Still using grid despite charge in battery!

[JohnH]

Hi, reposting about this issue which has been read 499 times but without any answers!

Currently have 22% battery (minSOC set at 20%) and the grid is supplying the entire house load of c. 400w. I've watched my smart meter and this is not just a brief burst of grid power as the battery ramps up.

Any advice gratefully received!

[reef]

Does it start supplying again if the min SOC is changed to a lower value (e.g 15%)?

I often found in the past when min SOC was set at 10% it still stopped at 11 or 12%. I've since updated to newer firmware and it goes down to 10% as expected now.

[JohnH]

Thanks, I'll try a lower min SOC setting (not sure why it was set at 20% to start with). However the issue seems to be intermittent and I've seen the same thing happening at 28% charge and even 50%.

Not sure I know how to update the firmware or is this something the installer should/could do?

[Dave Foster]

What is the temperature when this happens ?.

If the batteries are in a very cold place they will also do this, when close to 0C you sometimes see the BMS trickle charge them to keep them warm (if they drop below 0C they cannot charge), and sometimes you may see the grid being used because the discharge current has been throttled because of temperature.

As soon as temperatures recover they will work properly, many people build a simple insulated container around the batteries over winter.

[JohnH]

Thanks but the temperature in the garage yesterday was about 10 degrees so I don't think that was the issue.

However when it was cold I saw another odd thing (see pic from 19th) with frequent bursts of c. 600w and I can't isolate where this draw was coming from - there is nothing in the property that would need this as far as I can see.

[calum]

The batteries have a significant amount of thermal mass, given how cold it's been recently, it may take them a little while to warm up - and even 10C isn't *that* warm for these things. They like to be at 20-30C to perform at their best. If they're in a space (garage etc) where they will be at close to external ambient temperature, an insulated enclosure is a really good idea to keep things working right in cold weather.

[Dave Foster]

Just to add to what @Calum said, the 600W is likely to be the BMS maintenance charge trying to hold the charge and warm the batteries.