The 12v electrical setup in the Delica campervan took a few weeks to research and finalise, but we are extremely happy with it. Like the bed frame, the electrical system was designed to be effective, simple, easy to assemble, modify and repair if needed. During the the research and design phase Karl sought advice from a number of online automotive forums and also contacted Derek from ABR Sidewinder prior to ordering the necessary equipment. Most connections were soldered where practical. Additionally all connections were crimped and heat-shrunk in order to reduce the chance of losing a connection or short circuits occurring.
In order to make the design, assembly and modification of the 12v electrical system as simple and effective as possible, I decided to create a simple schematic diagram using the Google Layout program. The following schematic shows the core components of our system, as well as the approximate cable thicknesses and lengths, plugs/connections, and other accessories and paraphernalia required.
DISCLAIMER: Use the information provided in this article at your own risk. We are not responsible for any damages incurred to yourself or your property from following this information. This is a representation only of the 12v electrical system we installed in our own Delica camper. Ensure that you always disconnect the ground (black) cable when working with your electrical system. If you are not confident or knowledgeable enough to install and modify electrical system yourself then it is recommended to see your local auto electrician. Be sensible and be safe, always err on the side of caution.
If you are looking to install a 12v electrical system in your campervan as we have, there are some key points to keep in mind as you do your research:
- Safety first: Always disconnect the earth (negative / black cable) when doing any work on your system. Always use correctly rated fuses and/or circuit breakers on all cables to/from any devices and batteries.
- Work out your power consumption and generation requirements: We sought expert advice from our local battery store and ABR Sidewinder to determine what capacity battery and what output solar panel we would need. It was established that as we we were planning to constantly run our 12v ARB fridge, charge two smartphones each day, and charge our notebook PC and tablet for a few hours each week, that we would need an 80Ah deep cycle AGM battery as a minimum. Furthermore, we were recommended to use a 100Ah battery to allow for headroom. We were recommended to get the largest solar panel kit that we could afford and fit inside the vehicle, as a larger wattage solar panel kit will provide more power to charge to battery faster and compensate for low-light conditions where efficiency is reduced or reduced hours of sunlight during winter. We eventually settled on a 120w (2x 60w) portable folding solar panel kit, as it represented the best value at the time compared to larger systems, and was small enough to fit inside the storage cavity underneath the bed.
- Thicker is better when it comes to cables: Many home made 12v dual battery setups neglect using appropriate thickness cables, which represents a potential safety hazard and poor performance. Cable thickness is especially important when the cable is carrying high loads and over longer lengths. As shown in the diagram we were recommended to use 6B&S cable as a minimum for the cables running between the two batteries. Thicker cables are even better, but they are difficult and unwieldy to route and install, so keep that in mind before you go out and buy super-thick, oversize cables. We also used 10m of special 6mm2 thick, tinned solar grade cable to run to the solar panels to avoid voltage drop and other issues.
- Charging from the alternator is worth the effort and expense: Originally we were going to have an independent ‘house’ battery charged only from the soalr panels. This seemed like a good idea at the time, but we soon realised that it wasn’t the most robust and reliable plan as we would be spending many day driving and would be travelling in late autumn and winter, where cloudy days would be common. It cost a bit extra to buy the necessary cable, volt sensitive relay (VSR) / isolator and circuit breakers, but it as well worth the extra expense and time spent to research, design and install.
Primary battery and VSR in the engine bay. I had to make a mount for the VSR on top of the battery and position it in this way to avoid it fouling on the air intake assembly on the underside of the bonnet. Note that the power cable has been relocated so it no longer sits against the coolant expansion tank.
Test installation and power check. All internal components and battery are seen here, including the outlet board, 4-way fuse box, cable for the solar panel and the insulated auto-reset circuit breakers.
After a lot of trial and error, we found that the easiest way to route the thick power cables from the engine bay to the interior of the Delica was to run the cables through the engine bay, under the car along a chassis rail, and then through the existing grommet opening located underneath the passenger seat (remove the passenger seat for easy access). Ensure that you cover all the cable with weather resistant, protective split tubing, use heavy duty, outdoor-grade zip-ties, and also ensure that the grommet opening is sealed with silicon to prevent water coming through from underneath.
Battery and accessories fitted and installed. Shown is the protective plastic battery box (attached to the floor using seatbelt webbing), 4-way fuse box and 12v outlet board screwed to the side of the cabinet, and 10m cable in the storage pouch behind the driver’s seat.
If you have any questions please leave a comment below, or send an email to karl (at) comfortablylost.com.