Any reason not to use a single 12v 200Ah lithium ion battery?

[GinnieWinnie]

I am researching replacing the group 24 22v lead acid house batteries in my 2018 Navion. Any thought on using a single 200Ah battery vs. 2 x 100 Ah batteries? The two batteries won't fit without modification to the tray under the step, but the single would fit perfectly. Anyone have thoughts 9n this?

[creativepart]

First, the typo. I assume you meant 12v not 22v.

So, assuming that 2 x 100 ah batteries are wired in Parallel, as they surely are, they are already seen by your RV a one 200 ah battery.

So, if the battery fits - go for it. In essence you're just replacing one 200 ah battery with another.

[BobC]

The only argument I've read against this is, if you have two 100Ah batteries and one goes bad, you still have 100Ah of battery power. If a single 200Ah battery goes bad, you're out of luck. I don't know how much of a real concern this is. This assumes, of course, that the single 200Ah battery will fit in your space.

[bigb]

If you can fit two true deep cycle 6 volt flooded golf cart batteries like the Napa (East Penn) ones you will get 230 ah and a lot more life cycles, like double or more life cycles than a 12 volt.
see this: https://marinehowto.com/what-is-a-deep-cycle-battery/
I have the same Sprinter chassis as you and the two fit fine but the hold downs need to be modified as they are taller.

[corvetteSS]

Check the BMS current limits. 2 100Ah may possible provide 200A continuous, vs the 200Ah may have the same BMS and only provide 100A continuous. Just check the BMS specs on both batteries.

[bigb]

I mis-read the post, the title says Lithium and I only saw LA in the text so my comment is not for Lithium

[Pianotuna]

Originally Posted by GinnieWinnie

I am researching replacing the group 24 22v lead acid house batteries in my 2018 Navion. Any thought on using a single 200Ah battery vs. 2 x 100 Ah batteries? The two batteries won't fit without modification to the tray under the step, but the single would fit perfectly. Anyone have thoughts 9n this?

Check to see if the bms is limited to 100 amps. I've seen that more than once and it is a royal pain. Consider SiO2 batteries instead.

[cruizerEd]

As long as the single 12V battery can safely and reliably provide the current you need I see no real issue. Redundancy would be nice but I'm not sure it is necessary. I would suggest getting a battery with a good blue tooth BMS and a heater if it is not in a conditioned space. Check out the youtube channel DIY Solar for battery reviews

[powercat_ras]

A full size microwave oven can draw 1,700 watts. I use a 3,000 pure sine wave inverter to run it and handle it's super brief startup current surge. It can take about 175 amps DC from my golf cart batteries when the microwave is running. This is due to the reduced voltage output of lead acid batteries under heavy load. The amps from Li should be slightly less as they will hold output at a higher voltage than lead acid batteries do, but still above 150 amps.

So when sizing your lithium batteries if you want to handle this scenario, you want to make sure your batteries can deliver that with a saftey margin.

So if your single battery is rated to deliver 200 Amps DC, you are good. Just make sure it does not have a Battery Management System (BMS) rated for only 100 amps output.

[Lefler39]

Randy is correct about the battery hold downs.

I have a 2018 Navion and I have modified and installed Battery Straps for (2) Lithium Group 31 in the battery compartment. I also lined the battery step compartment with Foil backed 1/2" foam to keep it insulated. I have a wireless temperature gauge for monitoring

[CJBROWN]

I run one 230A DIY lifepo4 and it's just dandy. 600W inverter, along with other 12V loads, the system never draws more than about 80A - BMS is rated for 120A max.

We got by with a pair of fla golf cart batts for 17 years, mostly dry camping - about 100A usable. So we get twice the capacity for half the space and a third the weight. Just fantastic.

Just know that most charging sources for FLA are not well suited for lifepo4. You're likely to burn out your alternator - so get a dc-to-dc charger like a Victron Orion. Assuming you have some solar charging as well. Most 12V converter/chargers just don't work very well for Li - especially if it has an equalization mode, the voltage is way too high.

[eyecando]

I have a 200 ah battery in my 2020 Navion. You should consider insulating the bank if you are going to be in cold weather at or below 35 deg. C. Also verify the BMS will disconnect the bank in cold weather.

Don't forget to change the settings on your converter and solar controller.

Mike