Campervan electrical systems: lithium, solar, inverters, explained
What a real off-grid electrical system looks like in 2026, with the numbers from HubDub builds and a plain-English explanation of what each component does.
Co-founder of HubDub Campers. Writes most of what you read here. Spends the rest of his time in the Chertsey workshop.
More about HubDubModern lithium electrics are the single biggest reason a 2026 custom campervan is more useful than one from 2016. A well-specced electrical system turns a campervan from a vehicle that needs a campsite into a vehicle that can go almost anywhere. This piece explains what each component does, in plain English, with the numbers we use on real builds.
The four parts of a campervan electrical system
Every modern campervan electrical system has four parts: a battery bank that stores energy, sources that put energy into it, an inverter that turns the stored DC into household AC, and a control system that manages everything.
Battery bank
Lithium iron phosphate (LiFePO4) is the standard for serious campervans in 2026. It is heavier than lead-acid for a given footprint but far lighter for a given usable capacity, and it does not mind being part-charged. A 100Ah lithium gives roughly 95Ah of usable capacity. A 100Ah lead-acid gives around 50Ah.
HubDub default: six 100Ah Victron lithium batteries banked together, giving 600Ah of nominal capacity at 12V (roughly 7.2 kWh of usable energy). This is enough to run a fridge, lighting, water pump, kettle, induction hob, and a laptop for three to five days off-grid in shoulder season. In summer with solar, indefinitely.
Solar
Solar panels turn sunlight into DC power. The figure to track is peak watts (Wp), but the more useful number is realistic daily kWh in your average use season. In the UK, every 100Wp of roof solar typically delivers 0.25 to 0.4 kWh per day in summer and 0.05 to 0.1 kWh in winter.
HubDub default: 400Wp of monocrystalline panels in two pairs, with a single Victron MPPT controller. In summer this typically replenishes 1.0 to 1.6 kWh a day, which is more than a careful couple uses.
Charger and shore power
When parked at a campsite or driveway with mains, a charger turns 230V AC into 12V DC and tops up the battery bank. The charger size matters less than buyers expect. A 30A charger replenishes a 600Ah lithium bank from empty in roughly twenty hours. A 60A charger does it in ten. Most owners overnight, so 30A is fine.
HubDub default: Victron Multiplus 12/2000/80 combined inverter and charger.
Inverter
An inverter turns 12V DC stored in the battery bank into 230V AC suitable for household appliances. The size you need is the wattage of the largest appliance you intend to run on it.
- 1000W inverter: enough for a kettle, laptop chargers, hairdryer, lights.
- 2000W inverter: enough for an induction hob, kettle, microwave (small), laptop chargers, all at once.
- 3000W inverter: enough for a domestic-sized induction hob, oven (small), microwave, all at once.
HubDub default: 2000W. We rarely fit anything smaller, and we rarely fit anything larger.
Alternator charging
When the engine is running, an alternator charges the leisure batteries. On a modern Euro-6 base vehicle this needs a DC-to-DC charger to manage the voltage curve safely. We fit a Victron Orion 30A as standard, which puts roughly 350Wh into the bank for every hour of driving.
Putting it together
A standard HubDub off-grid electrical system is six 100Ah Victron lithium batteries, a Multiplus 12/2000/80, a 30A Orion DC-to-DC charger, 400Wp of roof solar feeding a Victron 100/30 MPPT, a Cerbo GX for monitoring, and a touchscreen GX display in the kitchen. Total component cost in 2026 is roughly £8,200. Total install cost including labour is roughly £14,200.
What you do not need
Three things buyers often spec and rarely use: a 5kW inverter (most appliances draw under 2kW); 800W of solar (anything above 400W rarely earns its weight on a UK roof); a generator (modern lithium plus solar makes it unnecessary in 95% of cases).
Common questions
For weekend use, 200Ah is enough. For week-long off-grid use in shoulder season, 400 to 600Ah. For full-time use or winter use, 600 to 800Ah.
If you ever park without shore power, yes. Even 200Wp is genuinely useful on a UK roof in summer. 400Wp is the HubDub default and a sensible upper limit.
1000W if your highest-draw appliance is a kettle. 2000W if you have an induction hob. 3000W only if you have multiple high-draw appliances and want to run them all at once.
Quality LiFePO4 batteries are rated at 3,000 to 5,000 cycles to 80% capacity. In typical campervan use that is roughly fifteen to twenty years.
Yes, with a 2000W inverter and a lithium bank of 200Ah or larger. Single-burner induction hobs are now standard on most HubDub builds.
