Our previous van had a Sargent EC155 system that I always struggled with how it charged the leisure battery, and supposedly the vehicle battery but it never did, and what it told about the battery state so for this van I decided to keep it simple. I did the core installation myself and Mirko connected the equipment as he installed it.
We specified the van with the Second Battery which is an AGM battery fitted under the left hand passenger seat. The benefit of specifying this is that the split charge is taken care of in the canbus system – something that is all the more important with a Bluemotion EU6 smart alternator. It also provides the wiring to the leisure battery.
Unfortunately the OE second battery is a piddly 75/85Ah so it had to go and was replaced by a 110Ah item. The OE battery fits on a nice shaped tray in the base of the seat and of course the tray is the wrong size for the bigger battery so a, bit of fettling with the angle grinder was called for. Anyway we now have a 110Ah AGM battery to power the rear / leisure area of the van.
Mains hook up is through a 16A Commando plug (not socket) with a cover mounted under the bonnet. Using Arctic (blue) flex to through the plenum, into the cab and through the floor channel to below the drivers seat. On a panel in the drivers seat base there is a consumer unit with RCD and breakers one of which supplies 3 13A sockets and the other a Victron 12/10 smart charger itself connected to the leisure battery. The consumer unit RCD and breakers are all double pole and it has a red indicator for incorrect polarity. On the roof there is a 100W low profile solar panel connected to the leisure battery through a Victron MPPT 75/10 controller.
In the driver seat base there is a 12V fuse box for the leisure equipment and lighting in the rear. It is also home to the relays for the roof and the dimmer module for the lights. Also in the passenger seat base there is a second small fuse box to protect a few equipment connections. The leisure electrics are controlled by 3 master switches, Carling Concentra with LED markers and indicators, mounted on a panel on the rear right quarter that operate the lights, water pump and hob. Alongside them is a Merlin Smartgauge to monitor the leisure battery. At the same time both the Victron units are bluetooth enabled so the state of charge and the batteries can be viewed through other of these on our iPhones and iPads.
Lighting is all Hafele LOOX LED with a 4 channel remote. We used cool white LEDs rather than the natural ones that look a bit yellow so the brightness can be a bit stark. But with the dimmer this can be softened and several lights spread the light. WE also have a plug in LED strip for the awning. Also around the rear are 3 x 230V 13A, 3 x 12V 10A Hela type power sockets and 1 x 2way USB socket.
The whole leisure / camper system is powered only from the leisure battery / mains hook up / solar panel so it can never flatten the starter battery. If we ever flatten the leisure battery, and the Smartgauge will warn against this, then we can always start the engine and have alternator power to the leisure side. We also adapted the power supply to the ICE/Nav he’d unit so now it is powered from the leisure battery and prolonged use won’t give us a problem starting, we have been caught out with that before. We have added a switch so that it can also be switched on independently of the ignition otherwise it works normally with the ignition.
For the record I got a lot of good advice and much of the hardware from Martin @ Travlevolts.com. What he doesn’t know about motorhome and in particular VWT4/5/6 electrical isn’t worth knowing.