Revive Nicad Batteries

xoxoxoBruce · 03-22-2007, 10:13 PM

From Instructables, revive Nicad Batteries by Zapping with a Welder.

Quote:

Here's a method of bringing them back to life by zapping those shorted crystal dendrites away with too much current and/or voltage. We'll use a welder as a power source. You could also use a car battery, a DC powersupply, or almost anything with some voltage. Charged-up capacitors are popular for this because you can get a very fast pulse out of them and still limit the power. it's a lot safer that way.

SteveDallas · 03-22-2007, 10:20 PM

I wonder if it works for dilithium crystals.

xoxoxoBruce · 03-22-2007, 11:25 PM

What are they in, a dildo?

richlevy · 03-23-2007, 08:47 PM

Is that guy wearing a flak jacket? I hope so.

Dendrites? Weren't they the bad guys in Army of Darkness?

tw · 03-24-2007, 02:41 AM

Been doing this stuff for a long time. Won't go into details. However a precaution. Do not do that technique to lithium batteries. Unlike NiCds, Lithiums can explode harmfully.

Griff · 03-24-2007, 07:56 AM

Quote:

Originally Posted by tw

Been doing this stuff for a long time. Won't go into details. However a precaution. Do not do that technique to lithium batteries. Unlike NiCds, Lithiums can explode harmfully.

NiCds are cool though? This could have saved me some bucks...

xoxoxoBruce · 03-24-2007, 01:35 PM

Yeah, me too. If tw wasn't so busy playing to his lurkers, he could have been helpful.

tw · 03-26-2007, 01:42 AM

Trick to 'curing' NiCd typically was not performed as in that video. Most don't have a high current low voltage power source. We take a power supply and reverse apply voltage to an offending cell to accomplish same 'burnout'.

This problem is more often created by over discharging a series of batteries. Series as in four 1.5 volt batteries makes 6 volts. One weaker battery becomes so discharged that the other batteries actually reverse charge a weak cell. Then the weak cell shorts.

Solution was to drive a larger current in reverse across the battery to 'burn out the short'. Then charge each battery separately. Remember weak cells needs more energy. But if rechargeing then all in series, then a weak cell remains weaker. Batteries must be recharged seperately (or in parallel) so that the weak cell can accept more current - more energy.

The video did not show that concept and did not show why a weak cell would remain weak; to fail again.

03-22-2007, 11:25 PM	#3
xoxoxoBruce The future is unwritten Join Date: Oct 2002 Posts: 71,105	What are they in, a dildo? __________________ The descent of man ~ Nixon, Friedman, Reagan, Trump.

03-23-2007, 08:47 PM	#4
richlevy King Of Wishful Thinking Join Date: Jan 2001 Location: Philadelphia Suburbs Posts: 6,669	Is that guy wearing a flak jacket? I hope so. Dendrites? Weren't they the bad guys in Army of Darkness? __________________ Exercise your rights and remember your obligations - VOTE! I have always believed that hope is that stubborn thing inside us that insists, despite all the evidence to the contrary, that something better awaits us so long as we have the courage to keep reaching, to keep working, to keep fighting. -- Barack Hussein Obama

03-24-2007, 01:35 PM	#7
xoxoxoBruce The future is unwritten Join Date: Oct 2002 Posts: 71,105	Yeah, me too. If tw wasn't so busy playing to his lurkers, he could have been helpful. __________________ The descent of man ~ Nixon, Friedman, Reagan, Trump.

03-22-2007, 10:20 PM	#2
SteveDallas Your Bartender Join Date: Jan 2002 Location: Philly Burbs, PA Posts: 7,651	I wonder if it works for dilithium crystals.

03-24-2007, 02:41 AM	#5
tw Read? I only know how to write. Join Date: Jan 2001 Posts: 11,933	Been doing this stuff for a long time. Won't go into details. However a precaution. Do not do that technique to lithium batteries. Unlike NiCds, Lithiums can explode harmfully.

03-26-2007, 01:42 AM	#8
tw Read? I only know how to write. Join Date: Jan 2001 Posts: 11,933	Trick to 'curing' NiCd typically was not performed as in that video. Most don't have a high current low voltage power source. We take a power supply and reverse apply voltage to an offending cell to accomplish same 'burnout'. This problem is more often created by over discharging a series of batteries. Series as in four 1.5 volt batteries makes 6 volts. One weaker battery becomes so discharged that the other batteries actually reverse charge a weak cell. Then the weak cell shorts. Solution was to drive a larger current in reverse across the battery to 'burn out the short'. Then charge each battery separately. Remember weak cells needs more energy. But if rechargeing then all in series, then a weak cell remains weaker. Batteries must be recharged seperately (or in parallel) so that the weak cell can accept more current - more energy. The video did not show that concept and did not show why a weak cell would remain weak; to fail again.

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