Growatt battery need charging to 100%

felmer

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?

admin

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.