Tenergy D Size 5000mAh NiCd Rechargeable Batteries with Button Top - 16 Pack for Flashlights, Toys, and Emergency Power Backup

Over the years nicad batteries have received a bad reputation. I have found them to be very reliable and tougher than nails if cared for properly. They like to be cycled. Charged to full capacity and discharged completely, then charged to full capacity again. You can turn on and off whatever device they are powering as many times as you like, but just make sure they are mostly discharged before charging them again. Nicads do not do well with being topped off. Cycle them completely and they will serve you well. I have also found that they perform better over time if stored in a slightly discharged state. They can withstand high drain rates, high heat, quick charging and overcharging better than any other battery chemistry I have dealt with. If heavy use is your game, these batteries will claim their fame. I use these in lights, lanterns and boomboxes. They never let me down. Not even in the heat of the summer desert. I recently found a set of 4 aa nicads that had been sitting in the back of my toolbox for three or so years. I charged them up and put them back into service and they have been performing perfectly for almost two years. I highly recommend, especially for extreme use.Update: I have had one cell / battery fail completely. Will not take even a slight charge from my manual charger. Other people have had the same problem. I am going to attempt to contact the company / supplier directly as others have. So far, they have been good about replacing any defective cells for those who contacted them. Will see what the outcome is and post another update when I can.