Troubleshooting dead battery?

Jan 26, 2015
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#21
Before I start really disassembling the battery, this is what I found after tearing the first part of the shrinkwrap off. Are these the pins you are talking about (there's 11 of them) IMG_1644.jpg
 

wheeliepete

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#22
Are these the pins you are talking about (there's 11 of them)
Yes, that them, start one end, hopefully one wire is black, work along the pins, leaving neg. probe in the first pin, noting down the voltages. It should climb approx. 3v each time. Post your results.
 

Nealh

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Aug 7, 2014
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#23
10 pins will be v+ one for each cell and one end will be gnd/v-.
Probe the two end ones for polarity to see which one is v-.
Two ways of checking the 10 cells with probing accumaltive voltage reading or individual cell voltage reading.

For accumulative voltage reading stick Black probe in v- and just measure each of the other pins witht the Red probe.

For individual cell reading, Black probe /v- and Red probe in adjacent v+ for cell #1 reading.
For next cell #2 reading move both probes to the next adjacent cell (one at a time)until you have done this ten times, so Black probe always goes in to where the Red probe has just been.
 
Jan 26, 2015
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#24
Ok, here goes. Presumably some bad news. Measured between the first pin and successive:

1-

2. 4.10V
3. 4.58V
4. 5.26V
5. 9.36V
6. 13.47V
7. 17.57V
8. 21.7V
9. 25.8V
10. 29.9V
11. 33.5V

Looks like trouble on pins 3 and 4?
 

wheeliepete

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#25
Yes, you deff. have a couple of poorly(read dead) cells there, but now you know how it's done. Time gentleman please:(
 
Jan 26, 2015
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#26
Ok - so this is the end of the road for this experiment then? Battery goes to the dump?
 

vfr400

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Jun 12, 2011
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#27
You might get some life out of it if you charge the two low cells to around 4.1v the same as the others. Also, the last one needs charging. Use a 1S lipo charger. This one will do it, though a bit slow. If you pull the pins out of the connector, you can plug them straight in. You must put them in the right way round otherwise it will instantly blow.
https://www.ebay.co.uk/itm/1S-Lipo-...a70:m:mbLip25JQtup3sEzwKwA9jg&redirect=mobile
 
Jan 26, 2015
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#28
You might get some life out of it if you charge the two low cells to around 4.1v the same as the others. Also, the last one needs charging. Use a 1S lipo charger. This one will do it, though a bit slow. If you pull the pins out of the connector, you can plug them straight in. You must put them in the right way round otherwise it will instantly blow.
https://www.ebay.co.uk/itm/1S-Lipo-...a70:m:mbLip25JQtup3sEzwKwA9jg&redirect=mobile
Hey, thanks for this. I am just revisiting this thread.
Found this charger at home - would it work too?
IMG_2241.jpg
 

vfr400

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#29
Looks like it'll get the low cells up to 3.6v, which is a start, but you need to get the battery completely balanced before you can get any range out of it. Once you have the low cells at 3.6v, it will accept charging, but only until one of the high cells reaches 4.2V. After that, you have to drain the high ones down to match the low ones.
 
Jan 26, 2015
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#30
Ok, so I would connect the v+ on the charger to the pin with the low voltage and the v- on the charger to the v- pin on the end?
 
Jan 26, 2015
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#31
or no, to the adjacent cells I believe? in this case v- to pin 2 and v+ to pin 3
 

Nealh

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#32
or no, to the adjacent cells I believe? in this case v- to pin 2 and v+ to pin 3
Yes, that is correct.
The charger is for 3.6v if you, did it as in #30 then the charger would read too higher voltage and not do anything.
 
Jan 26, 2015
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#33
I just checked the voltage on the charger to make sure it was the right polarity. But it shows 6.3V! That can't be right? Or? SHouldn't it be showing 3.6V as indicated on the label? Or is charge voltage higher than the charge it can deliver?
 

Nealh

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#34
You can get a wrong voltage reading if the meter's battery is low or nearly had it.

If the charger voltage output is higher it doesn't matter as long as the charge rate is low, you just have to make sure the cell you charge doesn't over charge so check it with the meter every 10mins or so.

If I ever need to do any single cell charging I use a 5v cell phone charge and just carefully monitor the cell voltage.
 

vfr400

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#35
Some of these chargers pulse a higher voltage and switch off when they reach the designated voltage. The battery will dampen the pulses to an average, so it's not a problem, but you should monitor the charging to make sure it doesn’t go over, just in case.
 
Jan 26, 2015
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#36
Been trying the low cells now for a while, and nothing seems to be happening. Not sure if it's the charger, the connection or if they simply don't accept any charge at all. How long should it take to see any difference in voltage you think? Bear in mind the charger is 250mA according to the label.
 

vfr400

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#37
If they're anything other than 0V, they'll charge.. It takes 5 hours with a 2A charger, so it'll take 40 hours with your one, but it only goes half-way to 3.6V, so 20 hours.
 

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