Elektroroller-Forum.de

Sorry for using English.

I went away for 3 week and when I got back, one of my batteries was not working.
I charged the bike overnight but when I press the button on the battery it flashes A8 and then NO
I also noted some cracks in the battery housing. I never take the batteries out so not sure what happened there.

Any ideas?

Here are some photos
https://photos.app.goo.gl/S1Ahtd5mfV2Yk1Vn8

Cracks in the housing are a sign of swollen battery cells inside. You should immediately inform your dealer about this problem and ask what to do next!

You probably still have battery warranty on those?

Thanks, unfortunately the reseller in Malta stopped being a distributor for Kumpan

Then you should directly contact Kumpan Germany to see how to proceed.