Battery

Thread Starter

gicode0823

Joined Feb 8, 2012
31
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
 

MrChips

Joined Oct 2, 2009
30,706
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.
 

nsaspook

Joined Aug 27, 2009
13,079
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.

KiBaM is a very intuitive battery model. In the model the battery charge is
distributed over two wells: the available-charge well and the bound-charge well
(cf. Figure 2). A fraction c of the total capacity is put in the available charge
well, and a fraction 1 − c in the bound charge well. The available charge well
supplies electrons directly to the load (i (t)), whereas the bound-charge well
supplies electrons only to the available-charge well. The rate at which charge
flows between the wells depends on the height difference between the two wells,
and on a parameter k. The heights of the two wells are given by: h1 = y1
c and
h2 = y2
1−c . The change of the charge in both wells is given by the following
system of differential equations:
http://doc.utwente.nl/64866/1/battery-model.pdf
 
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