I'm a bit confused about the coding of a new battery and whether it's even required at all? Today I changed the battery in my car and took out a failing 95Ah Exide OEM battery and fitted a 100Ah Banner Powerbull Pro. The new battery has a serial number, but no BEM codes.

I kept voltage applied to the battery terminals at all times and I've read on another forum an opinion that doing so means you don't need to code with vcds. So now I'm confused -

- do I need to code the new battery? Car seems happy enough right now and starts up ok without errors in auto scan on vcds
- what does coding actually accomplish?
- I've seen others suggest leaving product number the same but just changing the previous serial by one digit. Is this the best approach?

just wondering whether to take the risk (small as it might be) or making a coding change or whether I just leave it alone on the basis the car is working with the new battery. Thanks all