Question Why do rechargeable batteries lose charge when left unused ?


Jul 24, 2014
I have 2 pairs of AAA size rechargeable batteries. I use them to power my wireless headphone. Problem is suppose if I use the 1st pair and leave the 2nd pair after charging it loses chaarge all by itself.

Can someone tell me why this happens ?


All cells, whether rechargeable or not, have an internal leakage that will slowly discharge them whether or not they are in use. However, a week is far, far too short a period and indicates that those cells are in need of replacement.
Nov 24, 2019
All materials have some ability to conduct electrons. In the real world there is no such thing a infinite resistance to current flow or infinitely low pressure (voltage) to conduct electrons. Since nobody can measure anything close to infinity, a circuit exist inside a battery that creates tiny amounts of wasted energy as heat. Thus no battery can be stored for infinity. I agree with the other poster that 1 week is too short of a life of a battery. Yes the batteries can be defective and need to be replaced with better quality brands. But, a pattern of rapid discharge of batteries could be an indication that they are not being stored properly. The storage medium may be providing a path of current flow. At least they should not be stored randomly in a slightly conductive (metallic) container, an d don't toss then in a draw in a loose chaotic pattern touching the contacts together when closed. Years ago I got into the habit a placing all cells in a insulated container side by side with the poles facing in the same direction. Remember like charges repel, unlike charges attract including electrons in a battery. There are times I have used a rubber band to cover the terminals at the end of AA & AAA batteries. In the case of button cells I have used a piece of masking tape to accomplish this. Lastly make sure the charger is fully functional. If the headset is discharging the first set of batteries too soon and the headset is working normally, test the charger. Keep in mind that not all types of rechargeable batteries are equal. A fully charged NiCad should have a voltage of 1.25 volts. Nickel Metal Hygrades have higher voltages more closely resembling the old disposable carbon zinc batteries at 1.5 v. A cheapy voltmeter can help in figuring it out. Also batteries have differing current capacity that will effect how long they can last. Fortunately it's rare for batteries to have declining current capacity and not also show declining voltage readings. Best of Luck.