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valerion avatar image
valerion asked

ESS Optimized causes MPPT to shut down

I had this issue previously with my lead acid bank, and I thought it's the shunt causing the issue. Friday morning I replaced my battery bank with a Blue Nova Li-Ion one, and removed the shunt. The battery side should be managed by the built-in BMS.

I had the batterylife SOC set to 50% overnight, but it didn't charge much during the day, discharging to 50% by sunset, which I found strange. So on Saturday I set the SOC value to 100% to just get the bank fully charged. However, when the battery reached 100%, the MPPT charge controller shut down completely. I get the same with both Optimized settings, with and without Batterylife. If I switch to Keep Batteries Charged the MPPT charge controller provides power to the loads. If I then reduce the SOC back down to 50%, loads are powered from both the battery and the MPPT charge controller, as my yield is much lower at this time. This is likely also what I saw Friday night.

Does anyone have any suggestions I can try, please, to keep powering loads off the MPPT charge controller when the battery is full? Thanks.


I have attached some screenshots over time for Saturday.

VRM at 7:30am

solar-7-30.png

VRM at 9:40am

solar-9-40.png VRM at 13:06 with Optimized enabled

solar-13-06-batterylife.pngVRM at 13:08 with Keep Batteries Charged

solar-13-08-keep-charged.png


ESS
solar-7-30.png (32.5 KiB)
solar-9-40.png (32.4 KiB)
solar-13-06-batterylife.png (30.7 KiB)
solar-13-08-keep-charged.png (30.9 KiB)
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1 Answer
nickdb avatar image
nickdb answered ·

It isn’t wise to set min soc to 100%.

You can see states 1 and 2 active.

To exit these states ess must get above the min soc which cannot happen at 100% soc.

With the battery charged it does not need power to charge, in states 1 and 2 PV is only used to charge and grid for loads. This is how it works so it is behaving right.

Set it to 95% or less and it will work or if you need 100% use keep charged.

You are using ess in a way it was not intended to be used.

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valerion avatar image valerion commented ·
Thanks for that, it now works as I expected.
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