Has anyone here actually used LiFePO4 batteries in RV setup?

Hey everyone — quick question for the RV folks here 🙏

Has anyone here actually used LiFePO4 batteries in RV setup? I’m planning an upgrade and deciding between going with one 600Ah battery or two 300Ah batteries in parallel, and I’m a bit stuck on which way is smarter in real-world use.

I’m looking at these two options:
one unit 12V 600Ah battery
two units 12V 300Ah mini size battery (would run two in parallel)

On paper both setups seem workable, but I’d really like to hear from people with hands-on experience — things like reliability, wiring complexity, redundancy, performance, or any regrets after choosing one way over the other.

Any advice or lessons learned would be greatly appreciated. Thanks a lot for your time!

sorry, the two battery links is: https://cmxbattery.com/product/mini-size-12v-300ah-bluetooth-lifepo4-lithium-rv-battery/  and  https://cmxbattery.com/product/12v-600ah-7kwh-deep-cycle-lifepo4-rv-lithium-battery/ thanks again

Hi Jackie.

We full timed for around 4 years and still live in the RV on our property we purchased after the traveling.

LiFePO4 is the type of battery, Lithium Iron Phosphate. There are many sellers, including the one you linked.

We have 1200 watts of solar run series/parallel, MPPT 150 volt 70 amp controller, smart monitor, Qty3-100AH LiFePO4 batteries ran in parallel.

Before this setup, we had a lot of experience with lead acid batteries. We went with LiFePO4 due to the higher lifetime charge cycles and the ability to discharge past 50%.  

We never intended to run a high draw appliance like AC or water heater. We did boondock often and the setup worked for everything we needed. Fans, lights, coffee maker, electric skillet, charging devices, water pump, refrigerator, etc. 300AH was about perfect for the panel wattage and our needs. We never had to charge the batteries with a generator.

What do you currently have as far as batteries and solar and/or what are you hoping to run in the RV with the 600AH?

Jackson Bradley wrote:Hi Jackie.

We full timed for around 4 years and still live in the RV on our property we purchased after the traveling.

LiFePO4 is the type of battery, Lithium Iron Phosphate. There are many sellers, including the one you linked.

We have 1200 watts of solar run series/parallel, MPPT 150 volt 70 amp controller, smart monitor, Qty3-100AH LiFePO4 batteries ran in parallel.

Before this setup, we had a lot of experience with lead acid batteries. We went with LiFePO4 due to the higher lifetime charge cycles and the ability to discharge past 50%.  

We never intended to run a high draw appliance like AC or water heater. We did boondock often and the setup worked for everything we needed. Fans, lights, coffee maker, electric skillet, charging devices, water pump, refrigerator, etc. 300AH was about perfect for the panel wattage and our needs. We never had to charge the batteries with a generator.

What do you currently have as far as batteries and solar and/or what are you hoping to run in the RV with the 600AH?

My main goal is to power my parking AC overnight. I’d like to keep the AC running through the whole night if possible. I also prefer using an electric cooker instead of propane for some of my meals, so my loads can be pretty high at times. Right now I’m trying to decide between two 300Ah batteries in parallel or one 600Ah battery. The 600Ah model I’m looking at is rated at 250A continuous discharge, while the 300Ah version is 200A each , so two in parallel would give me up to about 400A discharge capacity.

What I’m not sure about is real-world usage , whether 250A continuous discharge from a single 600Ah battery is enough for AC startup surge plus cooking loads, or if going with 2×300Ah in parallel is the safer choice. If 250A is sufficient, I’d prefer the single 600Ah unit to keep wiring simpler and cleaner.

Would love to hear your thoughts based on your off-grid experience. 👍

Jackie Lei wrote:
My main goal is to power my parking AC overnight. I’d like to keep the AC running through the whole night if possible. I also prefer using an electric cooker instead of propane for some of my meals, so my loads can be pretty high at times. Right now I’m trying to decide between two 300Ah batteries in parallel or one 600Ah battery. The 600Ah model I’m looking at is rated at 250A continuous discharge, while the 300Ah version is 200A each , so two in parallel would give me up to about 400A discharge capacity.

What I’m not sure about is real-world usage , whether 250A continuous discharge from a single 600Ah battery is enough for AC startup surge plus cooking loads, or if going with 2×300Ah in parallel is the safer choice. If 250A is sufficient, I’d prefer the single 600Ah unit to keep wiring simpler and cleaner.

Would love to hear your thoughts based on your off-grid experience. 👍

There would be a lot of factors in that equation. How often the AC cycles per hours based on ambient temps, what your startup and run amp draw on your AC would be the main ones. We have a soft start on our AC to power it with a 2000 watt generator. We rarely did so but the soft start does help reduce the startup amps a lot.

AC was never a goal of ours to run on solar so I never monitored how many amps it draws and how often it cycles.

I do not have an experience to share in the solar/AC area so hopefully someone else does.

Thanks  very much! this is really helpful insight. I appreciate you sharing the real-world experience, especially the part about duty cycle and soft start impact. That gives me a much clearer way to think about the AC load instead of just looking at rated numbers. Learned something valuable here.

Jackie Lei wrote:Hey everyone — quick question for the RV folks here 🙏

Has anyone here actually used LiFePO4 batteries in RV setup? I’m planning an upgrade and deciding between going with one 600Ah battery or two 300Ah batteries in parallel, and I’m a bit stuck on which way is smarter in real-world use.

I’m looking at these two options:
one unit 12V 600Ah battery
two units 12V 300Ah mini size battery (would run two in parallel)

On paper both setups seem workable, but I’d really like to hear from people with hands-on experience — things like reliability, wiring complexity, redundancy, performance, or any regrets after choosing one way over the other.

Any advice or lessons learned would be greatly appreciated. Thanks a lot for your time!

Have you used a power system of this type at all? 600AH @12V is NOT enough power to run AC overnight. With a total of 600 AH @12V gives you about 5000-6000 useable watt hours and even less if you want maximum life out of them. You need more volume and you really need to consider a better voltage 12v is going to run HOT with those kinds of loads.

Just my $0.02 then again I've been living with or on batteries / solar over 18 years now......

You can go off of the posted manufacturer info and not use a soft start or measure your own AC and figure out what you need from there.

We ended up staying at a few places over the years that had electrical issues. When we first started traveling, we had one of the basic "one time use" surge protectors that plug into the end of your RV cord then into the campground plug. We ended up hardwiring a better quality surge protector in one of the RV compartments. You can replace the surge protection part of this unit rather than replacing the entire thing.

Anyway, one huge benefit I was not even looking for was the bluetooth connectivity/monitoring. You can watch the amp draw on all of your RV systems as they cycle on and run, through the surge protector. This became very beneficial for our particular situation.

If you are planning on investing in a surge protector anyway, you can watch the amp draw on your AC in real time if you get one with the bluetooth monitoring function. There are a lot available at different price points. This would help inform your solar size decisions. But again, you could just use the published info on the unit data tag or look it up.

This is the one we have - https://www.powerwatchdog.com/shop/p/neutral-set-y43ls-4tffr-mcywg-jc38p-z5drg-dh26l-y7yan