Affect of temperature on voltage and current of battery

[EchoX]

If this is not in the right forum, I apologize. I was just thinking that this would fall under electrical engineering, which would be a technical question suitable for this forum, and since I know most of you are educated people, I need your input on this.

If the temperature of a battery increases, would the voltage drop? And if it decreased, would the voltage go up? And is the current directly proportionate to the voltage, yieling the same results? Or do I have all of this info backwards? I read this here but I also found a contradiction here (scroll down to temperature).

[EchoX]

Also, how much resistance is needed to measure the current of an Energizer e2 battery (1.5v). It does not list the mAH on the battery or the website.

[hitech]

Since the production of current in a battery is the result of a chemical reaction, and chemical reactions generally happen "faster" at higher tempratures, it makes sense that you get "more" out of a battery at higher tempratures. However, I'm NO expert.

[athomas]

The operation of a battery increases at a higher temperature. This means it can deliver more of its current capability in less time. However, at a higher rate of discharge, the heat produced combined with the higher starting temperature can have a detrimental effect on the longterm lifespan of the cells.

A fairly heavy rheostat and a current meter would be what you need to measure the current output from a battery. Start with the rheostat set at a high value and gradually turn down the resistance while reading the current and voltage output. Write down your values. You will get an idea of how the battery is reacting under load. Be sure you record the time at each setting to help determine the total mA hours of current delivered.

[the electrician]

http://data.energizer.com/[/URL]

this will have the capacity of all the energizer brand batteries.

heat causes higher resistance. electricity does not like heat. the internal resistance of the battery will go up if a battery gets warm or hot. this means less maximum current draw will be possible. this is why batteries say right on them "do not use when battery is hot"

at the same time too cold and the battery does not have the ability to produce as much current due to the slowed chemical reaction. they all have a recommended operating temp range.

~E~

[undrdg]

this can be the cause of fSDO on most markers at low temp.

[athomas]

What the electrician said is absolutely true.

To expand, the chemical action of the battery increases at higher temp. The internal resistance also increases. At some point, the amount of heat causes the resistance to increase at a greater rate than the increase in chemical action. So, the result is less output past a certain temp. As the temp goes down, the chemical action decreases but so does the internal resistance. At some low temp, the chemical action will be reduced such that even with the lower resistance, the overall output will decrease.

The result is that the battery has a useable range of temp. This is usually stated on the case for the battery inquestion.

[Cristobal]

I'm no expert, but I imagine that most paintguns would have a DC voltage regulator between the battery and the control logic, with the output set below the expected minimum battery voltage.

Since the regulator *should* be designed to be stable despite temperature variation, the supply to the board should be unaffected by temperature-induced battery variation... unless the output voltage or current from the battery drop below the level needed to operate the marker.

[athomas]

It's not the control logic that causes problems due to current draw. Its the higher power solenoids and such that drag down the voltage due to high load demands. These may be ran through a regulator or maybe fed directly to the device and switched by a silicon device.