I have been trying to coulomb count to identify how much charge is stored in a battery. They way I do this is as follows:
Every second, I measure how much current is fed to the battery.
Charge would be the integral of the current. In other words, If I found the area under a Current VS. time graph, I find the charge.
I am implementing this on Arduino. Since Arduinos are not easily capable of doing integration, I am finding the area by doing current*1 second for each value, so essentially I am adding all the current together since they are taken at 1 second intervals.
This gives me a capacity value in As.
There are Problems with this
I am somehow creating energy. For example for one cycle, It took 600 seconds to charge but it took 640 seconds to discharge, since the current is constant, that means the battery is somehow discharging more current than it was charged with!
When I charge at a higher current 800mA for example, I get much much smaller capacity ratings than If I charge with smaller current, 250mA. How on earth does this make sense?
当我在250毫安充电,值更接近the nominal value listed on the website (500mAh). When charging at 750mA, I get something along the lines of 380mAh.
For my case, these are the batteries I am using the following batteries :https://www.ampsplus.co.uk/ampsplus-14500-3-2v-500mah-battery-button