Inverter Sizing
The inverter converts DC battery power to AC for your appliances. Size it for the right reason: not your total wattage, but your peak simultaneous load plus the surge that motors draw at startup.
Motor surge is the trap
A water pump rated 550 W can draw two to three times that for a fraction of a second at startup. If the inverter cannot deliver that surge, it trips. VoltForge flags motor loads and adds headroom so the inverter you choose actually starts the things you plug in.
Standby tare eats your battery
An inverter consumes power even when nothing is running — its standby or tare load, running 24/7. On a small system this can be a meaningful fraction of your battery. The calculator includes tare in the energy budget so your autonomy estimate is honest.
Common questions
Pure sine or modified sine?
Pure sine is safer for motors, electronics and anything with a power supply. Modified sine is cheaper but can damage or misbehave with some loads.
How much surge headroom do I need?
Depends on the loads — motors need the most. The calculator applies per-load surge factors; always confirm against the specific inverter's surge rating.