lithium question

BFL13 wrote:

pianotuna wrote:
BFL13,

Given that SiO2 can do 4C continuously, and can be taken to 0% state of charge, why would you suggest that it takes 2 SiO2 to equal 1 LiFePo4?

Didn't mean to say that, if I did. You can use the one LFP or SiO2 with its own inverter to run the MW etc, and use the existing FLA bank for the rest.

100AH is just not enough of any kind of battery bank for a weekend off-grid in the winter. If you don't have the FLA bank you need two LFPs (no mixing--second must also be LFP) or two SiO2s ( might get away with mixing types with them, but not for me thanks) to run it all.

Two FLAs can't run the MW like one of those others can with its high discharge rating, and you still need lots of AH for normal furnace running etc, so that means two of the expensive ones to get just 200AH.

Weight is an issue for these guys with small RVs or they could just have four 6s. That means LFP for the single MW one.

Yep. Weight is definitely an issue for us. But for two reasons. The batteries are located under the bed and slightly behind the axle. The hitch actually gets lighter as you add batteries. Not on a one to one ratio, but it does get lighter. I like to keep the trailer hitch weight at around 10 percent or more on any trailer I’m towing. Nice thing about little trailers is you can literally use a “large person” bathroom scale to accurately measure it. :). Anyway. Adding another set of 6 volt AGM’s wouldn’t be an option for us. If we need more capacity it’s either

1. More solar (but we like to park in the shade so......)
2. A small propane generator to charge the 6 volts once per day for 45 minutes (prefer not doing this but maybe).
3. Switching to a set of LFP 100’s Pricey but doable and the cabinet is ready for them.

Once we start camping in the spring we’ll figure it out. Can’t wait.