Question House batteries

[lostinfla]

Currently have the 8 flooded batteries and was wondering, when it's time to replace, if I should go with lithium or just agm batteries. (No solar) We seldom boondock, but were stuck without power for a few days from the hurricane in SC, so I'm starting to think ahead. I have the magnum panel with SOC display but not sure it's compatible with lithium. Also, with lithium, I assume they are all 12v?

 

[AbdRahim]

Depends on how much power you want and how much you want to spend. I had 6 six volt agms. One bad one pulled down the rest. Coulld barely get through the night with nothing on. I went with 3 Li 330AH batteries. I now lose about 1/2 % per hour under the same conditions. That is about 4 days to reach 50%. Hopefully, next year I can get the bigger inverter and be able to run the A/C on batteries. Wish I had room for one more. It should survive the paint shoo without going dead.

If you get agms, I would load test each battery before you drive off. All mine looked good on the volt meter, but, when I finally bought a load tester, found one battery’s voltage went to dead zero under load.

 

[lostinfla]

What brand lithium did you end up with?

 

[Neal]

That is about 4 days to reach 50%

Keep in mind with LiFePO4 batteries the "50%" rule does not apply. You can take the batteries down closer to 10%, which is your bottom limit. Per SES you should cycle them monthly, I run mine down to about 20% the beginning of each month.

I am all in on Lithium (LiFePO4) both in RV and plane. Can't think of using anything else this day and beyond. Great batteries and prices have really come down. If you don't want to do the job yourself I highly recommend Solar Energy Systems in Nappanee. I'm not affiliated! Not only great work but great support as you learn the new system. It can be as simple as just batteries or you can get a more complete upgrade with components that work better with LiFePO4 batteries.

I'm a big fan of Victron but if doing it myself I'd consider the SOK brand. You have things to consider such as internal BMS vs. external, i.e. what is controlling the batteries for voltage and temp protections.

With your conversion @lostinfla from FLA you'll probably want to cleanup the mess those make but you'll also need (want) to seal up that compartment for Lithium's so there is more involved to consider.

 

[Neal]

One item to add for consideration. LiFePO4 batteries cost more but they last 2X as long if not more than lead batteries (FLA and/or AGM). You'll find warranties on batteries typically in the 10+ year realm. Victron is 5 years.

 

[lostinfla]

Anybody thinking of, or in the process of converting to lithium (without solar) please chime in.