Never before have I been so disappointed in a battery. I bought this battery in October and here it is only January and it hardly works anymore. No warning..just shuts off and takes over 9 hrs just to get a full charge which it doesn't even indicate when it's fully charged any more. With only having 1 month warranty on it I won't even consider buying another one. Very very disappointed as it cost me over $40 for one and my cheap Ego ones I've had for six months and still going strong. Before you ask...yes I've tried it on different chargers, no the threads and heads are not dirty etc etc. It's just the battery.