I am doing a simple experiment to analyse the discharge characteristics of a Lithium Ion battery to see how long it takes to discharge.
I have a 12V 4000mAh battery. Once charged, using a voltmeter I find that it has about 12V across it. I then put it in a simple circuit with a 6 ohm resistor. I estimated that this is the resistance that would cause it to discharge in 2 hours. After 10 minutes the voltage has dropped to 5V. This seems wrong and I may be doing this incorrectly.
Can anyone suggest a better way to measure the discharge characteristics of this battery.