Everything here
- What state of charge means on a home battery
What the percentage on a home battery or power station measures, how it relates to empty and full, and why it's a gauge rather than a ruler.
- How a battery works out its percentage
How a battery's electronics estimate its charge level from voltage and current, and why each method has weak spots.
- What a backup reserve setting does
How a backup reserve setting holds back part of a home battery's charge for outages, and what that leaves for everyday use.
- Reading the battery app screens
What charge, discharge and standby labels usually mean in a home battery app, and which makers' pages say so.
- Turning a percentage into hours of backup
A step-by-step way to estimate hours of backup from usable capacity and load, and why a battery's percentage needs care.
- Why the percentage jumps or drifts
Why a battery's percentage can fall fast, stall near full, or jump after a rest, based on makers' and reference pages.