Ni-Cad Rejuvinator

There are ?

Graham

Google it

I believe you can pulse each cell with a high current pulse (charged up cap?) to burn away tiny dendrites that form fron low current use.

Try "zapping NICADs" and you should get something

yes, you have to open the "battery" to get to the connection to each of the ten? "cells" inside...

I rejuv cells by connecting them to a 12 V 10Amp supply for a few seconds.... they draw lots of current and clear out whatever is shorting them inside... then charge as normal...

they work again , but never as well as orignally...

Mark

Something like this:

+V ---[R]---+ +--------+ | | | | | | o o | SW \\ [NICAD] *cell*, not pack o | | | [C] | | | Gnd -----------+-----------+

Make C as big as you can, size R to limit inrush. Transfer the switch to discharge the cap into the cell.

I experimented with this a whole bunch of years ago. As I *dimly* recall, I didn't get better results by increasing C beyond 36,000 uF, nor did I see any benefit going above about 24 V. However, those numbers might as well be pulled from a hat. The one number I do remember was a little better than 30 % "success". The problem was, that the success was very short lived. I was able to rejuvinate the shorted cells, but they would re-short in a couple of days. I ended up abandoning the thing as useless, and found a much better technique: buy new cells.

Ed

That is only step 1. Next you deep cycle it a few times, paying attention to not overheat them. Finally charge them up slowly and leave on trickle for 3 hours.

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JosephKK

Definitely! They are usually for specific types of batteries (AA, C, etc.). I need a circuit for more general use.

g_no

Tried that with no success, thanks