Do NiCd batteries really have a memory effect? Answering this question is a sure way to start a flame war on the internet. The simple answer is: Technically speaking NiCd batteries do not have a memory effect. However, they do suffer from a voltage depletion phenomenon that most people call the memory effect. So practically speaking, NiCd batteries do suffer from a memory effect, even if it is not technically correct to call it that. Fortunately, the voltage depletion effect is reversible by conditioning NiCds. If you use NiCd batteries you should be aware that most the problems experienced by NiCd battery users are not due to a "memory effect" but are due to overcharging. Overcharging is usually caused by poorly designed first generation battery chargers. These chargers continue to deliver current to the batteries even after the batteries are full charged. "5- hour" and "8-hour" chargers can easily damage NiCd or NiMH batteries. The big difference between voltage depletion, the "memory effect" and damage caused by overcharging, is that reduced capacity due to overcharging is not reversible. -source: greenbatteries.com