“So if you have solar--turn it off during storage. I don't like that.”
During storage, this point is almost immaterial IF the battery (via open switch) is in electrical isolation during storage, OR with a solar controller that features programmable float voltage and timed absorption cut-off such as BlueSky or comparable. Some controllers also have programmable temp parameters as well.
As for the notion of a ‘30 day rule’ (e.g. for cell-balancing - this, without regard to number of discharge cycles??), to my knowledge no such rule exist…Rather, a consideration of the interactions between the ‘number of discharge-cycles’ count, and ‘depth of discharge’ excursions is in my view a far more realistic strategy - the interactions between the two can contributor (say overtime…) to dreaded cumulative SOC meter drift, and impact the frequency for meter resynchronizations…
As far as paralleled mis-matched LFP battery capacities goes, YES it’s doable but one might consider the following caveats (there may be others…).
1) Under a heavy discharge scenario, once the capacity of the smaller battery lowers enough, the larger capacity will send a portion of it’s current to charge the smaller battery while continuing to satisfy the heavy appliance load - this heavy loading may cause it’s BMS to cut-out.
2) SOC meter accuracy (assuming a common single-shunt and meter) is more likely to undergo meter drift and go astray….This unrecognized current diversion (i.e. waste heat) may necessitate a ‘more frequent’ full recharging regime (resynchronizations, and cell rebalancing) to maintain meter accuracy…Meter wise, determining SOC’s for a LFP is not as straightforward as it is with wet-cell types.
3 tons
