Picked up the 2016 17.55 Journey Outback poptop,Saturday.Del by owners to Chinderah NSW.Checked breakaway battery when home ,no charge and old.These are charged separately by vehicle.I do not want to leave 240 v on continuosly.Anybody made up a trickle solar charger for the breakaway battery that can be plugged into caravan plug as per vehicle plug.If so did it work ?