Battery losing 40% of power in a few minutes

Greetings all,
I have two 8.2 kWh batteries. In October I reverted to charging them up overnight as solar generation no longer enough.

I have noticed a couple of problems.

1. The charge overnight added to the batteries to get to fully charged appears to be less than would be needed. IE 29% full becomes fully charged 95% with only adding 8kwh i.e. just 50% of the capacity.

2. Looking at the battery usage over 24 hours, it can drop 40% suddenly in minutes or add the same capacity suddenly hours later. The system is 2 1/2 years old.
   Any suggestions as to what might be going on.
   Rob Edwards

Cmtere these are both symptoms of the difficulty the system seem to have in tracking battery SoC accurately. Having two batteries might compound the problem - I can't really comment on that.
The recommendation tends to be to ensure that the batteries are allowed to fully charge and to fully discharge from time to time. This allows the BMS to reset its tracking. There's a video on the GE YouTube channel to this effect, though it doesn't really go into much detail of why it's a good idea. In fact I think it falls short of recommending it, merely suggesting that maybe it's a good idea.
Perhaps also allow the batteries to sit idle at low charge for an hour or two, to allow cell balancing. (Not sure if balancing also happens at the top end?)

Are your two batteries maintaining roughly same SoC as each other?

Cmtere DD
I have two 8.2 kWh batteries daisy chained to an AC3.0 inverter.
I got the first battery in August 2022 and the 2nd in April 2023.
In October 2022, my single battery experienced two of these rapid losses with SOC plummeting to near zero.
In Dec 2023, I experienced the same from the two batteries.
There were many similar comments on forums and a big fuss in autumn 2022, with GE contacting many of us to apologise and explain.

Each time I experienced a rapid drop in SOC, I contacted GE.

Over this time my firmware (both inverter and battery) has been updated.
I am current running D0.205-A0.205 (inverter) and 3017 (battery). Previously, I think my battery had been on 3012 and 3007/3005?
Since running the latest firmware for my set up, I haven't had a problem (🤞) and the whole setup has run noticeably quicker.
Certainly check which firmware you are running and ask GE about why you are having these issues. You could also request your system to be upgraded.

Rob

My AC3.0 and 9.5Kw battery are experiencing what sounds like the same issue. This originally coincided with the message "BMS Under Voltage" being reported. When i reported this to givenergy, i was told it was a known issue but have no ETA for a fix.

Now months later I'm getting the same issue without the error being reported. Its now happening every 1 or 2 weeks with the battery dropping from 60 to 4% over 30 mins. I emailed them last week and followed up today but received no reply.

my "assumption" is a firmware update removed the message but did not fix the underlying issue.

Invertor: D0.205-A0.205
Battery: 3017

Tell your installer it is faulty and you want it fixed under warranty. They may exert a bit more pressure?
Can you try an RMA

rblog this seems to be what’s happening with my system. I have a 9.5kw battery which suddenly now only seems to give or take half of that capacity and the charge levels are all over the place. It’s only been in for 8/9 months and I’m really regretting installing this system now. Even simple things like setting a charge schedule is over complicated (for someone with a limited tech understanding!).

I’ve been asking for help for 3 weeks from support and never even had an acknowledgement so I’m going to call citizens advice next week and see what I can do next as they clearly aren’t interested in honoring their warranty.

Sorry for the rant, I’m just extremely frustrated with the whole system!

https://community.givenergy.cloud/d/5267-support

pse2024 initially at least, your contract is with your installer, as the supplier of the kit. I'm not sure how long that period lasts, but I think you first reported problems here in June, which wouldn't be long after the first install.

Do you use Android? There's a free 3rd party app which can help show the health of the battery. I'm on my mobile so can't give a reference, but it's something like inverter monitor on the play store.

I assume at this time of year it has spent some time empty. A slow full charge back up to 100% might be helpful.

Have you updated firmware recently? That used to trigger a calibration cycle, though the newest ones don't seem to bother

My 1st PVs and inverter 2020 are SolarEdge.
When I wanted more panels, inverter and battery in 2022 the installer was very pro GivEnergy because he was an "approved installer" for them and GivEnergy kit was considerably cheaper than competitors stuff - meaning it was more likely he would get me to proceed.
So far for 2 years all has been reasonably OK , but I am a retired engineer and can deal with a lot of niggles myself (firmware update by taking front cover off battery and using USB port, wi fi issues, RCD trips etc).
When I asked about another 9.5 battery he was very keen to steer me to a different solution using other suppliers than GivEnergy. He did not say why, but clearly his appetite for GivEnergy has waned.

SteveCook clearly his appetite for GivEnergy has waned.

He's not the only one. Our installers no longer install GE due to awful battery reliability/operation. That in turn means the house builders who own the installers have taken GE off their approved list.

Hiya,

GE support did come back a few days after my second email. They first upgrade the battery firmware 3018 and re-calibration it. This is on my AC3.0 and 9.5kw battery. Its early days but has operated nicely since. Considering pre upgrade the battery had dropped to 4% a couple of times due to its problems, i was surprised it needed re-calibrating.
After the initial delay, GE was responsive and friendly.

My installer is a Givenergy platinum installer and has stopped advertising GE equipment. I don't know why.