more power than the Multiplus, even when hooked up to 30A - but I'll test that over the next few days.
Regardless, the alternator is easily putting more amps back into the system than I can imagine taking out. The onboard Onan may have been run for the last time.
That is a beautiful installation, it looks like something from an expensive yacht. You have more information available than ever before. Working with 4/0 cable is a PIA.
I see the battery switch has a warning tag not to turn it off when the engine is running, I assume to prevent surges from damaging the alternator's diodes. Marine installations have used alternator surge protectors for decades to prevent damage, I installed one in our 1983 LD when switching from a 63-amp alternator to a 150-amp alternator.
APM-12 - Balmar (https://balmar.net/product/apm-12/)
https://balmar.net/wp-content/uploads/2022/09/PDS-APM-12.pdf
Battery terminal fuses are handy and a nice touch. Did you increase the size of each fuse to compensate for the increases in the amperage at the end of the daisy-chained battery cable?
Larry
Thanks, Larry - I like how it turned out. And yes...4/0, even with the more flexible welding cable is not very forgiving in tight spaces. Layout took a lot of thought to accommodate it where needed.
Getting data from these systems has gotten so easy, and the added expense for monitoring if using Victron components is minimal. A Cerbo GX provides insights into so much, and is a little over $200. That's actually all you need if you don't mind monitoring from your phone, but a cheap tablet can attach via wifi as a remote console to view the output. I've a stack of Amazon 7" Fire tablets I picked up on sale for $50 each, they work great for this task and can be placed anywhere in the coach I can pull a 12V connection.
RE the battery terminal fusing - there are so many thoughts on that, and a good number of installers (including AM Solar when they were in business) don't fuse at the battery terminals at all. Rather, they depended on battery BMS's and a large class T fuse right off the battery bank. I'm more paranoid about such things, so I used both. I fused each battery with a Blue Sea 300A fuse, then the entire bank with the class T 400A fuse shown just prior to the main disconnect switch.
I've heard of the Balmar APM device, but need to research them more. I recall seeing some comments in other forums about their efficacy in installs like mine, but I don't remember the details. One question I immediately have, though - they seem targeted at protecting the diodes in the alternator. Given the 2/0 cables running from the alternator go to the common house bus bars, my primary concern with load dumps is not the alternator - it's the numerous and expensive pieces of equipment that are fed by the same common bus bar the alternator is attached to. If the Balmar is only protecting the alternator, it would seem all of the Victron equipment and anything on the 12V side of the world are still vulnerable if the master disconnect switch is turned off while the engine is running.
An unexpected turn, relatively minor in the grand scheme of things - but wiring needs to be changed from what I was told originally. As seen in a screenshot a few posts up, incoming amps were shown correctly on the battery bank - but the alternator data was missing.
Turns out, it's only possible to get that data by installing a second shunt on the alternator positive feed. I've patched one in to test, and it does work - but permanently installing the shunt is going to take quite a bit more work.
Shown here is the final, proper output. At idle.
(https://lh3.googleusercontent.com/pw/AP1GczN-667s2RiHRx1bTLtVJb3vanMnEAlAlk9w3J8OR3J16oehKINwB2z-_d2larbwbLPRf9FPOn2ZUJiZkZHG7_Jcg0YQxNDib14dGJp9JGtPcnDkwozQ=w800)
Will, you know the following, but some casual readers might wonder about it.
The main shunt is intended to measure the net current into or out of the battery(ies), for the purpose of tracking their state of charge (SoC), and is displayed as a percentage of the total capacity of the battery(ies). SoC is the stored energy, which is what is the most interesting. Any charging source, whether solar, generator, alternator, or converter (from shore power), will see its output current distributed among the various loads on the system including charging the battery. But this distribution of output current is not relevant to the battery SoC.
If you are curious about the total current the alternator is producing, then a second shunt is going to give that to you. It is interesting in convincing oneself that the alternator is not going to self-immolate. If the reader wants to see an example of the current distribution that Will is interested in from the alternator, look at the solar controller output current compared to the battery shunt current. I typically see the solar output higher than the battery charge current by something like 0.2 A to a couple of amps depending on which miscellaneous devices are running, like detectors, fans, refrigerators, phone chargers, etc. Remember to look at the solar OUTPUT current, not the input current, for this example.
Most of the time, the alternator current will be modest (a few amps). The time when it will be large is when the battery is discharged enough to allow the BMS inside the battery to accept a bulk charge, like 100A, 200A, or whatever the alternator limits at.
Good info, Keith. While there are many variables coming and going in the system as you pointed out, this is one reason I'm really a fan of integrated Victron systems. Their dashboard is the best I've seen at zeroing in on what's important. Pretty much anything of concern is obvious at a glance.
However, as is often the case with such things - it's not a bad idea to apply a little critical thought to what is being displayed. There are so many variables in how things are hooked up and configured and it's easy to fall prey to the ol' "garbage in, garbage out" mantra. Some of the keener eyes in the audience might have noticed one such oddity with my last screenshot.
I didn't catch it until a friend pointed it out. However, the alternator watts - and subsequently hand calculated amps - were nowhere near what the battery watts/amps were showing. There were no loads or other charging sources active while the engine was running, so this doesn't make sense to me. And, there's essentially an uninterrupted path from the alternator positive and negative to the lithium bank, so there's nowhere for the difference in displayed current to be going that I can see.
Further adding to the confusion, I've been having a conversation with Wakespeed about configuration and the second alternator shunt. Mentioned previously, but there are two direct 2/0 cables from the alternator going directly to the Lynx bus bar positive and negative. Originally, and when the screen shot was taken I'd put the shunt in the positive alternator feed just prior to it attaching to the Lynx positive bus bar. This is how the docs show it, and many in online forums elsewhere suggested this option. However, in a later conversation with Wakespeed they mentioned the alternator shunt could go on either the positive or negative 2/0 cable between the alternator and bus bars. So, I switched it to the negative cable. Primarily because, there's no shunt I've found that has insulation over the posts, and having a "live" shunt out in the open was concerning to me.
Upon starting the engine back up again with the shunt on the negative alternator feed, everything did work - but the data in the Alternator box now matches the data in the Battery box in the display, nearly perfectly. This makes no sense to me, and I've asked Wakespeed for an explanation - but perhaps somebody smarter than me here has a theory. ;D
Usually, a detailed, accurate electronic schematic of the wiring in the coach will show an obvious reason for the difference which will not be apparent from the abbreviated interconnection diagrams.
Steve
Hi Will; The positive lead shunt can't be referenced by any other meter that is reading the shunt in millivolts referenced to the real ground (chassis). A separate 'floating' meter connected only to the positive shunt leads should read the proper current levels. So your system that is switching to read different shunts, measures from the chassis ground reference. Your Wakespeed shunt should be in the ground lead. RonB (I'm not smarter, just more experience in test and measurement, my speciality in the Navy)
I don't have a complete wiring diagram, but the attached shows everything attached to the house side of things with the exception of the alternator and secondary shunt. That portion is relatively easy to describe.
Also, the attached Victron/lithium schematic contains a generator, transfer switch and DC-DC charger. I have none of those, but the rest of the wiring matches my installation exactly.
The dual alternator/secondary shunt wiring is very straightforward.
Secondary Alternator Positive (B+ post) --> 2/0 AWG --> Lynx Positive busbar
Secondary Alternator Negative (mounting bolt directly on alternator) --> 2/0 AWG --> Lynx Negative busbar
When installing the secondary alternator shunt for testing, it is inserted between the 2/0 cable and the Lynx bus bars. When on the positive bus bar, the current is high in the Alternator box and doesn't match the Battery box in the Cerbo display. When the shunt is on the negative, the current values match.
Cannot read any printing on this image, but the battery shunt seems to be correctly wired. Since the alternator case is grounded to chassis as is the Lynx negative bussbar, its shunt could not be wired similarly, so I am not sure what you have done to accomplish that?
Steve
Hi Steve; The body of the Alternator should be grounded to the chassis, but there shouldn't be any connection to current flow. Only the output wire negative should go to the buss bar. Similarly the bussbar serves as a common tie point but does not connect current flow to the chassis. A connection point at the common bussbar should go to the current shunt, and then the 'not hot' side of the shunt should be connected to the chassis. Other items grounded that connect to the chassis should be connected to the chassis closeby. Iron isn't that good of a conductor, only surviving as a current carrier because of a large quantity of iron. Ground loops because of slight but still there, differences in potential, between grounding points can cause issues. (usually just small measurement errors).
I couldn't read the notations on the diagram. I went to the internet source and I couldn't read it either. They really didn't mention much about the alternator at all. RonB
Similarly the bussbar serves as a common tie point but does not connect current flow to the chassis.
Ron, it is hard to read, but the diagram clearly shows a black cable connected from the negative bussbar to "chassis". The bussbar is also connected to the "low" side of the battery shunt. The "high" side of the shunt is connected to the battery negative. This is as it should be. This means the alternator body (negative) is equi-potential to the bussbar negative. Any small voltage drop due to chassis conductive imperfections would simply result in an error reading. So, it is still a puzzle to me where the alternator shunt fits into the picture...
Steve
Here's a wiring diagram that I believe shows all electrical connections.
RE the alternator shunt - the diagram shows it in the current location, the alternator negative feed to the Lynx. This location is reporting current consistent with the SmartShunt. The original location for the alternator shunt that displayed significantly higher current was in the alternator positive feed to the Lynx.
Will, is the alternator body attachment somehow isolated from ground? If not, then this hookup should not work. Else, in effect, you show both sides of the alternator shunt connected to chassis ground.
Steve
Will, is the alternator body attachment somehow isolated from ground?
No. I verified there was excellent continuity from the alternator case to chassis ground right after it was installed.
Reason being - when I first saw the wiring diagram from Nations Alternator, they showed a dedicated negative cable going to the negative bus bar for the house side of things. Knowing I had run a short, 4/0 cable to the chassis frame from the Lynx distributor negative bus bar, and knowing the alternator case was grounded to the chassis - I was hoping to get away with a single 2/0 feed from the alternator positive back to the positive bus bar on the Lynx distributor. It should be clear by now there are gaps in my electrical knowledge, but my assumption was the alternator chassis would already be grounded to the Lynx negative bus bar via that new frame connection I put in. The 4/0 cable I installed to the chassis frame from the Lynx is very short (about 18"), and I sanded the connection point down to bare, shiny metal.
However, Nations got back to me and said their recommendation was always to run a dedicated 2/0 cable from the alternator body (via one of the mounting bolts) directly to the Lynx negative bus bar. They prefer not to trust chassis ground, for whatever reason. So, that's what I did.
If not, then this hookup should not work. Else, in effect, you show both sides of the alternator shunt connected to chassis ground.
Well...I don't know what to tell you Steve. I'm not a huge believer in magic. But, here's what's showing now with the shunt on the alternator negative. ;D
(https://lh3.googleusercontent.com/pw/AP1GczPhZCTCFmTPmxoC-6O4C5Gflxoeorxzz3V_Sw6q7qb3zNbbcAkPTAFcKq9TZZ7W7HcGsZnv2qEIgBnGPhdS_GpjT0ZdL4rgGNr8CSaorGjOtFsoEqnk=w800)
Everything is hooked up just as shown in the diagram I uploaded. More details on the new alternator shunt, not that I can see how it matters - but I disconnected the 2/0 negative cable coming from the alternator case bolt where it attaches on the Lynx negative bus bar. I connected it to the shunt on one side, then ran a short, 10" piece of 2/0 cable to the Lynx negative bus bar on the other side. The two current sensing wires from the Wakespeed are attached to either side of the shunt as shown in the diagram.
Excuse the ugliness, this is a temporary testing setup. And, when current was showing way high - the same setup shown below was in place, only the shunt was in the alternator positive feed going to the Lynx.
(https://lh3.googleusercontent.com/pw/AP1GczNj3K5oEg5mc_b1lKqtvBZqJh7b5Agoo3aCkn9CRxuuDHmHRssWbHVZ7ryQnofxy2JZwEeYpGDD_WwDRAvWFygbso--mJk-wW8-mJTA7EMMWbNjhkrv=w800)
Hi Steve and Will; In the olden days, particularly GM chassis, the Alternator case was the conductor to ground, hence the 'one cable (+) was possible. But that flexible woven link from the engine to the chassis had to conduct all of that current. That connection just isn't up to the high powered 'non engine' requirements today, especially considering the charging of house batteries and other auxiliary items like hydraulic levelers, winches, lighting and equipment not actually involved in running the engine itself.
In more higher powered alternators the negative connection may not be related to ground even. The ground is still necessary for the voltage and current regulator to control rotor current and field strength. But the stator where the actual power is generated, needs it's own conductor.
That cable properly should go to the shunt, that proceeds to chassis ground through the Lynx distribution box (4/0 cable). In the diagram, that voltage goes to the Wakespeed WS500 controller. That, I'm sure isn't that controllers only information about current.
The smart shunt information goes to the Cerbo unit as expected for display. The Wakespeed controller also has a data input to the Cerbo.
Will, your MB has similar equipment to Tim (T & F)'s rig, also a MB ('08). (no second alternator, and with S.O.K. batteries). He used aluminum Unistrut rails on his roof to mount 800 watts of solar, with provision for expansion to 1200W. Do you intend to expand your solar? RonB
So, the current from the alternator takes two parallel paths to the ground point the shunt is connected to - one path being through the chassis, the other through two lengths of 2/0 cable and the shunt. The cable has a resistance over 20' of less than 3/100 ohm, and the shunt probably 0.0001 ohm. The chassis path is probably 1/2 ohm or more. That means that over 99% of the current flow from the alternator passes through the cable and the shunt, yielding an accurate measurement. Just keep those connections tight!
Steve
So, the current from the alternator takes two parallel paths to the ground point the shunt is connected to - one path being through the chassis, the other through two lengths of 2/0 cable and the shunt. The cable has a resistance over 20' of less than 3/100 ohm, and the shunt probably 0.0001 ohm. The chassis path is probably 1/2 ohm or more. That means that over 99% of the current flow from the alternator passes through the cable and the shunt, yielding an accurate measurement.
Just keep those connections tight!
Chassis grounds have been known as electrical problem spots since the beginning of automotive electrical when some genius figured a car's metal frame could replace the ground wire in an electrical circuit. Today, cars are still wired this way, and they still have ground problems.
Poor or multiple ground pathways are a reason why high-power radio gear and other voltage-sensitive devices suggest or require that each device have both positive and negative fused wires running directly to the battery's terminals or bus bars. Reducing induced electrical interference is another reason.
Through the years, I have spent hundreds of hours chasing down electrical issues that were traced to poor grounds and/or multiple ground pathways..
Strange things happen when poor, multiple, or missing grounds are encountered.
Steve's advice applies to all of us with an upgraded electrical system to often check the hardware securing the cables and periodically check for voltage drop over each cable when the system is under load, both when charging or discharging. It can be surprising to find an otherwise good-looking cable has a bad crimp and high resistance. In high amperage systems, a small amount of resistance can waste a lot of power and potentially burn things up.
Larry
Do you intend to expand your solar?
I'm on the fence, but am leaning that way. Currently I have 3x100W panels, wired in parallel.
There's some agreement from those who know more than me that mixing and matching panels is not ideal. So, were I to bump to 500-600W I'd likely get all new panels just to be sure and repurpose the existing panels to another smaller installation. Panels aren't that expensive these days, and the additional labor would be minimal. I don't do panels - I'd farm that out on my next trip south through Oregon.
I'm on the fence, as there's a school of thought that utilizes no solar, or very limited amounts. Rather, a substantial battery bank combined with direct and rapid charging from the alternator. This philosophy was shared with me by AM Solar when I did my recently sold van, and it worked very well - I had no solar on the van and never needed it. With 800AH of lithiums, that was typically plenty of power for 3-4 days - and our usage typically had us staying somewhere less than that, then driving several hours to the next stop. The batteries would easily top off during the drive.
The difference between the van and the current installation was a shared alternator vs. dedicated auxilliary. The van charged via a Victron relay. Not quite as fast as what I have now, but we never needed more.
With the setup I have now, should I find myself staying somewhere longer than a few days or the drive between stops is short - I can always let the engine idle for a couple hours to top things off adequately. However...adding 500-600W of solar isn't that expensive compared to what is in there now, and I've already installed the MPPT to handle that many panels. I'll probably do it, mostly for peace of mind.
"I can always let the engine idle for a couple hours to top things off adequately."
That may not be the best idea, for a couple of reasons. First, alternators don't generally put out their full rated power at idle speed, so this can be a slow way to charge batteries. And second, my understanding has always been that it's not good for an engine to idle for hours at a time. (Auto mechanics, please correct me if I'm wrong.)
There's plenty of debate on extended idling, but my research on the V10 in particular has me feeling quite comfortable with it. Other may feel differently.
The alternator output issue though, is a non-issue in my case. Yes, standard alternators may not put out significant amps at idle. The Nations 280XP is designed for very high output at idle - check a few posts back for details. While the output varies depending on many factors (temp, battery SOC, etc.), I've seen it put out more amps at idle than my Multiplus does on shore power.