I’ve noticed a couple of times in the last few days where the battery has been at around 20-25% when I first check in the morning, but then it’ll be at 100% less than an hour after that even though the grid/PV import stats show nowhere near enough to have performed this charge. I’ve tried restarting the inverter but haven’t done anything with the battery yet. Any advice on what could need checking as I don’t think this behaviour is correct?
Kiboomiz Do you regularly fully charge and fully discharge your battery? One hypothesis is that the BMS is rather poor at tracking SoC in the middle range, and needs to regularly visit the extremes to get its bearings. Then after a small change it unexpectedly finds itself at an extreme and is able to report a correct value.
However, not sure that fits in this case, since it's after a prolonged period of discharge that it would suddenly have found itself full. If it was going to jump, it would have seemed more likely that it would unexpectedly find itself empty, rather than full, after discharging.
TBH I’ve left it to its own devices, so haven’t interfered with settings as OVO have generally been doing that. I have tried recalibrating the battery so will see if that sorts it out.
Well recalibrating made no difference, this morning it was at 30% just before 09:00 and then 100% about 15 minutes later!
Can you monitor Battery Voltage? What software / firmware are you on?
My batteries jump to 100% when the voltages reach 57.5 ish.
I guess 30% should be around 52V - how much charge do you add to get to 100% ?
Newman will try monitoring voltage. Firmware versions are - DSP v212, ARM v212 and BMS v3020
Your system SOC does not relate to where I would expect it to be. There may be something else going on so I would suggest monitoring individual cell voltages ( rubik app ?) but the first thing I would do is a calibration. This discharges the battery down to 45V then charges to 58V approx so the system knows where 0% and 100% are respectively. If you set your discharge and charge rates down to say 500W and kick it off at tea time then you may not waste too much power and get the recharge during tomorrows daylight. Good Luck , it takes longer than you expect.
I did a full recalibration over the weekend, and although the first couple of days it shot up to 100% too quickly yesterday and today it’s behaved normally. Will keep monitoring and see if it’s settled down. 🤞🏻
I have no faith in SOC tracking. My 2 x 8.2 batteries (3020) have just jumped from 80% to 100% , the two batteries were upto 40% apart before the voltage hit 57.6 . I know SOC will still be out but it is not essential so I won't calibrate.
Update on this issue - raised a support ticket with GivEnergy and they updated the firmware to v3022 and did another recalibration and that seemed to sort things out as didn't see any strange charging behaviour, so thought that was problem solved.
Then got an email to arrange a site visit, which I wasn't expecting. Engineer has just left after swapping the battery out for a new one, apparently they'd spotted abnormal behaviour in the data that I hadn't noticed and one of the cells had developed a fault. New battery's now been calibrated to hopefully all should be back to normal once that's complete.
Hats off to GivEnergy for proactively dealing with this issue!