Power Station Sizing
List your devices, watts, and hours/day. We calculate the required capacity in Wh.
About
Daily Wh = Σ (device watts × hours/day). Required capacity adds a safety margin for inverter overhead, battery depth-of-discharge limits and capacity fade with age.
How it works
- List every device that will run on the unit during one day.
- Be honest about hours — including standby loads (router, TV in standby, modem).
- Apply at least 20% margin; 40% for cold weather or aging batteries.
Frequently asked questions
What size power station do I need to run my fridge?+
A typical full-size fridge draws 100–150 W average and uses ~1.5 kWh per day. A 1,500–2,000 Wh LFP unit will run it for ~24 hours. For multi-day backup, look at 3,000+ Wh units or expandable systems with solar input.
What's a realistic safety margin?+
20% covers inverter idle losses (10–30 W) and 80% DoD on LFP. Add another 10–20% if you're running motors (refrigerator, fan) since their startup spikes are not in the average wattage.
Does the unit's nameplate Wh match what I actually get?+
Roughly. AC inverter losses subtract 10–15%; DC outputs (12 V port, USB) lose only 5%. Cold weather can reduce usable capacity by 20% on LFP. Brand-new LFP unit at room temp on AC: expect 80–90% of nameplate.
Should I size for surge or continuous?+
Both. Capacity (Wh) = continuous load × hours. Inverter rating (W) = surge load × 1.5. They are independent specifications and a unit can fail either: too small Wh runs out of energy; too small W trips on motor startup.