Help with understanding temp throttling please

Hi, I'm reasonably well versed with the GE system and how to run it etc but still not totally sure about the recent battery charge throttling based on temperature. In the app I see a single temp per battery whereas in the Rubikcube Android app I see 4 additional temps per battery. I suspect the single temp is the BMS and the four in the app are cell temps or averages thereof? What are they measuring please and which governs the temp related charge throttling?

We have two 9.5s in an integrated garage, not heated but well insulated and currently sat at about 15 degs. Even with temps below 20 Deg on all sensors, we haven't seen any charge throttling fortunately. Is that because we have two batteries? We're on 3.17. Cheers.

The 4 temps, are the 4 cluster of 4 cells each, which will determine the charge rate..

wrighar Thanks for that. At the moment we're sat around 15 deg on the banks of cells and just over 20 on the BMS. Last night the batteries both charged at full rate where the cell banks were around 16-17 - I thought they might throttle but no. Does two batteries charging in parallel help?

not that it matters (as it ultimately does the same thing) but there's some extra temperatures the BMS now calculates in two registers - min and max cell temp - so the throttling boundary may well be running off those rather than averaging out the 4 cells at the inverter end.
<pointless trivia ends>

hoggy Thanks for that, interesting stuff. So is it fair to say that there isn't any clear information on exactly how it's working? I see folk reporting throttling but at lower temps than the 16-17 we tend to start off at. Although I was under the impression that it started sub 20 deg. Be useful if GE could confirm. Cheers.

sponev it's related to battery size - if you have more than 1 "medium sized" pack then you'll probably not see it throttle as even running at lower charge rates individually, it's still high enough to saturate the inverter.
If you've got a single 9.5 pack then they seem to drop to 2.7kW (surprise! Your back to Gen 1)
If you've a single 5.2 they drop to 1.6ish.

Note: Gen 1 on old FW doesn't care at all about temps so just goes full send no matter what.
I hope it stops charging at 0'C but my garage has yet to get that cold.

GE were asked multiple times what the official limits were but never responded - this is just from what people are experiencing.

hoggy Many thanks, best explanation I've seen so far. So we're fortunate that the double battery set-up appears to avoid the unexpected change Giv rolled out. I can understand the frustration elsewhere however!

As you have 2 9.5's, each will be throttled to 2.7kWh each below 20c, so 5.4kWh in total.

This is still more than the 3.6kWh the inverter can supply to batteries, so you see no drop.

1 9.5 above 20C will be a 0.5C charge rate (about 5.4kWh), limited by inverter to 3.6kWh
1 9.5 below 20C will be a 0.25C charge rate (about 2.7kWh).

extra batteries will add extra charge capacity

2 9.5 above 20C will be a 0.5C charge rate (about 10.8kWh), limited by inverter to 3.6kWh
2 9.5 below 20C will be a 0.25C charge rate (about 5.4kWh), still limited by inverter to 3.6kWh.

wrighar Got it, many thanks!