The short answer. Size your van’s system by the amp-hours you use a day, not by a price. Find that number with the Battery bank size calculator. Small builds run one SmartSolar MPPT 100/20. Medium builds use the 100/30 that comes in the Van solar starter kit. Large builds add a bigger controller and DC-DC charging from the engine.
You’ll need
- Your list of what runs in the van, and for how long each day
- The Battery bank size calculator and the Solar array size calculator
- The Van solar starter kit: controller, monitor, main fuse holder, switch, busbars, fuse block, wire and terminals
- Your own battery, plus the battery maker’s charge voltages
- Your own solar panels
- For bigger builds, the Dual-battery DC-DC charging kit
- The Wire gauge calculator and Fuse size calculator, before you cut a single cable
“Budget” here means your power budget. That’s the amp-hours you use in a day, and it decides every part on this page. Get that number first.
You can do this. Here’s how.
What goes in a camper van electrical system?
Same parts in the same order, whatever the size of the van:
- Battery. Yours. Any 12V house battery, set up to its maker’s numbers.
- Main fuse. On the battery positive, as close as it fits.
- Switch. Turns the whole house side off.
- Shunt on the negative. The SmartShunt sits between the battery negative and everything else. It counts every amp in and out, so you read state of charge on your phone.
- Busbars. One for positives, one for negatives. Everything meets here.
- Charge sources. The solar controller first. Later, if you need it, a DC-DC charger from the engine.
- Fuse block. One blade fuse per circuit: lights, fan, pump, fridge.
- Loads.
The layout in detail: Busbars and fuse blocks: laying out a boat DC panel. Written for boats, same layout in a van.
How do I size my van’s electrical system?
Three steps.
- List your loads. Put every device into the Battery bank size calculator with its draw and hours per day. The calculator hands you daily amp-hours.
- Turn that into panel watts. Put the daily number into the Solar array size calculator along with your sun hours. You’ll get panel watts and the smallest controller that covers them.
- Pick your size below.
Here’s the calculator’s own example. Lights, a fan and a fridge come to 58 Ah a day. On 12V that’s 696 watt-hours. With 4 sun hours and panels making 75% of their label, you need about 237 W of panels. That’s a small build.
Small, medium or large: which parts?
Victron rates each controller for a set number of panel watts on a 12V battery. Those ratings set the break points. The amp-hour figures below are our math at 4 sun hours, 75% panel output and the controller’s 98% peak efficiency. Less sun means lower numbers, so always run the calculator with your own.
| Size | Daily use (4 sun hours) | Controller |
|---|---|---|
| Small | up to about 71 Ah | Victron SmartSolar MPPT 100/20 |
| Medium | about 71 to 108 Ah | Victron SmartSolar MPPT 100/30 (in the kit) |
| Large | over about 108 Ah | The kit’s 100/50 swap |
Panels: up to 290 W on the 100/20, 440 W on the 100/30 and 700 W on the 100/50, all at 12V. Every size still needs a monitor, fusing and a fuse block. Medium is everything in the Van solar starter kit. Large adds DC-DC charging from the engine.
Small. Lights, a fan, a water pump, phones. A short roof or a weekend van. The 100/20 handles 20 A of charge and up to 290 W of panels at 12V. You still want the monitor and the same fusing as a medium build.
Medium. Add a 12V fridge and you’re often here. This is what the Van solar starter kit is built for. The MPPT 100/30 charges at up to 30 A and takes up to 440 W of panels at 12V.
Large. Full-time living, a bigger fridge, an inverter, or a roof that can’t fit enough panels. Two things change:
- A bigger controller. The kit page lists the MPPT 100/50 as a swap. It charges at up to 50 A and takes up to 700 W at 12V.
- A second charge source. Use the engine. The Dual-battery DC-DC charging kit adds a Victron Orion-Tr Smart 12/12-30 isolated DC-DC, which gives the house battery up to 30 A whenever you drive.
Running anything off household outlets? Size the inverter with What size inverter for a boat, van or RV before you pick a size here. The inverter is usually the biggest load in the van.
Every controller on this list takes up to 100 V from the panels. Pick panels whose open-circuit voltage on the coldest day stays under that. Picking an MPPT: 100/20 to 150/60 in one table goes deeper.
What’s in the van solar starter kit?
It’s everything between your panels and your 12V loads, except the battery.
- Victron SmartSolar MPPT 100/30 controller
- Victron SmartShunt 500A monitor
- A class T main fuse holder, for 225 to 400 A class T fuses
- A sealed 500 A battery switch
- Two Victron Busbar 250A 4-point with cover
- An ANL fuse holder to feed the fuse block
- An Egis RT 12-position fuse block with ground, with a blown-fuse LED on each of its 12 circuits
- 100 ft of 14 AWG red and black duplex wire, and 100 heat-shrink ring terminals
Not in the box: the battery, the solar panels and their cables, battery cable and lugs for the main runs, a fuse holder for the controller’s battery cable, and the fuses themselves.
Bring your own battery. If your battery maker calls for a main fuse of 200 A or less, you need a smaller holder than the one in the kit. It only takes 225 to 400 A class T fuses.
When do I add DC-DC charging?
When the sun can’t keep up. That’s cloudy weeks, winter, a small roof, or a large daily number.
A DC-DC charger takes power from the van’s start battery while the engine runs. It charges the house battery on its own profile and limits the current. The Dual-battery DC-DC charging kit has the Orion-Tr, two fuse holders and a SmartShunt. Already have the shunt from the solar kit? Set that line to 0 before you add the kit to your cart. Victron gives a 60 A fuse for each 12V side of the 12/12-30.
Lots of newer vans have smart alternators, and that changes how the charger knows the engine is running. DC-DC charger for a camper van: smart alternators covers it van by van. For isolated vs non-isolated, see Orion-Tr isolated vs non-isolated. For DC-DC vs a combiner, see Charging lithium from a boat alternator: Orion-Tr vs Cyrix vs combiner.
Do I need a BatteryProtect in a van?
It helps on a medium or large build. A Victron Smart BatteryProtect 100A cuts the loads off before they run the battery too low. At default settings it disconnects at 10.5 V and reconnects at 12 V on a 12V system. It carries up to 100 A of continuous load.
Two rules from Victron’s manual:
- Current flows one way only, battery to load. Never put a charge source through it.
- Never put it on an inverter’s DC input. Use it to switch the inverter’s remote on/off instead.
How do I wire it? Step by step
- Isolate the battery first. Everything off, then disconnect the battery, negative first. Leave the panels covered or unplugged.
- Size the cable before the fuse. Run each length through the Wire gauge calculator, then pick the fuse for that cable with the Fuse size calculator. The cable sets the fuse, never the other way around.
- Main fuse at the battery positive. Then the switch, then the positive busbar.
- Battery negative to the shunt. Nothing else goes on that post. One cable from the shunt’s system side goes to the negative busbar.
- Controller to the busbars. Positive goes through its own fuse, 35 to 40 A for the 100/30. Its terminals take cable up to 16 mm² (6 AWG). Negative goes to the negative busbar, so the shunt counts the solar.
- Fuse block. Feed it through the ANL holder from the positive busbar. Run one circuit per blade fuse. Bring the small negatives to its ground bar, and run one cable from there to the negative busbar.
- Reconnect, positive first, negative last. Set the controller and the shunt to your battery maker’s numbers.
- Panels last. Uncover or plug in the panels only after the controller sees the battery.
That’s it. Let’s go.
Does this guide fit your van?
This applies if: – Your van’s house system runs on 12V. – You’re adding solar, a monitor and fusing around a house battery you already have or are buying elsewhere.
This doesn’t apply if: – Your house bank is 24V or 48V. The controllers on this page have 24V ratings, but the kit and the break points are worked out for 12V. – You’re adding shore power, a 120V inlet, or anything on the AC side. That needs a licensed electrician.
Your van, model by model
Each page covers one van’s alternator and factory wiring points, with the maker’s own numbers:
- Lithium house battery in a Ford Transit: charging
- Lithium house battery in a Mercedes Sprinter
- Lithium house battery in a Ram ProMaster
- Lithium house battery in a Chevy Express or Savana
Products in this guide
| Product | Why it’s here |
|---|---|
| Victron SmartSolar MPPT 100/20 | Small builds. 20 A, up to 290 W at 12V. |
| Victron SmartSolar MPPT 100/30 | Medium builds, and the controller in the kit. 30 A, up to 440 W at 12V. |
| Victron SmartShunt 500A | Reads state of charge on your phone. No screen to mount. |
| Victron Busbar 250A 4-point with cover | One for positives, one for negatives. |
| Egis RT 12-position fuse block with ground | 12 circuits with a ground bar and blown-fuse LEDs. |
| Victron Smart BatteryProtect 100A | Cuts the loads before the battery runs too low. |
| Victron Orion-Tr Smart 12/12-30 isolated DC-DC | Large builds. Charges the house battery while you drive. |
Prices show live from the store. Start from the Van solar starter kit, add the Dual-battery DC-DC charging kit for engine charging, or see every controller in Solar charge controllers.
Bundles for this job: Van solar starter kit, Dual-battery DC-DC charging kit
Quick answers
Does the van solar starter kit include a battery? No. It’s everything around the battery. Bring your own and set the controller and the shunt to its maker’s charge voltages.
Can I start small and grow later? Yes. Keep the layout and swap the controller up a size, or add DC-DC charging. The busbars, shunt, switch and fuse block stay put.
Do I need DC-DC charging if I have solar? Not always. If the calculator says your roof covers your day, solar alone can do it. If you drive a lot, live in the van full time, or park in shade, the engine is the easy second source.
Can I put the fridge on the BatteryProtect? Yes, that’s a common use for one. Loads go on its OUT side. Charge sources and the inverter’s DC input never do.
Sources
- Victron SmartSolar MPPT 75/10, 75/15, 100/15, 100/20-48V datasheet: https://www.victronenergy.com/upload/documents/Datasheet-SmartSolar-charge-controller-MPPT-75-10,-75-15,-100-15,-100-20_48V-EN.pdf
- Victron SmartSolar MPPT 100/30 & 100/50 datasheet: https://www.victronenergy.com/upload/documents/Datasheet-SmartSolar-charge-controller-MPPT-100-30-&-100-50-EN.pdf
- Victron SmartShunt datasheet: https://www.victronenergy.com/upload/documents/Datasheet-SmartShunt-EN.pdf
- Victron Busbar 250A with cover datasheet: https://www.victronenergy.com/upload/documents/Datasheet-Busbar-250-A-4P-and-6P-with-cover-EN.pdf
- Victron Smart BatteryProtect datasheet: https://www.victronenergy.com/upload/documents/Datasheet-Smart-Battery-Protect-65-A–100-A–220-A-EN.pdf
- Victron Smart BatteryProtect 12/24V manual, rev 05 (02/2025): https://www.victronenergy.com/upload/documents/Smart_BatteryProtect_12V_24V/114439-Smart_BatteryProtect-pdf-en.pdf
- Egis RT fuse block, 12 circuit with ground: https://www.egismobile.com/shop/8026b-rt-fuse-block-12-circuit-w-ground-bulk-4952
- Victron Orion-Tr Smart DC-DC Charger Isolated manual, Rev 14 (02/2026): https://www.victronenergy.com/upload/documents/Orion-Tr_Smart_DC-DC_Charger_-_Isolated/34439-Orion-Tr_Smart_DC-DC_Charger-pdf-en.pdf
