how to test rechargable cells?
 

I have a nunchuk pack that will no longer take a charge.

I highyl doubt all 8 cells are capoot. But google is failing me on how I can properly check each one.

Taking them apart is easy. just need to know if I can meter them. or how to go about doing this?


Any help would be great!

Easy.

you can't change a single cell out of a pack.

All cells have to be the same age and use level.

Otherwise, the battery you have changed will be way better than the others and the old ones will crap-out one after the other.

Just get a new pack, it's dirt cheap.

There is a way to test a single cell... It is called a 3000$ charger.

For $100 I can save you $2990. :D

$9.99 multimeter with retractable hook clip probes and 2 pieces of thin metal to slide between batteries. make sure battery is not connected to anything.

(edit: or if you find it easy to take apart, take it apart and test with a multimeter)

you can get the voltage for each cell but is pointless as Kos-Mos has already mentioned.

alright than. Thats what i honestly thought.

Iw ould like to build my own batteries. Has anyone a good supplier for smaller batts in canada? and what brand is the best to go with?

I am trying to learn lipo's. may break into them next summer :)

Please dont lecture about safety. I am an avionics tech and spend a lot of time working with aircraft batteris. I jsut can't honestly say i've ever had a need to test a single cell rechargable.


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I was planning to remove a cell from the nunchuk anyway. to knock the voltage down a bit. so if it was ONE bad cell. I wouldn't be replacing. simply removing :) If the nunchuk won't take a charge how exactly do I check each batt for a voltage?

cheapbatterypacks.com is a good start. local hobby shops can be good too.

what is the current voltage on the entire pack?

once you break down the nun chuck battery, test each cell individually with a multimeter. they should all be similar in voltage. there will probably be one that is very low or dead. reassemble. charge (in a safe location in case it leaks). test. done

Well the voltage on the pack i THOUGHT was 9.6 but when i broke open the pack I decided to meter the whole pack first. and it was pulling 10.4 i think.

they were 1.3V a piece x 8 I removed one for now and knocked it back to 9.1

waiting to see how it works like that :)
I will meter the individual cells. they are all low as hell but if one is completely dead I will try replacing it and charging it again.

Voltage won't tell you squat. In order to properly test a battery you need a loadmeter, or some other way to test it under load.

You can get a complete built pack for about 30$

Each cell is 1.2v nominal. It means that if the pack is fully charger it will got higher, sometimes up to 1.5v each.

If your pack if very high voltage, it might mean that all the cells are dead. They will hold voltage but no capacity.

the cells work fine. i do not wish to buy packs i wish to build my own.

and these were fresh charged. gamed for a good 4 hours and than tested to be 1.3V

so i'm not sure at what point they run to 1.2 but I was running my gun on 8*1.3vdc when i meassured it...

ah yes, load tester/meter. how soon I forget. I guess it's been a while