Found this, might help
On our Chausson Welcome 35, the Ford fitted Auxillary
battery is in parallel with the rest of our 'leisure' (actually traction) batteries.
The 'starter only'
battery is isolated by a large relay on the Ford
battery compartment
fuse board.
This, in effect is your split charge relay and energises when the ignition is switched on.
The bonus with this setup is that your radio and vehicle road lighting run from your leisure
battery bank if you engine isn't running.
The Chausson-fitted 'split charge relay' simply isolates your auxillary/leisure
battery bank from your caravan electrics, nothing else! This is energised by your switch on the control panel over the door.
You will note the Chausson-fitted relay mentioned above and leisure
battery are connected to one of the three 'customer connections' fitted on the left rear of the driver's seat/
battery box. On your model, the relay might be connected directly to your leisure
battery (the effect is the same).
These are all fused at 60 amps each. And will supply charging current when your engine is running.
If you fit extra batteries, just connect your positive lead to a spare one of these.
Use a heavy duty cable to help with voltage drop if your new batteries are a distance from these connections.
Doing this works fine on our MH, no issues to date and three days,below zero, off hookup with our Webasto Dualtop going 24 hours/day.
We aren't sure when the Ford
battery will expire, but don't expect it to last forever with continual deep discharges!!!!
Hope this helps!
