Is it possible to have a leisure battery in the trailer that's connected to the one in the van? ie it will charge off the vans split charge/ehu and solar panel and supplement the vans leisure battery?
so if your starter battery is fully charges and you have a leisure battery been used for the weekend what's the difference, one will be flatter than the other, but once you start the split charge joins them.I have looked into this one and it's not a good idea.
When you link X2 bats together they should always be charged and drained in unison or you run into problems.... ie when you connect a 100% full bat to a 60% full bat.
In the end I just shoved a second 110ah battery under the passenger seat.