I have a Hi-Spec 18V Drill Driver. Has an LI-ION battery. I took it out today to charge the battery and it’s not even registering on the charger. The charger has one green light on and the other light stays dark no matter if the battery is plugged in or not. When I put it into the drill, the drill won’t work but the LED work light flashes a couple of times. It’s about 3 years old. Any ideas why it isn’t working?