Roughly 3 times a month, our battery plummets in power during the night when there is nothing obvious drawing power. It can go from 80% full down to 19%, or 60% to 20% etc in one fall swoop.
I do not have anything set on the inverter other than to top up battery from 2-5pm to 80% as we are on Octoplus Flux and that is our cheap rate top up.
This dropping of battery power has not just started and we have monitored it, but it obviously needs sorting. Any ideas please? Thank you
G
#2geoffreycoan
glenstriven Plenty of other threads on this phenomenon. It sounds very much like the inverter is loosing track of the state of charge of the battery. You’re not actually loosing that % of battery charge, it was never there but the inverter thought it was.
It’s something GivEnergy are well aware of and they have tried multiple firmware changes to reduce the issue. Upgrading to the latest firmware and BMS versions can help. The best way to avoid it is to use the battery as fully as you can do, letting it fully charge up and letting it fully discharge down to empty, then let it rest empty for an hour or so before recharging again. By fully filling and emptying the battery it lets the BMS recalibrate its idea of what full and empty looks like.
And by the way, if you have decent solar generation its not actually worth it to charge your batteries overnight on Flux as the daily export rate and the overnight import rate are so close together that by the time conversion losses are included you are actually slightly loosing money charging overnight. Yes do charge if the next day solar is poor and you’re not going to have enough in the battery to last through the Flux peak period, but otherwise, no (financial) point to charging overnight
