Portable Power Station Calculator: How long will the power station last when camping?
A 1,000 Wh power station sounds like a lot – but usually only 850 Wh is usable, and every watt-hour from the AC outlet costs 15% in conversion losses. This calculator shows how many days the station powers your devices, how long a single device runs on its own and how often you can charge your phone.
Result
The power station lasts for
1.1 days
with the devices entered per day
- Usable energy
- 850 Wh
- Daily consumption incl. losses
- 740 Wh
- Smartphone charges (phone only)
- 52
- at 15 Wh per battery
- Only “Compressor cooler 12 V” running
- 17 h 23 min
- The continuous rating of the AC output must be at least 65 W (largest appliance) – check the data sheet.
Show calculation
- 1Usable energy: 1,000 Wh × 85% = 850 Wh
- 2Compressor cooler 12 V: 45 W × 10 h ÷ 92% = 489 Wh (alone: 17.4 h)
- 3Charge smartphone: 10 W × 2 h ÷ 92% = 22 Wh (alone: 78.2 h)
- 4Laptop adapter 120 V: 65 W × 3 h ÷ 85% = 229 Wh (alone: 11.1 h)
- 5Daily consumption: 740 Wh → runtime 1.1 days
How it's calculated
usable energy [Wh] = capacity [Wh] × usable fraction
energy per device [Wh/day] = power [W] × usage [h] ÷ output efficiency
runtime [days] = usable energy ÷ sum of devicesSolo operation shows how long the station powers a single device: usable energy × efficiency ÷ power. The phone charges follow from the usable energy divided by the battery content (mAh × 3.7 V).
Worked example
A 1,024 Wh power station powers a compressor cooler (45 W, runs 40% of the time), two phone charges a day and two hours of laptop on the 120 V adapter in the evening over the weekend.
Inputs
- Power station capacity: 1,024 Wh
- 12 V/USB devices:
- Kompressor-Kühlbox 12 V: 45 W × 10 h/day
- Smartphone laden: 10 W × 3 h/day
- 120 V appliances:
- Laptop-Netzteil 230 V: 65 W × 2 h/day
- Usable fraction of capacity: 85 %
- Efficiency 120 V output: 85 %
- Efficiency 12 V/USB output: 92 %
- Smartphone battery (for the number of charges): 15 Wh
Result
1.3 days
The power station lasts for
- Usable energy
- 870 Wh
- Daily consumption incl. losses
- 675 Wh
- Smartphone charges (phone only)
- 53
- Only “Kompressor-Kühlbox 12 V” running
- 17 h 48 min
Calculation
- Usable energy: 1,024 Wh × 85% = 870 Wh
- Kompressor-Kühlbox 12 V: 45 W × 10 h ÷ 92% = 489 Wh (alone: 17.8 h)
- Smartphone laden: 10 W × 3 h ÷ 92% = 33 Wh (alone: 80.1 h)
- Laptop-Netzteil 230 V: 65 W × 2 h ÷ 85% = 153 Wh (alone: 11.4 h)
- Daily consumption: 675 Wh → runtime 1.3 days
The variables explained
- Capacity (Wh)
- Rated energy per the manufacturer. Ratings in Ah usually refer to 3.7 V cells (Ah × 3.7 = Wh).
- Usable fraction (%)
- The BMS shuts off before deep discharge; capacity also drops with age. 80–90% is realistic.
- Efficiency 120 V / 12 V (%)
- Losses of the inverter or the DC converters. Small loads on the AC output are particularly inefficient (idle consumption).
Common mistakes
- Calculating the cooler at rated power × 24 h – it cycles and only runs 30–50% of the time.
- Using the AC output for USB devices: charging directly via USB-C saves 10–20% in losses.
- Leaving the inverter on: some stations draw 10–20 W at AC idle – 100–200 Wh overnight.
- Confusing Wh and Ah: “100 Ah” of a power station at 3.7 V is only 370 Wh.
Assumptions and limits
- Constant efficiencies; idle consumption of the outputs is not included.
- No recharging during the period.