Energy calculator
Two practical tools: work out how long your battery lasts, or what you can safely plug into the campsite power hook-up.
How long will my battery last?
Enter your battery capacity (Ah) and the power of your device (W)
Usable energy
1080 Wh
You can use a device of 100W for
10 h 48 min
Calculation: 100 Ah × 12V × 90% ÷ 100W = 10 h 48 min
How does the calculation work?
Step 1 — Energy in Wh
Ah × volts = Wh (total energy in the battery)
e.g. 100Ah × 12V = 1200 Wh
Step 2 — Usable energy
Wh × efficiency (LiFePO4: 90%, AGM: 50%)
e.g. 1200 × 90% = 1080 Wh
Step 3 — Runtime
Usable Wh ÷ load in W = hours
e.g. 1080 Wh ÷ 100W = 10.8 hours
Campsite hook-up: what can I plug in?
Choose your hook-up (6A / 10A / 16A) and select your appliances
10A × 230V = 2300W — this is the maximum simultaneous load on this hook-up.
0% used
Select appliances above to calculate the load.
Tip: On arrival, always ask the campsite for the maximum current — it is sometimes on the power card, and sometimes not.
A smart plug (for example a Shelly Plug S) measures your real consumption in real time and warns you before you trip the fuse.
Do not forget to count the battery charger! As soon as you are plugged in, your house battery charges automatically via the charger (for example a Victron BlueSmart 12/20 ≈ 300W, 12/30 ≈ 480W). That load is always running in the background.
Victron users: set the AC input current limit in VictronConnect (for example 10A) — the MultiPlus then manages the balance between shore power and the battery charger automatically.
What do 6A / 10A / 16A mean on a campsite?
| Hook-up | Max. power | What will run? |
|---|---|---|
| 6 A | 1,380 W | Fridge, laptop, lighting, a small charger. No induction hob or kettle. |
| 10 A | 2,300 W | Fridge + laptop + TV + a small induction hob (low power). A typical EU campsite. |
| 16 A | 3,680 W | A full induction hob, air conditioning, a battery charger and a fridge at the same time. |
The figures are calculated at 230V single-phase (standard in Europe). Inrush currents of motors and compressors can briefly reach 2–3× the rated consumption.
Buying guides for power stations and solar panels are also on our sister site Zonneprep.nl.