abating effect of battery

why at the end of battery period.it giving 1 volt instead of it actually 1.5 volt.why the internal resistance increasing and voltage decreasing at end time of battery.thank you in advance

Hello.

I have noticed that batteries start giving less and less voltage as they  deplete. I have a 9V battery, but it has been used for long periods of time to power my LED lamps. I notice that it's only giving off 3V when I suddenly realized that my 6V capacitors wouldn't blow up despited being connected to a 9V Battery.

A disposable alkaline battery uses a chemical reaction to produce electricity. The chemicals get used up which causes the internal resistance to rise. Then there is a voltage divider with the load resistance.

After one year I replace the 9V battery in my smoke detector. The battery voltage measures about 8V or more without a load but drops very low with a load caused by the voltage divider action. 

On 2/8/2014 at 12:48 AM, audioguru said:

battery uses a chemical reaction to produce electricity. The chemicals get used up which causes the internal resistance to rise.

Be especially careful when handling these types of batteries. Since they contain a large amount of chemicals, I advise you to familiarize yourself with the safety data sheets in order to follow the safety rules when working with them. In general, if you work with any chemicals, remember to use Material Safety Data Sheets to avoid putting your health at risk.