Mains Battery Charger for a Campervan: What to Buy and How to Wire It
A mains battery charger (sometimes called a shore power charger or converter) lets you charge your campervan's leisure battery from the 230V hook-up supply at a campsite or from a domestic socket. Here is what to buy and how to install it.
Types of campervan mains charger
Standalone battery charger: Plugs into 230V mains, outputs DC to the leisure battery. Simple and effective. Best for builds where the mains connection is solely for battery charging.
Inverter-charger (combined unit): A single unit that both converts battery power to 230V (inverter) and charges the battery from 230V when hook-up is connected (charger). Examples: Victron MultiPlus, Victron Phoenix Inverter with separate charger, Mastervolt. Best for builds that need both an inverter and a charger — saves space and cost vs separate units.
For most van builds, a standalone smart charger plus a separate inverter is perfectly adequate.
Charger sizing
The charger output current determines how fast it charges the battery:
| Charger output | Charge time (100Ah LiFePO4, from 20%) | Notes |
|---|---|---|
| 10A | ~8 hours | Too slow for campsite stays |
| 20A | ~4 hours | Suitable for overnight charging |
| 30A | ~3 hours | Good all-round choice |
| 40A | ~2 hours | Fast for large banks (200Ah+) |
| 60A | ~1.5 hours | Inverter-charger territory |
For most van builds with 100–200Ah batteries, a 20–30A charger is adequate.
Must-have features
LiFePO4 profile: If you have LiFePO4 batteries, the charger must have a dedicated LiFePO4 charging profile (14.4V absorption, low float). Many chargers sold for "all battery types" only support lead-acid profiles. Check the specification explicitly.
Temperature compensation: Adjusts charge voltage based on battery temperature. Useful for AGM, less critical for LiFePO4.
Bluetooth / app control: Victron Blue Smart chargers offer full monitoring via the Victron Connect app — useful for checking charge status remotely.
Input voltage range: Ensure the charger operates on 230V (UK standard). Most modern chargers are universal 100–240V.
Recommended chargers
Victron Blue Smart IP67 12/25: 25A output, IP67 waterproof, LiFePO4 and AGM profiles, Bluetooth. Works on 12V and 24V with different models. ~£130–160. The most popular choice in UK van builds.
Victron Blue Smart IP22 12/30: 30A, 3-output (can charge multiple batteries simultaneously). ~£120.
CTEK MXS 25: 25A, well-regarded quality, supports LiFePO4. ~£150.
Renogy 40A DC Home Battery Charger: 40A, good value, LiFePO4 profile. ~£90.
Wiring a standalone charger
The charger needs:
- 230V input: Plug or hardwired connection from your hook-up inlet
- DC output: Positive and negative cables to the leisure battery
230V side:
- If the charger has a standard 3-pin plug: plug into a 230V socket connected to your hook-up inlet
- If hardwired: connect to the hook-up consumer unit or a dedicated circuit breaker after the RCD
DC side:
- Run positive cable from charger output positive to the leisure battery positive (or main bus bar)
- Run negative cable from charger output negative to the leisure battery negative
- Fuse the positive cable close to the battery — inline blade fuse or ANL fuse, rated slightly above the charger's output current (a 30A charger uses a 40A fuse)
Cable size for DC output:
- 20A charger: 4mm² cable
- 30A charger: 6mm² cable
- 40A charger: 10mm² cable
Integration with a hook-up inlet
Your van needs a 230V inlet socket (blue CEE 17 "caravan connector" or domestic-style inlet) to accept a hook-up lead. This inlet connects to:
- A 30mA RCD (for safety — protects all 230V circuits from earth faults)
- An MCB (miniature circuit breaker) for each circuit, including the charger circuit
The mains charger's 230V input connects downstream of the RCD and MCB. This means it is automatically protected without needing the charger to have its own circuit protection.
FAQ
Can I leave a mains charger connected indefinitely?
Yes — quality smart chargers (Victron Blue Smart, CTEK) switch to a safe maintenance mode (low-voltage trickle) once the battery is full. They do not overcharge. For LiFePO4, the charger should reduce to 13.5V float or stop entirely once absorption is complete.
Do I need a charger if I have solar?
Solar handles day-to-day charging when there is sufficient sun. A mains charger supplements solar on dark days or at campsites. Many van lifers find solar-only adequate in summer but value a mains charger for autumn/winter or sustained overcast periods.
Can I use a car battery charger on a leisure battery?
A car charger designed for starter batteries uses different profiles (higher voltage, extended absorption, often equalization cycles). Do not use a standard car charger on a LiFePO4 battery. An AGM leisure battery can use an AGM-rated car charger, but a dedicated leisure/caravan charger is better.