Archived from the Tools In Action forum (Dewalt). This thread is read-only.
I have a set of 18 volt DeWalt batteries DC9099 to be exact, came with a combo kit of drill driver, flashlight and sawz all. Well I charge them weekly for use. They take an hour to charge I believe. Well I notice one of them is weak, you can definitely tell by use just from listening to how the tool works. I’ve used both batteries and you can tell which one is the strong battery and which is weak. Have to mark them so I know.
Could this be from charging them too much or do these batteries just slowly kill themselves? Yesterday needed to use them and even after charging them both in the morning. Good one stayed fine, but other one I ended up having to charge it again, got it up to charged and it still was weak.
Is this just a battery going south or what?
Lithium batteries have no memory so u can charge them even when half full..I’ve been told that you shouldn’t squeeze every last ounce of power out of the battery or should I say,get that last screw with what little power is left,batteries today are intelligent and need abit of power to tell the charger what state there in and if there’s isn’t any charge left itl have adverse effects on your pack..hope any of that helps