Can one charge the starter battery of a BYD atto3 electric car with the Blue Smart IP22 Charger ?
The charger is designed for 12v batteries so yes.
I have found the ip65 a good choice as you can leave a clippable detachable section permanently attached to the battery and then have the tail easily accessible if this is a regular occurance 
Just a suggestion if you don’t have the ip22 already.