Hi, Jan Stary wrote:
Perhaps this is intended; does it mean that once the battery gets to a capacity of 1Wh, then having it charged to 1Wh will be a "full" battery? Would it be better if apm -l said the battery is (14.75 / 48.84) full now?
Exctly that. At each cycle, every battery, but especially LiIon, loose a bit of its capacity. So at every cycle your 100% will be less real capacity. Suppose that everytime you use gas in your car's tank, some residue remains, filling it up. But when it is full it is full, so that's 100%, even if the total gallons are less. So your total mileage drops, but you still need to know when it is empty (= you need to seek a gas station). The difficult part is that you can't measure how full it is, the circuitry tries to estimate that, so the comparison is valid only to a certain extent. A Li-Ion battery never has to be totally depleted and shall not be overcharged, so this is somehow tricky.
If the drop is well estimated, everything is fine. The problem I discovered is that since your battery is made of many elements, if some ruin before others then the estimate is usually wrong, e.g. overestimated.
In any case all this data is in the battery controller. OpenBSD just reads those values, you are free to interpret them. A full cycle, up to when the computer goes to shut/down, helps to recalibrate, but doesn't make miracles and with modern batteries works not so well.
Riccardo
