timc995

I have a Milwaukee 4Ah battery. After charging it, the charger light is green. Removing and reinserting it, the light immediately shows green again. However, when I press the fuel gague button, only 3 of 4 lights come on. The battery reads 19.75 volts, so I would have expected all 4 lights to come on (my understanding is that the gague is a measurement of voltage, not Ah capacity). Could this just be a burned out LED, or is there another possible explanation?

I know this is an old thread, but thought I'd add my response for posterity. I had this issue on an XC 12.0 battery. It turned out to be a bad connection. I had dropped the battery months before. It worked fine, but then suddenly stopped. As the OP describes, it read fine and 'looked' charged. What had happened was one of the nickel strips had become un-welded from another (it was the main negative terminal in my case). I'm sure it was weakened by the drop, and eventually became totally disconnected. The strips were in contact with each other -- so connection was good enough for a voltage check, but it wouldn't pass enough amperage for the tool to work. I added some solder between those strips, and everything's been working perfect since.