Power

The van runs on 12 V. Two solar arrays on the roof charge one lithium battery under the counter, and an inverter covers the few things that need mains power. Everything reports over Bluetooth, which is what the van hub reads.

What’s in it now

• Solar: 200 W at the back of the roof on a Victron SmartSolar MPPT 100/30, and 320 W at the front on a SmartSolar MPPT 75/15.
• Battery: a Renogy RBT200LFP12-BT, 12 V and 200 Ah of LiFePO4 (2.56 kWh), with a Bluetooth BMS that reports each cell.
• Monitor: a Victron SmartShunt (500 A) on the negative side, for state of charge and time left.

Where it started

My first wiring plan, from July 2019, had two 175 W panels on one charger, two 12 V batteries, a 1500 W inverter, and alternator charging through an automatic charging relay. A fuse block fed the lights, fan, fridge, water pump and 12 V outlets. The system has grown since: more solar, a lithium battery, and Victron gear that reports over Bluetooth.

The wiring diagram

This is the system as it is now, drawn as a proper wiring diagram: every device has a reference, every wire a number, and the second sheet lists each wire’s ends and gauge, each fuse, and what the van hub reads over Bluetooth. It’s drawn with every negative on a bus on the load side of the shunt, so the shunt sees all the current.

Where I haven’t confirmed something, the sheet says so. The gauges and fuse sizes come from the 2019 plan and are marked to be checked, and four things are still open: whether the inverter is 2000 W or 1500 W, whether the alternator charges the battery through the old automatic charging relay or a DC-DC charger, which fridge it is, and the AC unit.

The MaxxFan’s controller has its own wiring diagram, MFB-002, on its build page. Where everything sits in the battery bay is on the van’s drawings (VAN-006).

A second battery

The next thing I’m looking at is doubling the battery. I checked three places for a second RBT200LFP12-BT in the model: the passenger cabinet, the rear garage, and the counter bay next to the first one. The best fit is in the counter bay. The new battery (522 x 240 x 219 mm, 27.3 kg) stands upright 40 mm from the old one, under the sink, whose basin leaves 498 mm clear above it. The two can share a pair of equal-length cables about 0.5 m long.