hey guys one of my 901 batteries has been acting up for a while and after toying with it for a while i figuered out the issue but first ill tell you what it was doing it would work when i hit it but it had to be a realy hard drag like my neck would hurt trying to rip this so i tried hitting it on my knee led light faced up .. that didnt work i tried blowing through it led side and nothing .. so then i removed the led cap took a paper clip straightened it out and then i worked around the led and pushes the battery down as far as it would go and now my battery is hitting like it is brand new so if you gotta take realy hard drags to activiate your battery all you gottas do is remove the led cap take a paper clip and push your battery down and it should work better =]=]