On Tue, Apr 3, 2012 at 5:15 PM, Denis Heidtmann <[email protected]>wrote:
> I have a little routine which reports the value > in /sys/class/power_supply/BAT0/voltage_now. > > The battery for this netbook is listed as 10.8 V, 6 cell. Assuming Li PO4 > with a voltage of 3.6 V matches this (2 parallel; 3 series). > > The readings I get indicate just about 12 volts when fully charged. > Anybody have any idea what is going on? The readings indicate a > resolution of 2 mV. This implies a little more than 12 1/2 bits. Does > this seem reasonable? [This same routine on an ASUS eee pc 900 showed a > resolution of 9 mV.] > > My purpose is to understand the % charge remaining reported by the battery > monitor. > > Thanks, > > -Denis > I believe I was wrong about the Li Fe PO4, but correct about the 3.6V nominal per cell. But the maximum charge voltage is 4.2V, so seeing near 12V is not too far out of line. Now if I assume the lower limit on (safe) cell voltage is 3V, I can set my routine to read down to 9V and get meaningful data. -Denis _______________________________________________ PLUG mailing list [email protected] http://lists.pdxlinux.org/mailman/listinfo/plug
