10.3 The Effect of Zapping
To maximize battery performance, remote control (RC) racing enthusiasts have experimented with all imaginable methods available. One technique that seems to work is zapping the cells with a very high pulse current. Zapping is said to increase the cell voltage slightly, generating more power.
Typically, the racecar motor draws 30A, delivered by a 7.2V battery. This calculates to over 200W of power. The battery must endure a race lasting about four minutes.
According to experts, zapping works best with NiCd cells. NiMH cells have been tried but they have shown inconsistent results.
Companies specializing in zapping NiCd for RC racing use a very high quality Japanese NiCd cell. The cells are normally sub-C in size and are handpicked at the factory for the application. Specially labeled, the cells are delivered in a discharged state. When measuring the cell in empty state-of-charge (SoC), the voltage typically reads between 1.11 to 1.12V. If the voltage drops lower than 1.06V, the cell is considered suspect and zapping does not seem to enhance the performance as well as on the others.
The zapping is done with a 47,000mF capacitor that is charged to 90V. Best results are achieved if the battery is cycled twice after treatment, then is zapped again. After the battery has been in service for a while, zapping no longer seems to improve the cell’s performance. Neither does zapping regenerate a cell that has become weak.
The voltage increase on a properly zapped battery is between 20 and 40mV. This improvement is measured under a load of 30A. According to experts, the voltage gain is permanent but there is a small drop with usage and age.
There are no apparent side effects in zapping, however, the battery manufacturers remain silent about this treatment. No scientific explanations are available why the method of zapping improves battery performance. There is little information available regarding the longevity of the cells after they have been zapped.