Effect of Zapping Nickel-cadmium

Remote control (RC) enthusiasts are experimenting with all imaginable methods to maximize battery performance. A racecar motor draws 30A for about four minutes delivered by a 7.2V battery. This amounts to over 200W of power, a large amount from a small battery. An experimental technique that seems to enhance power is zapping the cells with a very high pulse current. This is said to increase the cell voltage slightly and generate more power.

According to experts, zapping works best with NiCd cells. NiMH cells have been tried but do not produce consistent results. Companies specializing in zapping use a very high quality NiCd cell from Japan, and the sub-C is the most popular size for this application. The factory handpicks the cells and they come with a unique label in a fully discharged state. When measuring a totally empty cell (no charge), the open circuit voltage should read between 1.11 and 1.12V. If the voltage is lower than 1.06V, then the cell is considered suspect and zapping does not enhance the performance as well as with the others.

To zap a NiCd battery, a 47,000mF capacitor is charged to 90V, after which the raw power is discharged directly across a single NiCd cell of 1.2V. After the shock treatment, the cell is cycled and then zapped once more. Experts say that once a cell is treated and used in service, zapping will no longer improve performance, nor does it regenerate a weak cell.

The voltage increase on a successfully zapped battery is between 20 and 40mV when loaded with 30A. According to experts, the voltage gain is permanent, but there is a small drop in the gained voltage with usage and time.

There are no apparent side effects from zapping, however, the battery manufacturers remain silent about this treatment. No scientific explanations are available as to why zapping improves battery performance other than the belief that it lowers the internal resistance. There is little information available regarding the longevity of the cells after the treatment. Zapping only seems to work with high-quality standard NiCd cells, and in no way should this be used on lithium-based chemistries.

Another method to improve NiCd batteries is through a recondition program. Tests performed at the Cadex laboratories reveal a permanent capacity gain of about seven percent when servicing new NiCd with recondition, a program that lowers the battery voltage to 0.4V/cell on a secondary discharge. This capacity gain is not fully understood, other than to assume that the battery improved through additional formatting. Another explanation is the presence of early memory. Since new batteries are stored with some charge, the self-discharge that occurs during storage may contribute to the buildup of crystalline formation, which recondition reverses. While NiCds once played a pivotal role for RC enthusiasts, the interest is shifting towards high-performance Li-ion.

Comments

On February 4, 2011 at 2:02pm
maghsoud safari javid wrote:

how we can zapping lead acid battery?

On April 7, 2011 at 8:24am
pankaj wrote:

is i can increase the power of battery by apply some pressure in battery shell ?

On April 13, 2012 at 10:31pm
Mostafa Fayezi wrote:

I want to know about battery
thank you

On April 13, 2012 at 10:36pm
Mostafa Fayezi wrote:

in my power plant we have about 1500 plante battery so I want to know more about them

On April 25, 2012 at 1:46pm
robert leiker wrote:

love your info

On May 15, 2012 at 12:51pm
ron davison wrote:

Does this work on people?
smile