What is a NiCd Battery?
NiCd stands for nickel-cadmium which is a type of rechargeable battery that has been around for a long time. NiCd battery packs are popular because they’re inexpensive, have little memory effect, and you can rebuild power tool battery packs when they go bad. While some manufactures have stopped providing this as an option, it endured as the stopgap platform for cordless systems looking to get rid of the extension cord.
There are several inherent drawbacks with Ni-Cad batteries, particularly in comparison to NiMH battery technology and Lithium-ion battery technology. The biggest drawback being what is called “memory effect.” What happens is if a battery is not fully discharged, and the battery is placed on a charger, it will only charge and discharge to the last charge point. So what can happen in a fairly short period of time is the battery will no longer take a full charge. To combat this negative function, many chargers have a feature that first discharges the battery and then starts a fresh recharge. That takes time, and a typical full battery charging cycle can take anywhere from an hour to three hours for a NiCd battery pack for a power tool. The reason NiCd batteries and told can still be found today is that these types of batteries are comparatively lower priced then other rechargeable batteries—dramatically so. They’re also “dumb”, requiring no electronics or fancy circuits in order to function. Like AA cells in a flashlight or remote control, NiCd batteries just work…until they don’t.