Day Van Power System Design

A straight forward Renogy Lithium power setup which is perfect for compact day vans like Ford Transit Custom, VW Transporter, and Renault Trafic.

Full specifications and cable sizing can be found at the end of this article.

"Disclaimer: Installing electrical equipment in a campervan requires technical know-how and an understanding of automotive electrical systems. Improper installation may pose risks such as electrical hazards, fire, damage to the vehicle and personal injury. It is recommended to seek guidance from a professional or thoroughly educate yourself before proceeding with any electrical modifications or installations."

The diagram above illustrates a simplistic yet efficient power system, ideal for a day or weekend van setup. Despite the initial impression of the 50Ah battery appearing inadequate, it actually delivers more usable power in comparison to the commonly installed 100Ah AGM battery (Lithium Vs. AGM). Selecting a power system for your van requires thoughtful consideration of its intended use. Overspecification of systems can lead to unnecessary costs, therefore, estimating your typical van usage is crucial to avoid expenses beyond your budget.

This design does not include a solar input or a mains hook-up. Nevertheless, these features can be easily integrated during the initial build or retrofitted at a later stage to accommodate any evolutions in van usage. Consider adding a mains hook-up if you intend to stay at a campsite without driving the van for the duration of your trip. Alternatively, if you plan to spend time off-grid without driving, the addition of a solar panel would be beneficial. 

The Renogy 50Ah battery lacks Bluetooth connectivity or an output for connection to a monitoring system. To monitor your system, a shunt is necessary. If you plan to use the van for extended periods, it might be beneficial to install a shunt, if not you may find yourself worrying about the battery's remaining power.

The total cost (including cables) is £375 (as of October 2023). Installing this system should be achievable within a day depending on the layout of your van. If you're not confident about installing it yourself we'd be glad to discuss how we could help and offer a quote.

Please note, Brento doesn't have an affiliation with any of the companies listed below. However, based on our experience, they offer great products at competitive prices.

To install this system you will need a range of basic tools, and equipment. Having a mix of crimps, terminals, and heat shrink tubing is useful. The list below should provide more than enough consumable items, by planning carefully, you could save money by purchasing specific items separately. Yet, having a variety of parts available ensures the job runs without any delays.

If you haven't worked with automotive electrics before, you might not have the necessary tools for the job. Here are some essential tools vital for a safe and effective installation.

If you'd like to install this system yourself, please read the following notes. It might be possible to reduce cable sizes; however, the current sizes allow it to be installed in any sized van with minimal voltage drop. Sizes have also been standardised to reduce the number of different cables required during the installation.

1. All battery/DC-DC cables are to be PVC high flex battery cable 8AWG/10mm2

2. All appliances should be locally grounded to the chassis or vehicle structure

3. The lighting, water pump and USB can be supplied from a common power supply however individual supplies provide redundancy in the system, preventing a total power loss due to a single fault.

4. Diesel heaters should be connected directly to the battery without an isolation switch. Isolating the power supply of a diesel heater during operation may cause irreparable damage to the device.                                                                           

Appliances -

Fridge - Fridges are sold with suitable cables and fuses. Follow manufacturer guidance if this cable needs to be extended.
USB Outlet - 3A Fuse and 17AWG/1.00mm2 cable
Lights - For a small van 3 x 1W spot lights should be sufficient, connect using 5A Fuse and 17AWG/1.00mm2 cable
Water Pump - Follow manufacturer guidance on fuse and cable size. This will vary between manufacturers and models. A small submersible pump typically requires a 5A fuse and 17AWG/1.00mm2 cable
Diesel Heater - Heaters are provided with a suitable cable and fuse. If you need to extend the cable, the voltage drop can cause faults during start-up due to the high current draw. Consult the manufacturer's instructions if modifying the wiring harness. For help choosing a heater read the following article.