backchannel: boondocking with LFP

from this reddit post:

Bought a used travel trailer… stock lead acid batteries were garbage

To be fair, deep cycle lead banks can do a good job. Most of them inherited used have aged out and/or not been charged properly.

300Ah gives us 3.8kWh usable

I’d say ~3.1Wh usable if we stick to the 80% depth of discharge spec many LFP manufacturer’s state in cycle ratings. Doesn’t make a practical difference in your case if you’re only cycling 30% of capacity.

The self-heating was a lifesaver.

Warming LFP cells is important in the cold ; internal self-heating isn’t. IOW, it doesn’t matter to the cells where the heat is coming from.

Battery kicks on the heating element automatically and by morning its warm enough to accept charge from our solar panels.

Close. When cells are cold the power from the panels turns on the heating circuit. When the cells are warmed above freezing power is sent back to charging. See the chart in Section 8 of the manual (pdf).

If youre new to boondocking like us dont wait on the battery upgrade. We wasted two weeks and a lot of gas figuring that out the hard way.

I’d encourage folks to assess their actual energy needs before upgrading to LFP. It can help size the new bank appropriately.

Note: the 30% DoD and 3 day autonomy suggests OP bought about 2x the battery bank they actually need.