Why van owners switch to lithium
For a campervan or motorhome the leisure battery is the difference between one quiet night off-grid and several. Lithium pulls ahead on every measure that matters in a van.
- Twice the usable energy. Lead gives about half its rated capacity before you should recharge; lithium gives 80 to 90 percent. A 100Ah LiFePO4 does the work of roughly a 200Ah lead bank.
- Payload back. Lithium is about 70 percent lighter for the same usable energy, which matters when a van is close to its weight limit.
- Charges while you drive. With the right charger lithium takes a high current from the alternator, so an hour on the road can refill most of the bank.
- Fits where lead will not. Compact lithium packs slide under a seat or into a locker, and being sealed they can mount on their side.
The charging system is what really changes
This is the part most people miss. In a modern van you cannot just drop a lithium battery onto the old wiring.
- You need a DC-DC (B2B) charger from the alternator. A simple split-charge relay connects the leisure battery straight to the alternator. Lithium will then draw very high current and can overheat the alternator, and many smart or Euro 6 alternators drop their voltage too low to charge lithium at all. A DC-DC charger solves both: it limits current and forces a proper lithium profile.
- Set your solar controller to lithium. An MPPT controller must use the lithium profile, about 14.4V for a 12V pack, with float off. Lead-acid float settings hold lithium at the wrong voltage. See solar setup.
- Reset the mains hook-up charger too. Your shore or hook-up charger needs a lithium or AGM-style profile, not a flooded or desulfation mode.
Cold weather, monitoring and safety
Three more things finish the job.
- Winter use. LiFePO4 must not be charged below 0C. If you ski or travel in winter, choose a self-heating pack or fit a heater pad; discharging in the cold to run the heater is fine.
- Fit a shunt monitor. Lithium holds a flat voltage, so you cannot judge charge from voltage alone. A shunt-based monitor shows true state of charge.
- Re-fuse and do not mix. Check cable and fuse ratings for the higher currents, and never parallel lithium with an old lead leisure battery.
How many amp-hours does a campervan need?
Add up what you run on a typical day: a compressor fridge is the big one (often 300 to 600 Wh per day), then lights, water pump, phone and laptop charging, a diesel heater fan, maybe a small inverter. The finder tool turns that into a pack size, or start from your current battery.
| Van use | Lead-acid now | Lithium replacement |
|---|---|---|
| Weekender, lights and fridge | 1 x 100 to 110Ah | 1 x 50 to 100Ah LiFePO4 |
| Full-time, fridge plus inverter | 2 x 110Ah | 100 to 200Ah LiFePO4 |
| Big rig, induction or aircon | 3 to 4 x 110Ah | 200 to 300Ah LiFePO4 |
See the lithium battery that replaces your leisure battery
Enter your current leisure battery by amp-hours, group size, or brand and model, and get the lithium match plus the weight you save.
Size my lithium batteryCampervan lithium FAQs
Do I need a DC-DC or B2B charger for a campervan?
In almost all cases yes. A DC-DC (battery-to-battery) charger protects the alternator from the high current lithium draws and applies the correct lithium charge profile. It is also the only reliable way to charge from a modern smart or Euro 6 alternator, which lowers its voltage too far for lithium otherwise.
Will my existing split-charge relay still work with lithium?
Not safely. A voltage-sensitive relay connects the leisure battery straight to the alternator, so lithium can draw enough current to overheat the alternator, and a smart alternator may not raise the voltage enough to charge at all. Replace the relay with a DC-DC charger.
Can I use a lithium leisure battery in winter?
You can discharge LiFePO4 in the cold, but you must not charge it below 0C without protection. For winter vans choose a self-heating pack, or add a heater pad, and make sure your solar and DC-DC chargers respect the low-temperature cutoff.
How many amp-hours of lithium do I need in a van?
Most weekend vans are happy with 50 to 100Ah of lithium; full-timers with a compressor fridge and an inverter usually want 100 to 200Ah; large rigs with high loads go to 200 to 300Ah. Because lithium gives nearly double the usable energy, you can often fit half the lead amp-hours.