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Topic: Questions on upgrading to Lithium batteries with inverter. (Read 496 times) previous topic - next topic
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Questions on upgrading to Lithium batteries with inverter.
Upgrading to 4 LiTime batteries and adding inverter questions.  Been reading posts about this but still have some questions.

In my new to me 2010 MB the house batteries are about 6 years old.  I’m thinking of upgrading the two current AGM batteries to four – 100wh Li Time Lithium batteries which have Bluetooth and heaters and adding a Giandel pure sine wave inverter model PS-2000SDR all of which are new and I already had before I bought the MB. 

The currently installed converter is a Parallax 7345 converter/charger and solar controller is an HPV-22B. Two factory installed solar panels are on the roof.  I’ve ordered and just received a PD4655V to upgrade the converter from Best Converters as recommended by them. 

Batteries are the same group size as what in there now so two will fit in the current battery box and was thinking of adding the two additional batteries in the inside compartment right beside the current battery box under the fridge.  I’d probably open up the battery box with some holes to the inside and add insulation on the outside of the compartment.   Possibly taking out the drawer below the fridge and mount the inverter below the fridge with two batteries beneath it.  I’ve ordered and just received a BMV-712 battery monitor as well. 

I have a battery disconnect switch on order. 

I’d like to occasionally run the microwave off of the inverter and possibly the house outlets or maybe just adding a dedicated outlet that’s run off the inverter.  I’d also like to be able to charge two electric bike batteries (probably not at the same time) off the inverter and once in a while to be able to let the spouse use a blow dryer while dry camping. 

Since the inverter isn’t a pass thru type how are people hooking these up? Has anyone tried using an extension cord(s) and/or dedicated outlets to somehow power the microwave?  Is adding an additional transfer switch by the shore power line the simplest solution?  Or add two transfer switches, one to turn off the converter when the inverter is on so you don’t have to do it manually?
 
Does the inverter need a disconnect switch like the battery disconnect switch as well?

What size fuses or re-settable switches would I need to add and where? What size welding wire (I was thinking 2)?

There is conflicting search information that says my HPV-22B is compatible with Lithium batteries if I leave the switch in the correct position but I’m not seeing the 14.4 volts needed to charge up the Lithium’s with the current batteries installed.  So is the HPV-22B compatible with Lithium batteries?

I might just add two batteries now with the new converter, battery disconnect switch, and battery monitor and add the additional batteries and inverter later in the fall if I don’t need to update the solar controller as well.

JohnF
2003 TK
Re: Questions on upgrading to Lithium batteries with inverter.
Reply #1 –
Quote
Has anyone tried using an extension cord(s) and/or dedicated outlets to somehow power the microwave?  Is adding an additional transfer switch by the shore power line the simplest solution?
I wired my Giandel inverter as a whole house inverter. I installed a second transfer switch.

Quote
Or add two transfer switches, one to turn off the converter when the inverter is on so you don’t have to do it manually?
I intended to install another small switch so that the converter would disconnect when the inverter was energized but I never got around to it. Since I did my installation I have had no need for the converter so I just leave that breaker tripped.
 
Quote
Does the inverter need a disconnect switch like the battery disconnect switch as well?
No. It's either on or off. I'm assuming you have the power button that comes with the Giandel.

I think you are going to want more solar to charge that 400ah of battery you have now.

You'll enjoy this project. Lots of bang for the buck!
jor

09 27' MB
10  Suby Forester
Re: Questions on upgrading to Lithium batteries with inverter.
Reply #2 –
We never run the microwave for more than five minutes, the consumption is low, so I leave it plugged into the inverter.
To switch to shore power, there is a short extension cord from the microwave’s power outlet, run into an adjoining overhead cabinet where it meets another short extension cord from the inverter. The power cord from the microwave meets the two extension cords in this location and this allows choosing to use either shore power or the inverter to power the microwave….cheap, easy to use and not a huge project to install.
The inverter doesn’t need a separate switch but it should be fused.

Larry
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze
Re: Questions on upgrading to Lithium batteries with inverter.
Reply #3 –
Opinion: I know it's tempting to just use the Giandel inverter you already have, but if it were me, I'd avoid the hassles of wiring manual transfer switches and remembering when to flip them, and just buy an inverter with pass-through capability. They're pretty common, and they're not that expensive.

"What size fuses or re-settable switches would I need to add and where? What size welding wire (I was thinking 2)?"

You'll need a class T fuse mounted as close to the batteries as you can manage. Figure the maximum amperage that your inverter can draw at full load, and then allow a safety margin above that. As for cable, take that maximum amperage and refer to the ampacity table. The table looks confusing, but here's how to use it: find the column with the temperature rating of your cable (75°/90°/105° C) and read down the plain (not "EngRm") column to the maximum amperage you need to handle.

For example, with a 2,000 W inverter at maximum load, you're looking at around 166 amps at 12 volts. Reading down the 105° C column, it looks as if AWG 1 cable would handle it. However, if you're using cable rated for 75° C, you'd need to go to AWG 00 (2/0 or "two ought") cable.

You'll also want a battery cutoff switch. Blue Sea Systems makes good ones.

Some advice about cable: welding cable is fine, but tinned marine cable is better because it will never oxidize. You can get Ancor marine cable by the spool from Amazon, and another good source is Custom Cable. They sell marine cable by the foot, so if you don't want to pay for 25 or 50 feet, it's a more economical way to go. They will also build cables to spec, complete with insulated power lugs, ready to install.

If you make your own cables, don't use battery lugs; they're flimsy compared to power lugs. You can get FTZ power lugs from Fisheries Supply. I haven't found anything as good.

Finally, don't use a cheap "hammer crimper." They don't make good crimps, and they're a pain to use. (Literally! I still remember when expert RV tech Mike Sylvester smashed his thumb while using one, and had to go to the emergency room.) Spend the money for a good manual or hydraulic crimping tool--others here can tell you what's best. (I'm being vague here because I've always used a big two-foot-long manual crimper, but they cost a couple hundred bucks nowadays. I recently bought a much more affordable hydraulic crimper, but have not yet used it, so I don't know how good it is.)
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"
Re: Questions on upgrading to Lithium batteries with inverter.
Reply #4 –
Andy,
I bought a hydraulic crimping tool from Harbor freight prior to installing the PV system on our tug.  It was relatively inexpensive and makes beautiful crimps.  It was money well spent.

Harold
2014 27 MB
Towd: Either the Jeep Wrangler or trailer containing the BMW R1200GS and 2 E-bicycles
Happy wife=Happy life
Re: Questions on upgrading to Lithium batteries with inverter.
Reply #5 –
Quote from: Andy Baird  - 

Finally, don't use a cheap "hammer crimper." They don't make good crimps, and they're a pain to use. (Literally. I still remember when expert RV tech Mike Sylvester smashed his thumb while using one, and had to go to the emergency room.) Spend the money for a good manual or hydraulic crimping tool--others here can tell you what's best. (I'm being vague here because I've always used a big two-foot-long manual crimper, but they cost a couple hundred bucks nowadays. I recently bought a much more affordable hydraulic crimper, but have not yet used it, so I don't know how good it is.)

Here's Steve's (site admin) write-up on his hydraulic crimping guidance

Compression Crimping
Re: Questions on upgrading to Lithium batteries with inverter.
Reply #6 –

Many years ago, I bought a Harbor Freight hydraulic crimper, it made poor crimps on larger cables, and it lacked the power to fully compress larger cables. (2/0 and larger).
Below is the crimper I have used for twenty years, it makes beautiful crimps in both large and small cable. It's pricey, something I bought when starting to do many electrical projects back when I worked on LDs.
https://www.fisheriessupply.com/ftz-industries-correct-crimp-heavy-duty-crimp-tool-ratcheting-model/94285 

Just as important, to make clean cuts in heavy cable, a pro-grade cable cutter is essential. What I use.
Klein Tools 63035 Utility Cable Cutter, Made in USA, for MCM Copper and 350...

For a good-looking finished crimp, use adhesive shrink-tubing with a heat gun.

Larry

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Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze
Re: Questions on upgrading to Lithium batteries with inverter.
Reply #7 –
Good advice, Larry. Those tools are pricey, but worth it. But I still have hopes that newer hydraulic crimpers may have improved.
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"