Battery builder certification

Hi, I'm building batteries for a while.

But as a bike mechanic, my intention is to help customers with dead batteries on reputable brands we used to sell.

Those brands either can't ship batteries to the UK or simply went on burst, sorry Vanmoof :(

I got great result fixing them and building new packs on original BMS and casing, but I wonder if I need or should get some kind of certification to release those fixed batteries to customers?

The idea is to back up my knowledge from industry expert, and give the confidence customer should have when purchasing 500£ batteries.

Also, if things go wrong, insurance companies will surely not cover a shop without electrical certified workers.

So in 2 lines:

• Do I need a certification to repair and rebuild Ebike batteries (generally 36v 20A) as a business ?

• Does such certification exist within the UK (preferably Scotland)?

Thanks for your lights :)