Sometimes you get higher capacity at higher discharge rate because the battery âdoesnât get discharged completelyâ. This is why energy is a much precise way to measure the real capacity because it can be translated directly into lumens/hours.
I concur energy is a more precise way of measuring absolute performance or delivered energy.
The area below the line curve is delivered energy, which is the integral of the voltage curve over the delivered capacity for the given voltage range and discharge rate. Or something like that, haven't touched formal maths for ages.
When the battery is discharged to 2.5V, the discharge capacity of large current may exceed that of small current. But there wonât be much difference.
Because of temperature induced chemistry reactions inside the cell. As a general rule heat improves the performance to some extent, chemistry dependent of course. While lots of modern cells do not show increased capacity at larger discharge ratios, increased heat reduction in internal resistance is common.
That was my thought as well. I have seen li-ions that were cold and run under a 3 amp discharge actual slightly increase in voltage as they were being discharged because the internal heat from being discharged warmed the cell which gives it the ability to provide more current. Since the discharge current is constant the cell doesnât have to work as hard warm so the voltage goes up slightly. A warm cell will give more capacity in a discharge test than a cold one in my experience.
No problem. It may just be the nature of this charger/analyzer (Lii-500). It consistently indicates lower capacity figures on all cells I test with it by about 5-6%.