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battery pack question

roughshawd

Jul 13, 2020
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What are the chances that every cell in a battery pack would fail all at once, and that all of them would not take a charge?
 

kellys_eye

Jun 25, 2010
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Slim.

It only takes ONE to fail to have charging issues but that also depends on the chemistry and the way the cells are connected (series/parallel or a combo).
 

Arouse1973

Adam
Dec 18, 2013
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How long has it been since it was last recharged? What load is the battery pack supplying?
Thanks
Adam
 

Externet

Aug 24, 2009
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If the battery pack has a charge controller circuit inside; it may be preventing from charging by either a failure, smoke missing; corrosion, a broken battery connection, a weaker than limit-discharged cell.
Measure each, inspect and come back.
 

roughshawd

Jul 13, 2020
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It all looks good inside. There is a bit of moisture stain on the insulating paper top and bottom, there are 15 1.2v 1300mah cells in series.
I put a pair of the cells in my ever ready ni-cad charger, but that amperage is not proper and it started to overheat, so I pulled them out.
I don't know why the wall wart isn't doing its job. The 'charge' led doesn't light. maybe overnight?
 

Externet

Aug 24, 2009
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Each cell must be voltage probed and its ends sanded to ensure contact. Any open cell or contact will prevent the pack to recharge. A heating what? charger or cell? can mean shorted cells. What is the 'wall wart' measured output voltage ?
 

kellys_eye

Jun 25, 2010
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NiCads huh? Notorious for failure - at least one will be dud.

As above, measure each cell individually and discard any that don't read at least 0.5V. There are some suppliers who offer replacement cells - and others that will offer a complete battery - but NiCads are 'old hat' and have, for the most part, been replaced by lithiums. I've converted a 24V NiCad 1/2" impact driver to work from a 20V lithium pack using a simple battery pack converter (a plastic device that fits into the OEM device and has a socket to take a different battery). Not as powerful as it could be but it does work and I have the right charger for the lithiums.

Check out the cell replacement costs before going further. You'll soon see what I mean.

Did you put them in the charger in the correct orientation?
 

roughshawd

Jul 13, 2020
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The pic is the sub-C that are in the pack. They are Ni-Cd Liang Ye SC1300mah 1.2v. I took a 15 pack from a different device but the same configuration, that didn't charge. I tried it in my current but it didn't work either, so I have chopped the packs up into sets of 2. I am charging them in an eveready multiple charger, it charges D, C, AA, AAA and 9v Ni-Cd. the Ni-Cd battery was made to outlast the nimh competition... I need to know whats wrong.. and why my Ni-Cd charger is heating up with 1.2v sub-c 1300mah bats.
 

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kellys_eye

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NiCads suffer from crystal dendrite growth which 'shorts out' the internal chemistry and both reduces the cell capacity to hold a charge and increase the current that flows through it when trying to charge it.

If your charger is smart enough it will limit the current but even if it limits it to its maximum capacity (whatever the manufacturer of the charger says it can do) it can still mean your charger dissipating more heat than you're used to 'feeling' under normal operation. Just because it's getting 'warm' doen't mean it's going to fail (but it might!).

If the NiCad 'discharged' voltage is under 1V I'd replace that cell for new. Certainly any that show '0V' (or thereabouts) shouldn't be reused. Purchasing enough replacement cells to rebuild a dodgy pack will likely cost more than a cheap new drill/battery setup.
 

roughshawd

Jul 13, 2020
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Thanks for bringing it all back to me. I really appreciate that. The original rechargeables we're designed to be integrated. The actual material wasn't ni-cad, but the raw natural ingredients were the ideal solution mathematically.
The ideal circuit failed horribly, so they (big money, no brainer) denied cap powered systems because of it. it set electronics back a hundred years. Some upstart built a super cap battery, and they bought it. The thing is that it takes more power to charge a super cap than it puts out. So... Micro miniturise the astrolabe and let's get going...( Ho Ho Ho ) Fat guy in a red suit carrying a big black bag full of stuff...!
 

roughshawd

Jul 13, 2020
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NiCads huh? Notorious for failure - at least one will be dud.
Back in the day,they always charged in stacks of multiple batteries, they always put a known bad one in as a "dud". I called that one my omega strain! Of course my Andromeda strain was the power I drove the micro circuit with.
 

kellys_eye

Jun 25, 2010
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they always put a known bad one in as a "dud".
No they didn't. One battery will inevitably fail before the rest - the odds on them all failing at the same time are incredibly remote and when ONE fails it causes the remaining cells to be placed under stress and liable to more failures ad infinitum.
 

roughshawd

Jul 13, 2020
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Thats why I hooked it up backwards!!! (didn't mean too.)
OK = POLR (my friend answers in the crowd).... "unless its ground" I waited a second and quietly said...
POLR only there is no bridge. They all claimed there was a such thing as POLAR... and I said "tap it and see if it is source or not". They said "..its only a source if it has polarity" I felt kind of left out but I decided it's only electricity if it has frequency. (thats how many times it goes back and forth from source to ground ain't it?)
 

davenn

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Sep 5, 2009
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and with that, we will close this thread
too many weird things
 
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