Can individual cell voltage be measured?

[Aussie newbie]

I am currently running a 3 cell 1800 mAH pack. My charger (swallow advance) only tells me the overall pack voltage. Is there any way to measure each individual cell voltage? Perhaps using the balance tap on the battery? Any suggestions?

Thanks.

[Pinecone]

Yes, you can using the balance tap.

The wiring is:


- Cell 1 + - Cell 2 + - Cell 3 +

So from one end you have the negative to Cell 1, the next pin is the positive for Cell 1 and the negative for Cell 2. The next is the positive for Cell 2 and the nagative for Cell 3, and the last pin is the positive for Cell 3.

BE VERY CARFULL accessing the pins. You can easily short a cell and do damage to the pack.

[Aussie newbie]

Please forgive my ignorance Pinecone. I have very basic knowledge about electronics. Could you please give me step by step instructions on how to measure the cell voltage and what equipment I might need to do so.

Also for a pack to be in balance what should the differences in cell voltage be?

Many thanks.

[Pinecone]

If you aren't used to working around electrical stuff, I would say just get a balancer and let it do the work.

But to do it, you need a voltmeter, and some wire to use as pins to access the balance tap. You stick a pin into the end hole and the next hole and use the voltmeter to measure the voltage of the cell. BE VERY CAREFULL, if you touch the two pins together or touch both pins with the voltmeter lead you will short that cell and may do serious damage to the cell, including causing it to "vent with flames."

As for what voltage difference, the preferable is to be less than 0.03 volt difference cell to cell. Over 0.2 volts per cell and you have a problem.