Nickel Metal Hydride Batteries; It's About Time

Every industrial hygienist at one time or another has felt the bite of nickel-cadmium batteries. Certainly the venerable NiCad power source has served us well in every king of industrial hygiene instrument from personal monitoring pumps to multi-gas monitors. They are lightweight, reusable and predictable enough, but there is always that down side. There are the memory problems and the lazy battery issue. Then came the environmental concern over cadmium, and it suddenly became expensive to dispose of them. But we lived with these liabilities because we had to. The NiCad battery became the battery that we all loved to hate.

The lazy battery problem is the most frustrating for users of personal monitoring pumps. A pump could be working fine, running consistently for eight-hour samples, and then placed into storage. Several months go by and suddenly there is a need to sample on short notice. The pump is fully charged overnight and then proceeds to die after just six hours.