I've been seeing that when my year old Growatt battery stack reaches 25% charge, under heavy discharge the charge level falls off a cliff very quickly. I opened a case with Growatt support and they took a look. They said that this is because the batteries aren't being charged to 100% and so they battery optimisation process doesn't run properly. This in turn leads to a discrepancy in charge state and why I see the issue (could of course be bull, I'm still waiting for decent solar or couple of days of low Agile import cost to re-test).
When I use WW to charge (Agile auto-scheduling or manual slot scheduling) even when set to 100% charge in the schedule it always comes up a bit short (typically 97-99% charge). This is even when there is sufficient charge window like this morning.
Growatt have said ideally it has to charge to 100% every full charge, or at least once per month. Is this something you can address in WW?
Growatt battery need charging to 100%
felmer Unfortunately, there is nothing we can do about this. It's common for batteries to take longer to reach 100%, due to the reduction in charge rate by the BMS as the SOC gets closer to 100%.
Our instructions whilst automated, use the same underlying Growatt settings.
When Growatt say 100%, they likely mean, charge it to 'full', even though you may not quite reach 100% exactly.
admin
Sorry, bit of a while since I opened this thread, but wanted to follow up as I keep getting optimisation messages from Growatt that the batteries need a full charge to optimise. With WW they only charge to 98%, even if I give WW plenty enough charge slots to get to 100% charge.
If I manually set a charge slot in Growatt App/desktop portal it will charge to a value of 100%.
So is there not some algorithm in WW that is perhaps slowing down charge rate too much when battery is nearly full thus stopping it from getting to 100%?