2nd Battery in hung state after latest firmware update

System 3kW Inverter 2 X 8.2 kW batteries.
1st battery and inverter in place nearly a year, 2nd battery installed 6 months ago all working perfect since day one.
Installed Battery firmware last Friday PM after running capacity down
Firmware installed ok but noticed during calibration that second battery had gone offline, was in a hung state and cannot even be power cycled. Calibration finished but now only sees 8.2 kW capacity instead of 16.4
Contacted GivEnergy several times, they cannot resolve remotely and have finally accepted that they need to visit site (Suspect BMS issue) but this is the thing, I am expected to wait 4 weeks at the earliest for an engineer visit on a system within its first year. Currently therefore throwing solar into the grid once 1st battery is full. Sort of defeats the reason for batteries.
Anyone else having this issue, I see from the threads that there are other problems related to this upgrade?

I can't tell from your comments, but has the firmware upgraded on the second battery and have you tried a manual upgrade of the battery software?
I had exactly the same problem, caused by the firmware upgrade failing on the second battery but GivEnergy sent me the files and instructions, I copied the files to the USB stick, popped it back into the battery, which beeped at me and upgraded the firmware. I then had to contact GivEnergy to get them to kick off another calibration but I've regained about 20% capacity and everything seems much more efficient now.

Do not believe that the second battery received the updated firmware, since the upgrade the second battery is stuck in a hung state, I have an amber status light and if I press and hold the side on/off switch it fails to power off and doesn't even beep. I power cycled the inverter and primary battery in the hope that this would have an effect on the 2nd battery but this achieved nothing at all.

When my update failed, Paul at GE sent me the file and this info.
Have you done both batteries

_Remove Slave battery cover, 4mm allen key needed

Remove the USB stick, silver key

Place in a laptop, windows preferred

If not empty, delete everything and check for errors.

Place the file inside the attached zip BMS_ARM.bin on the USB drive and eject it.

Place the USB back in the battery and it will with a bit of luck, flash red/green a few times and reboot.

Repeat for the Master

Reference at https://kb.givenergy.cloud/article.php?id=72

You will need calibration set off manually. Let me know and Ill start it_

SteveCook You will need calibration set off manually. Let me know and Ill start it

he means contact givenergy know as only they can do it.

Have been contacted by GivEnergy today, they are sending an engineer to site next Thursday so hopefully all will be resolved then?
Thanks for the input

Update following engineer visit, Martin (I think) engineer from Giv attended, replaced BMS but new BMS corrupted immediately, traced problem to a corrupt USB firmware dongle which probably occurred during the Firmware upgrade, this then in turn corrupted the BMS.
Replaced BMS again with a clean USB dongle and kicked of the drain down and calibration which looks to have completed successfully so now have full 16.4kW available.
Shout out for Martin who did a great job with me asking so many questions all the time!!