Gwerner74
Senior Member
Since I'm sure I'm not the only one here that uses Craftsman 20V cordless tools, whether it be in the shop or for yard tools, I figured I'd share this. This weekend I ran into an issue where I pulled a battery off the charger, slapped it into a tool and the tool didn't work. Tried a few different tools and same result. Battery charge indicator showed full, but no joy. It was late so I set it aside for the night. Checked the battery the next day in the same tools and they all worked, so thought we're good and it was a random fluke/charging error that cleared itself. Then pulled a different battery off the same charger and popped it into the same tools, all no worky.
I immediately knew that the charger was faulty and was overcharging the battery and triggering the internal protection circuit. This time though, the battery didn't reset itself after sitting for almost 48 hours so I feared that this 6.0 Ah battery was bricked. Then I noticed that when it was attached to my 3/8 ratchet, even though the tool wouldn't run, the LED light did turn on. Quick web search revealed that when these batteries go into the fail-safe mode, they can be discharged to reset them if you connect them to a flashlight, apparently it's the only tool that will discharge them when in this protection mode. Went and grabbed the cheapest Craftsman 20V flashlight and let it run for about 30 minutes and boom, battery is back in action on every tool. So a $35 flashlight (that is actually pretty convenient to have now) reset the battery that would have been $130 to get a new one. Hopefully this helps someone along the way...
EDIT: This same type of reset procedure will likely work on any brand of rechargeable tool battery since there's really only a handful of lithium-ion battery pack manufacturers out there and they're all using the same basic design.
I immediately knew that the charger was faulty and was overcharging the battery and triggering the internal protection circuit. This time though, the battery didn't reset itself after sitting for almost 48 hours so I feared that this 6.0 Ah battery was bricked. Then I noticed that when it was attached to my 3/8 ratchet, even though the tool wouldn't run, the LED light did turn on. Quick web search revealed that when these batteries go into the fail-safe mode, they can be discharged to reset them if you connect them to a flashlight, apparently it's the only tool that will discharge them when in this protection mode. Went and grabbed the cheapest Craftsman 20V flashlight and let it run for about 30 minutes and boom, battery is back in action on every tool. So a $35 flashlight (that is actually pretty convenient to have now) reset the battery that would have been $130 to get a new one. Hopefully this helps someone along the way...
EDIT: This same type of reset procedure will likely work on any brand of rechargeable tool battery since there's really only a handful of lithium-ion battery pack manufacturers out there and they're all using the same basic design.
Last edited:
