Rechargeable NiCad batteries should be replaced with a new battery when they no longer recharge, or they only hold a charge for a brief period. Under normal household use, most rechargeable batteries will last approximately 3-5 years. This assumes that the batteries are cared for and charged in accordance with the recommendations outlined in the Use and Care Guide supplied with the tool and/or battery when purchased. Failure to follow the recommendations for charging and care of the batteries will greatly diminish the useful life of the batteries.
If you have questions as to the proper care and charging of your Black & Decker NiCad batteries, please call us at 800-544-6986, and we will gladly assist you.