# Battery

Discussion in 'Homework Help' started by gicode0823, Apr 2, 2012.

1. ### gicode0823 Thread Starter Member

Feb 8, 2012
31
0
If AA battery is connected to small resistor, 0.5 ohm, for about 2 minutes and disconnect the resistor to measure the voltage across the battery,will the voltage across the battery recover right after disconnecting from the resistor?

I'm trying to measure the open-circuit voltage, which is the voltage across the battery, but seems like I'm getting different value depends on how long I wait from the disconnection.

Is there better way to find the open-circuit voltage?

Sorry if this doesn't make much sense... Kind of hard to explain...

well any helps will be appreciated

2. ### MrChips Moderator

Oct 2, 2009
12,636
3,455
If you wish to measure the voltage across the battery, just connect the voltmeter to the battery.

Why do you need to connect 0.5-ohm resistor across the battery?
3A is a lot to ask from an AA battery.

3. ### nsaspook AAC Fanatic!

Aug 27, 2009
3,016
2,375
Most batteries can be modeled using a two well model. You have an available charge well and a bound charge well. How long you have to wait until the voltage depends on the load and the chemistry of the cell. For a Zinc-Carbon AA cell the time should be short (10 to 30 min) to recover full cell voltage but the time to recover some lost capacity in mAh will be longer.

http://doc.utwente.nl/64866/1/battery-model.pdf