Hi
We just got two 5.2kw batteries installed. In the app on the main page it shows the batteries as being 100% but when I drill down into the batteries the primary one is 98% and the secondary is 95%. Reviewing the historical data they have never charged any higher than these values. Is this to be expected?
Thanks
Yes,
It’s to do with DOD (or the masking thereof)
They will generally run between 15% & 95% which gives you your 80% usable value on your 5.2 batteries (so about 4kWh actual each)
I’m not quite at 100% but inverter shows 97% with both batteries at 95%. When my inverter shows 100% my batteries….like above…don’t show 100%. At most 98%.
Remember the 5.2s are 80% DOD. Your 9.5 is 100% DOD however they aren't really (which is why on a calibration run you can shove more than 9.5kWh in them.)
Like CPU's Silicon Lottery, some battery packs will just be able to hold more than others.
They should in theory be about 232.5AH* or 11.9kWh such that they can be run seamlessly with all the other sized packs (you shouldn't have different battery voltages in parallel which you would get if you ran them to a different DOD to the others)
A since deleted (but it's the internet so nothing is really deleted) Givernergy KB article explains it.
*nobody makes a .5AH cell so either these have obtuse rounding on their labels or it's some sort of Frankenstein cell arrangement or even different DOD which would explain why the BMS is having a real hard time with working out what's actually in it.