Installing a LiFePO4 Battery and Renogy DCDC Charger: Peugeot Expert Camper Conversion
- Aug 10
- 7 min read
Updated: 6 days ago
Welcome to the 11th instalment of our camper conversion series! In this post, we'll be installing a 12v electrical system in our 2020 Peugeot Expert. You'll find a step-by-step guide along with helpful tips and tricks for your own project.
Item List:
Eco-Worthy 280Ah LiFePO4 Lithium Battery: Link
Renogy 50a DCDC Charger: Link
Wire: 6awg/12awg/22awg
Isolator: Link
Fuse Block: Link
Midi Strip Fuse Holder: Link
Heat Shrink Wraps: Link
Basic Layout:
We begin at the starter battery, connecting the positive cable to the positive terminal. Then there's a fuse placed as close as possible to the battery.
We'll be using 6-gauge wire and 60-amp fuses, as the total cable length will be under 6 metres.
Next, the cable is routed through the cabin and into the back of the van. From there, it connects to an isolator switch, which allows you to disconnect the system when it’s not in use, allowing you to isolate the electrical system for safety or maintenance.
The cable then runs into the 50-amp Renogy DC-DC charger. This is needed if you’re using a LiPo4 battery, as it prevents the battery from drawing too much power, which could damage your alternator. It also helps to prolong the lifespan of your leisure battery and ensures it charges fully.
After the charger, a fuse is installed next to its positive output. It’s important to place a fuse after each major component. From there, the cable connects to the positive terminal of the leisure battery. It then enters another fuse before it joins the main fuse board.
From the fuse board, the system distributes power to various appliances such as the fridge, plug sockets, and lights.
The negative output from the charger goes directly to the battery, which is then connected to the negative terminal on the fuse board. Finally, the negative terminal of the fuse board is connected to the ground point, completing the circuit. See installation order below.
Step One: Installing Components and Drilling Access Holes
I started by screwing in the isolator switch, DC-DC charger, and fuse block, along with their relevant fuses. I made sure to leave enough space so the wires could easily reach from one component to the next.
Once everything was installed, I moved on to drilling the holes so the cables could go to and from the leisure battery under the bed.
Step Two: Connecting the Positive Cables
I used the large cable cutter and wire crimper set to prepare the cables. Cutting the cables to length, placing shrink wrap over the end, then compressing the lugs. Finally, I used a lighter to shrink the wrap to cover the ends of the cables.
I connected everything except the DC-DC charger and leisure battery, as the negatives/ground points need to be done first so the charger can establish a stable zero ground reference point. (I'll cover that later on in the post.)
Tip: Having a selection of wire lugs from M4 to M10 will come in useful, as you'll have all options covered.
Step Three: Installing the Main Power Cable
We ran the positive line from the isolator switch along the back of the seats and under the step on the passenger side. From here, it went up to the glove box and passed through a rubber grommet into the engine bay.
Tip: It's important to set the isolator switch to off when you connect the power cable so the rest of the system remains uncharged.
We also taped the ignition sensor to the larger 6 AWG positive cable, as it will be following the same route to a fuse in the glove box. The ignition sensor is needed because the van is Euro 6 compliant and has a smart alternator that varies the voltage—we'll go into more detail later on.
Running the cable under the passenger step can be done by removing the trim, but that requires unscrewing the seatbelt, which I didn't want to mess with. I removed a small piece of plastic so I could pull the wire under the step. Then I used a second cable, which I pulled through from the other side with a coat hanger, to pull the main one towards the glove box after taping them together.
From the other side of the step, the power cable can pass up through the glove box and out through a grommet into the engine bay.
This is where the power cable and ignition sensor part ways, with the ignition sensor ending in a fuse in the glovebox.
The trim around the glovebox can be pulled away easily. Then there are 5 screws and one bolt to remove to gain access to the rubber grommet. The grommet can be pushed out from the front cab towards the engine.
Then the cable can be pulled through from the engine bay and cut to the appropriate length. I installed a fuse onto the plastic cover over the fuse box in the engine bay. Then I cut and connected a shorter cable from the fuse to the battery.
The van came with a quick-release connector on the positive terminal of the starter battery. This made connecting the power cable a little more difficult. We drilled a hole at the back of the positive quick release connector so we could attach the cable while still leaving enough room for the connector to sit all the way down on the terminal.
Once everything was connected, I installed the 60 amp fuse, covered the cables with conduit, and secured everything in place with cable ties.
Tip: It's much easier to push a cable through the conduit rather than trying to squeeze it over once it's already been installed.
Step Three: Installing the Ignition Sensor
The ignition sensor is needed if you have a smart alternator so that the DC-DC charger knows when the engine is on.
I used a voltmeter to test the fuses in the fuse board in the glove box.
I set the voltmeter to the 20v setting and placed the black probe on the metal of the van and the red probe on the pins on the fuse. Then, I used a piggyback adapter to connect the ignition sensor to a fuse that only receives power when the engine is on.
With the sensor cable in place, I reinstalled the trim and used some conduit to protect the thinner wire in the places with sharp edges.
Step Four: Installing the Ground and Finishing the Positive Cables
I cut away some of the carpet on the wall of the van next to the fuse block and used a wire brush to expose the raw metal.
Then I connected the negative from the DC-DC charger to the leisure battery. Then the negative from the leisure battery to the negative on the fuse block. And finally, the negative from the fuse block to the ground point. Then it was safe to connect the positive power cables from the DC-DC charger to the leisure battery and fuse board.
Why I wired my DC-DC charger in this exact order:
Zero Ground Reference: I connected the negatives and ground first to establish a stable reference point for the DC-DC charger.
Isolator Switch Protection: Keeping the main isolator switch turned off blocked the battery's charge and kept the wires completely dead and safe to handle while routing.
Insulated Wooden Setup: Because my battery bay is completely surrounded by wood, saving the positive connections for last was the easiest way to finish the circuit. With no risk of short-circuit due to a metal tool touching the metal wall of the van.
Step Five: Start-Up Checks and DC-DC Charger Set-Up
It was at this point we could turn the isolator switch to the 'on' position and start up the system for the first time. After a few seconds, the lights on the Renogy charger should turn on.
The next step is setting the battery type using a button on the bottom left of the charger, just below the ignition sensor input. Blue is for lithium. The LED above the battery status indicator should turn yellow once it recognises that the levels are correct. A red LED above the alternator symbol shows when the charger is drawing power.
At this point, you can connect the Bluetooth adapter so you can see the battery's charging status on your phone.
Step Six: Connecting Appliances
Now that we had confirmed the system was working, the last task was hardwiring the fridge and plug socket to the fuse block.
I cut the plug off and split the positive and negative cables. The process was similar to preparing the 6 AWG cables, just using smaller cutters, crimpers, and connectors.
How to find the positive cable if it's not identifiable by colour
If both of the wires are black and you need to find the positive, the easiest way is to look at their shape; the positive is normally round, while the negative will have flat edges that can be felt in your hand.
If this isn't an option, you can cut the plug and test the wires with a voltmeter set to the continuity setting. Place a probe from a voltmeter on the end of the plug, then the other to each of the cables. The one that beeps is the positive.
Tip: If both of the cables are exactly the same, you should mark them before cutting them.
Once the connectors were installed, I passed the wires through the back of the bed and connected them to the fuse board. Before finally installing the appropriate-sized fuse for the appliance.
The Alpicool fridge came with a 15 amp fuse in its plug, so I matched it on the fuse board.
But you need to calculate the correct fuse size; you can divide the device's wattage by the system voltage to find the base current, then multiply by 1.25 V for a standard 25% safety margin.
Start to Finish Walkthrough:
What's Next?
The next step in the conversion will be building the cabinets and sink. Sign up to get notified when we post our next update, or alternatively subscribe to my YouTube channel.
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