[Help] My battery is always at 100%

[John Colvin]

(08-27-2015 01:23 PM)Tugdual Wrote:  If I'm not mistaken, only the current is changing during a charging phase while a (constant) voltage source is applied. Thing is that the Prime seems to detect only voltage, which by definition reaches a pick during recharge. An alternative would be to programatically disconnect the voltage source and measure battery voltage to give an indication of charge, not the sure the hardware permits that.

Lithium ion batteries don't show any significant change in voltage until they are almost discharged and then the voltage drops off fairly rapidly. A Coulomb counter would be a better circuit for a more accurate battery fuel gauge. It measures the charge going into or out of the battery instead of the battery voltage and gives a more accurate measure of battery charge with finer granularity.