Non-working 2nd battery: Gen1 5.2 + Gen3 5.2

This is my set up:
Storage Inverter Givenergy AC3.0
Battery 1 Givenergy Gen1 5.2
Battery 2 added later Givenergy Gen3 5.2
Also a MyEnergi Zappi EV charger

With first battery everything worked fine. After adding the second battery it has failed twice. Sometimes the LEDs are dead, other times all red. The installer had to wait ages to get Givenergy support the first time it failed. He came back, checked connections, charged up the second battery from an external power pack, then it worked for a few days and failed again. Still waiting for a fix after 3 weeks. Gen1 battery still works fine.

My question is this - Is it problematic to mix Gen1 and Gen3 batteries? Should I replace the Gen1 battery with a Gen3? Or is it a duff Gen3 battery I’ve got?
Anyone else had a similar experience?

Thanks in advance.

Paul

What firmware are you running on your old 5.2 battery, according to the release notes there have been fixes related to mixed battery capacities in later BMS’s.

And also, is your new 5.2 attached at the first battery that is connected to the inverter, or did your installer connect it after your existing 5.2?
The reason I ask is the old 5.2 (I have one) is 80% depth of discharge so is really only a 4.2kWh battery whereas the new one is 100% DoD (and I think its 5.12kWh but might be wrong). GivEnergy say the largest battery should be first in any battery chain

Thanks for that info. I will pass this on to the installer. I don’t know the answer to the firmware question, but I will find out. As for the connection order, Gen1 battery is connected first so swapping them around might be part of the solution.

You should be able to see the firmware version and if there is an upgrade in the givenergy portal

Battery firmware version 3020/4004

BMS 3022 is the latest Gen 1/2 battery firmware https://givenergy.co.uk/firmware-revisions/g1-g2/

4009 is the latest Gen 3 battery firmware G3 firmware revisions | GivEnergy

And the latest AC coupled firmware from about a month ago is A214 AC coupled firmware revisions | GivEnergy

I would start off with getting everything upgraded, GivEnergy support will want that doing first

There’s videos on the site above for how to self-install if the portal doesn’t offer you the option

Thanks again Geoffrey. I will pass this on to the installers and check the videos myself.

The gen 3, no matter the size, has to be first i believe.

Thanks, noted.

you can swap the battery cabling around yourself if you want, turn the batteries off, and the inverter, then unplug and swap them round. The orange plugs are a bit of a pig to get off as they have a locking mechanism to stop coming out, requiring pressing in several places at once, but they just plug in and out

Thanks, but I’m going to leave this to the installer who’s agreed to come to sort this out mid-week.