How To: Fit a Leisure Battery & Split Charge System
At present, JK offers a couple of simple, easy-to-install split charging systems suitable for Splits and Bays, along with T4, T5 and T6 models.
To illustrate how straight forward the procedure is, we installed one in an Early Bay. You will require a 13mm spanner, a screwdriver, cordless drill, cutters, wire strippers, crimp tool, three suitable self-tapping screws and cable ties. You will also require a battery clamp and a leisure battery. As always, before commencing work, remove the earth (marked negative) lead from your main vehicle battery.
The design of the Bay Window makes it ideal for a leisure battery install as there is a spare tray on the left hand side of the engine bay. From this, lay the wiring loom across the back of the Bus, routing from left to right.
A good place to locate the relay is on the left hand d-post inner structure. Hold it in position and mark the top locating hole.
Drill this and mount the relay using a suitable self-tapping screw.
The wiring loom for the rear lights runs along the top of the inner engine lid hinge panel, held in place with metal tabs. Carefully prise these open and locate the new section of loom within. Alternatively, use cable ties to hold the new loom to the existing wiring.
Remove the positive lead from the main battery and secure the new power lead under the battery clamp nut.
There are just two wires on the split charge relay. The brown wire goes to earth (we utilised the existing tail light earth for this) and the red (positive) wire needs to go to a switched live. For this, we routed the cable under the engine bay tar board and piggy backed it to the switched live terminal on the ignition coil.
With the leisure battery in place, install the auxiliary fuse box loom under the battery clamp nut.
Then locate the fuse box on the rear inner wheel tub.
Next, install the leisure battery earth lead. This must be bolted to a good earth point. On our Early Bay, we found an existing, factory-drilled hole on the inner d-post support and elected to use that. If no such hole exists, use an 8mm drill bit to create one.
Finally, you don’t want your new battery sliding around, so we used a JK universal battery clamp to secure ours in place. Once installed, connect the positive leads on both batteries, then the earths. All should now be up and running, just leaving you to wire any accessories forward from the new fuse box.
Split Charging your Camper!
There’s nothing more frustrating than turning the ignition key at the end of a relaxing holiday or day out, only to hear the stomach-churning click that signals a flat battery. This is usually followed by at least an hours wait for your chosen recovery service to arrive. Not to mention the embarrassment!
Fitting a leisure battery and split-charge relay means you’ll never have that ‘will it / won’t it?’ moment again and can enjoy your time away in your Camper without worry.
In an attempt to make this essential upgrade as simple as possible, we’ve put together a range of easy-to-install kits with pre-made wiring looms, relays and fuse boxes connected. All you need to add is your choice of battery and a battery clamp.