• Growatt
  • Growatt battery need charging to 100%

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?

    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.

      2 months later

      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%?

        felmer If you don't toggle on "Adjust charge rate", we basically send the same instruction as you set via the Shinephone app or portal. ¯_(ツ)_/¯