how do i find a bad cell?
#1
how do i find a bad cell?
i think have a bad cell in one of my packs.fully discharged my millenium pro says that the pack has over 6 volts. and will only charge it for about 20 seconds. when i put my multi meter across each cell they all read the same. what gives? and how can i figure out wich one it is? (4cell nicad)
#2
Re: how do i find a bad cell?
The easy way is to put them in a turbomatcher .
There are a couple of other ways though. Often when a cell goes bad, it will get extremely hot while it charging or discharging, so keep an eye out for that. Assuming that doesn't work, a more tedius method is to disassemble the 4 cell pack in question. Take a 4 cell pack that works, remove one cell from the working 4 cell pack and replace it from one from the faulty pack, try cycling the pack, if it fails, there's your bad cell, if not, keep trying to you find it.
John
There are a couple of other ways though. Often when a cell goes bad, it will get extremely hot while it charging or discharging, so keep an eye out for that. Assuming that doesn't work, a more tedius method is to disassemble the 4 cell pack in question. Take a 4 cell pack that works, remove one cell from the working 4 cell pack and replace it from one from the faulty pack, try cycling the pack, if it fails, there's your bad cell, if not, keep trying to you find it.
John
Originally posted by sean
i think have a bad cell in one of my packs.fully discharged my millenium pro says that the pack has over 6 volts. and will only charge it for about 20 seconds. when i put my multi meter across each cell they all read the same. what gives? and how can i figure out wich one it is? (4cell nicad)
i think have a bad cell in one of my packs.fully discharged my millenium pro says that the pack has over 6 volts. and will only charge it for about 20 seconds. when i put my multi meter across each cell they all read the same. what gives? and how can i figure out wich one it is? (4cell nicad)
#3
Re: how do i find a bad cell?
Originally posted by sean
i think have a bad cell in one of my packs.fully discharged my millenium pro says that the pack has over 6 volts. and will only charge it for about 20 seconds. when i put my multi meter across each cell they all read the same. what gives? and how can i figure out wich one it is? (4cell nicad)
i think have a bad cell in one of my packs.fully discharged my millenium pro says that the pack has over 6 volts. and will only charge it for about 20 seconds. when i put my multi meter across each cell they all read the same. what gives? and how can i figure out wich one it is? (4cell nicad)
coop
#4
Tech Addict
More help I hope
The best way is to put the pack in a tray then read the voltage of each cell. A bad one will be 0 volts or really low. Most will be in the 1.2 range.
Some signs:
Heat shrink or label blurred,
Heat shrink or label coming off cell
leakage at the + end will look like acid on one cell
Charge the pack as much as you can. put on a load like bulbs or a discharger or a tray. Read the voltage of each individual cell as it is discharging. I f you have a bad one it will be obvious.
David Root
Or you could send the pack with the motors
Some signs:
Heat shrink or label blurred,
Heat shrink or label coming off cell
leakage at the + end will look like acid on one cell
Charge the pack as much as you can. put on a load like bulbs or a discharger or a tray. Read the voltage of each individual cell as it is discharging. I f you have a bad one it will be obvious.
David Root
Or you could send the pack with the motors
#6
It gets hotter than the other cells while charging, easiest test.
#7
Re: how do i find a bad cell?
Originally posted by sean
i think have a bad cell in one of my packs.fully discharged my millenium pro says that the pack has over 6 volts. and will only charge it for about 20 seconds. when i put my multi meter across each cell they all read the same. what gives? and how can i figure out wich one it is? (4cell nicad)
i think have a bad cell in one of my packs.fully discharged my millenium pro says that the pack has over 6 volts. and will only charge it for about 20 seconds. when i put my multi meter across each cell they all read the same. what gives? and how can i figure out wich one it is? (4cell nicad)
With some of my older packs, I've experienced that if they have rested for several weeks (discharged), my Eagle CDC 6.0 try to charge. After a couple of minutes, the charger stops, with the error message: Batt. voltage too low (or something like that).
If I afterwards pot a few miliamps in the pack with a 7,2 volt power supply, the voltage raises and the CDC charges normally.
But if it's a bad cell, GCoopers methods is good.