Estimates & learning

Built from your sessions, not a spec sheet

The home screen's headline number — a typical time to your charge target — is assembled from your own recorded sessions. Charge levels are cut into bands, each band gets the rate your phone has actually shown there, and the estimate is those bands added up. Tap the number and the app shows the evidence: how many sessions it rests on and how many bands they cover.

It says when it doesn't know

An estimate needs enough observed history before it means anything. Until your sessions cover at least 60% of the bands in the span being estimated, ChargeLog doesn't print a number — it says it is still filling in. The same rule guards the drain side: projecting whether the battery lasts until tonight requires real drain observations across enough of the hours in between, and below that threshold the app says "Learning your usage." A gap in the data is reported as a gap, not papered over.

Bands with no data inside an otherwise well-covered span are filled from their neighbours, and the app tells you so where it matters most: estimates lean optimistic near 100%, where the taper punishes assumptions.

Typical, or conservative

Estimates come in two styles: typical, straight from your history, or conservative, which adds 15% and says that it does. Pick whichever matches how much you like arriving early.

Health and cycles, with their sources attached

Deep stats can estimate battery health — capacity measured across substantial charges — and an approximate cycle count. Both depend on the cell's design capacity, and the app names where that number came from: reported by your device, or set by you. Phones often report it wrong, so if health reads above 100%, ChargeLog says the design capacity is probably wrong rather than congratulating you on a growing battery. Until enough qualifying charges exist, health reads "Still learning."