even when my aggregate charge has been "full" on SOC the underlying has been nowhere near - and stopped charging.
Primary 99%
Batt1 83%
Batt2 81%

There is no consistency. At times Primary has had the highest charge but at times Primary has been the lowest!

It seems to me there is definitely an issue - as its being raised by a few people. Other people may have the problem but simply be unaware if they are not monitoring.

The lack of responses from @Givenergy is disappointing - indeed worrying.

As Octopus Tracker is cheap today (19.56p) I will kick off a full charge. lets see where it gets to

@tim441, I'll contact GivEnergy and see if they can assist you.

@tim441, just heard back from GivEnergy. They've suggested that you call their call centre and they'll walk you through everything: 01377 252874.

Let us know what the outcome is. 

@editor thank you very much for taking the trouble. Apologies for slow response as I've been travelling today. I will follow up tomorrow & let you know what they say.

From other discussions it seems this problem has been ongoing for some time & with quite a few people. I suspect some people with 2 or more batteries may not be aware of the problem as it does not trigger any alert. It's seen only by drilling down in app or data etc.

The hope seems to be with a firmware update that's being tested... to solve this and other problems. No release date known.

But I'll try to get a fuller update tomorrow.

Thanks again. 

@editor Givenergy have agreed to send an engineer. Not clear if that's to run tests/checks or what has been diagnosed. But will be glad to see them and hopefully get matters resolved so we can maximise usage of the batteries going forward. Thanks for your help. Will update with news.

I'm keen to see a solution as I have recommended Givenergy to quite a few people and hope that they live up to general good impression of good value for decent quality. I have an additional solar project later this year - planning to add battery (or 2 ) and EPS ..... and so far think that will be Givenergy.

Hi

I install these batteries as well as having a system with two 9.5kWh packs. 

there is an ongoing issue with SOC drop off and I expect this is causing imbalance in your stack. 

if one of the BMS modules reports incorrectly, it will not charge or discharge depending on which way it’s wrong. 

there is an update being tested and is a couple of versions in, one of my clients is a test system. 

it’s very frustrating as there seems to be no real prioritisation from GivEnergy on this point  

whilst I certainly don’t have inside information, the feeling is their focus is on the new EV Charger and All In One product releases as well as the European market expansion.

Hopefully once the new products are released we will see some focus on resourcing this existing problem. 

Knowledgeable & helpful Givenergy engineer visit today as arranged. From the log data he was sent as they thought there might be a faulty cell in one battery. Partly based on the voltage data that he said gave more reliable information than SOC. Sounded feasible?

However when stripping down offending battery discovered several connections were not tight by 2 or 3 full turns. Obviously not good! Cleaned up and remade connections. Checked other batteries (which were fine). Started a calibration.

I will monitor in coming days. His view was that the firmware update may not make a difference but will apply it once released.

In passing worth noting that the Givenergy "All in one" inverter & battery is likely to be released around end May - similar to Tesla Powerwall

13.5kwh battery
6kw nominal AC output
7.2kw peak power

with additional Gateway to provide whole house backup and 18.4kw nominal AC power

Firmware updated yesterday and calibration completed. Early results look encouraging.

small observation this morning:
SOC 72% 52.5v 23c
Primary 68% 52.8v 25.1c
Batt1 72% 53.2v 24.1c
Batt2 72% 52.7v 23.5c

perhaps this differential between the 3 packs is normal. I will keep an eye on it over coming days to see how it looks at various levels of charge/discharge. But overall looks better than before anyway