UKH

I realise that there is a bike forum, but that it might not be the best place for a question about e-bikes ?!

The shop I bought my bike from says to plug the charger into the mains first, then plug the chargeur into the battery. The instruction manual states bike first and then into the mains... So my question is which is correct, and why? 

Thanks

Green light & red light on charger brick? Mine did so used to plug mains first and observe green light indicating charger was fine and input power acceptable. Then plug in battery and light turned red to indicate charging. Always had it in my mind that if battery connected first and there was a fault, when plugged into the mains, the battery could be damaged.

Maybe chargers aren’t that smart but this seemed logical to me. It worked fine doing either way to be honest though, it’s just in case of a fault with the charging brick, small chance admittedly 

Chargeur? Is it French?

Without knowing anything about your bike it's impossible to say for sure, but I would always trust the manufacturers instruction manual over someone who just works in a shop.

As to why... I'd need to look at the charging circuit to work that out. There are possible reasons for either case. But any system for end users to charge e-bikes would surely be designed to cope with either connection order, it would be crazy not to.

Well that makes perfect sense. Thanks.

Whoops, yes it is French ! Yes I agree with making more sense to make it work both ways. Wilkie has a point though.

If the power supply comes up slowly, or worse, wobbles, it can stop a processor getting a proper reset.  So usually best to connect mains first.

Thanks.

But some charge management systems will want to have the battery connected before the power supply. It all depends on how it's been designed. As we don't know this, I would suggest RTFM is the best option.