Hi
@Longs11
There's a few questions that spring to mind so I can't really give you a definitive answer, but perhaps by asking questions I can help you tune in your solution.
First question is, is your leisure battery GEL, Lead Acid, or Lithium? Not all chargers can cope with all types of battery etc.
Normally the EHU (electric hook up) goes into a 240v consumer unit, and from there it feeds into the battery charger. The battery charger then goes either directly to the battery or to the battery via the 12v (24v) consumer unit.
You may need to take into account how your start (crank) battery is charging your leisure battery, Is it Split Charge Relay? or Battery 2 Battery (DC to DC) unit? And again your options will depend on type of leisure battery. A split charge relay could damage a lithium battery.
The final consideration is to ask "Do you want the EHU driven charger to charge your start battery too?"
In which case if you've got a DC to DC charger in place you could just charge the starter battery and (depending on if there's a need for ignition to be on or not) the crank battery when charged up will then be charging your leisure battery.
I've seen it done several different ways and I'm sure there are some much wiser people on here than me so I look forward to seeing what others say.
These are just my thoughts.
PS. you could also just plug a charger into your 240v socket and charge the leisure or crank battery, which I've seen done too.
