My AGM's were installed in June 2021.
I'm planning ahead a little for when they need replacing.
I may do it sooner.
I have the stock 2 panel solar system in my 2021. I have the Lithium charge adapter panel add-on for my electrical panel.
A few questions.
Are the 2 AGM batteries replaced by one Lithium?
In other words, no need for the 2-6V battery arrangement any longer?
What are some good brands?
What size for my modest system?
I'd like to have built-in BT monitoring.
Hi Ted; The lithium batteries come in 12 or 24 volt versions. You want two 12v batteries in parallel, to replace the two 6v batteries in series that you presently have. The built in battery management system inside of each battery takes care of balancing the internal cells.
I got the S.O.K steel cased batteries, because they take up less room, and water exposure should never be a problem on your motorhome. Not like a boat! Mine are an older version and don't have these features, but the new ones have internal bluetooth, internal heaters, and are UL approved. SK12V206H | 12V 206Ah LiFePO4 Battery Bluetooth&Built-in heater | SOK Battery (https://www.us.sokbattery.com/product-page/sok-12v-206ah-lifepo4-battery-bluetooth-built-in-heater?ref=o0xyocwb&sub_id=)
Two of these fit in my standard sized Lazy Daze battery box. If you have an upgradeable converter, usually just a jumper move, changes it to a higher voltage to more efficiently charge the Lithium batteries.
My batteries are mounted on end to fit better, One side handle can be removed to stand them on end.
You can use the internal BMS information, but it is still best to have a stand alone battery monitor also. Many people use the Victron 712 display with shunt: Generic BMV 712 Smart Battery Monitor, Smart Battery Monitor with Battery... (https://www.amazon.com/Generic-Battery-Programmable-6-5%E2%80%9170VD-Genericmfuew13hpb/dp/B0D9KBJYL9/ref=sr_1_8?crid=24WVKJWP666ZH&dib=eyJ2IjoiMSJ9.K6P6OTMykPYfbO23IqlJdDrEQReN5veAwu3jRBSOcWW2kGY_AKOeocYWPMA6Po1oEa41qUUpTlwKxZJrJ_fDGg.2-D_Wd6j1onMoVQO47h-udrhivaomFyHi_pQzUMVsRA&dib_tag=se&keywords=victron+712+monitor+with+shunt&qid=1747496699&s=industrial&sprefix=victron+712+monitor+with+shunt%2Cindustrial%2C180&sr=1-8)
RonB
I bought 3 100 ah mini Lithium batteries from WattCycle. All 3 fit in the LD battery box without any modifications other than the wiring connectors. I enjoy having 300Ah of usable capacity. My original converter from Parallax started acting up a while back, so I replaced that with a 75 amp unit from PowerMax. I added a Victron shunt and a Victron Orion 50 amp DC to DC charger to protect the alternator.
Lots of options here but I'm thinking you may want to consider adding more panels on the roof to take advantage of the new lithium batteries.
I did exactly what you were trying to do, but mine is a 2006 mid bath. With some good input from people on this forum, I debated heavily the issue of adding a DC to DC charger, which I finally did. I installed three.LiTime 100 amp 12v batteries (maybe not the best but who knows… They were cheap ) in the small cabinet on the floor under the refrigerator. I needed to clear out room in the battery box to put in the Victron DC to DC charger because I wanted to protect my alternator.
I made sure I got batteries that included a BMS with Bluetooth connectivity so I can monitor charging from the app on my phone. Because I have room now in the battery box I was able to put everything there and I’m sorry that I don’t have a picture to show you. At the risk of people criticizing my design I am attaching here a rough block diagram of how my new electrical system. I only have two original solar panels, but the batteries charge quickly now. Also, I had to move a jumper on my power converter.
Everything works absolutely perfectly and the project wasn’t hard at all, even though I don’t know what I’m doing. Ha.
Lots of options here but I'm thinking you may want to consider adding more panels on the roof to take advantage of the new lithium batteries.
That's definitely a good idea but in the meantime I'd like to be able to pull into a campsite with no hookup and take advantage of full capacity for more than 3 days or so no matter if they are recharging or not.
Hi Ted; Whether your LiF batteries last three days, with 2 solar panels depends on your usage of course. The LiF batteries charge faster than AGM (lead acid), so you will get more, quicker from the solar. (are the panels still 100W each?).
You will be able to draw the LiF batteries down to 10% routinely without damaging them, unlike lead acid batteries. If your usage is light you may never need to add more solar panels. Driving will provide re-charging from the engine alternator. Plugging in to shore power or running the generator will also charge the batteries quickly.
If you have the Blue Sky Energy solar controller, it is pretty simple to reprogram it by button pushing. This stops the 3 stages of power output meant for lead acid batteries, and increases slightly the output voltage to 14.4 volts to better charge the LiF batteries.
Your question about the converter: my PD4655VL has two fans but they don't operate often, and are very quiet. Your Parallax 8355 could have a bad fan, or a piece of paper, (dust, lint...). I don't think you need a new converter.
In my working days I was surrounded by very noisy fans 24/7 so they don't bother me, and when I don't hear them, as a maintenance technician, it does bother me. (another thing to fix). RonB
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Hi Ted; Whether your LiF batteries last three days, with 2 solar panels depends on your usage of course. The LiF batteries charge faster than AGM (lead acid), so you will get more, quicker from the solar. (are the panels still 100W each?).
You will be able to draw the LiF batteries down to 10% routinely without damaging them, unlike lead acid batteries. If your usage is light you may never need to add more solar panels. Driving will provide re-charging from the engine alternator. Plugging in to shore power or running the generator will also charge the batteries quickly.
If you have the Blue Sky Energy solar controller, it is pretty simple to reprogram it by button pushing. This stops the 3 stages of power output meant for lead acid batteries, and increases slightly the output voltage to 14.4 volts to better charge the LiF batteries.
Your question about the converter: my PD4655VL has two fans but they don't operate often, and are very quiet. Your Parallax 8355 could have a bad fan, or a piece of paper, (dust, lint...). I don't think you need a new converter.
In my working days I was surrounded by very noisy fans 24/7 so they don't bother me, and when I don't hear them, as a maintenance technician, it does bother me. (another thing to fix). RonB
Thanks Ron.
I also have the Parallax LiF adapter module.