Wednesday, November 29, 2023


How to fix drill batteries that won’t charge

By Cheri Sicard
The video below from Flannel Guy DIY has over 2.4 million views. Needing to know how to fix drill batteries that won’t charge must be a common problem, and since drills are such an essential RV tool this is also likely a common RV problem.

The tips in the video will work for 20v, 18v or almost any lithium battery for your tools. It works for DeWalt, Makita, Milwaukee, Ryobi, Black & Decker, Rigid, and more.

Will it always work? No, but it merits trying before tossing or replacing a battery that still might work.

The demonstration begins by comparing a good battery versus one that won’t charge and how they react on a charger.

Of course, the defective battery will not power the tool and will not charge when connected to the charger.

What our host discovered is that for a battery to charge, it must have a little power left in it to send a signal to the charger that it needs to be charged. If your battery is completely dead, it can’t send the signal that triggers the charge and therefore nothing happens and you think the battery is defective. But it might not be!

To find out, you have to give the battery a bit of a jump-start.

How do you do that? Watch the demonstration in the video as it will be more beneficial than me describing it. But judging from the nearly 1,800 comments on the video, the technique works and it may save you from having to buy another battery.

In the video demo, it worked perfectly. A short jump-start of the dead battery and it started charging again, as always. Watch as he demos with two different style batteries.



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Cancelproof (@guest_260487)
17 days ago

Great tip. Great advice. Thanks for bringing this to us Cheri. Well done.

Bill (@guest_260386)
17 days ago

Don’t “throw them in the garbage.” Take them to Lowes or HD and recycle. You can throw alkalines in the trash.

Bob W (@guest_260311)
18 days ago

Hey Powerless, I used a dc converter from some broken gizmo I had. I cut off the plug and installed alligator clips on the wires.Must be the same voltage and must connect properly. But it will put a charge in your dead batteries to allow the regular charger to take over.

Joe (@guest_259912)
22 days ago

As chargers and batteries become more sophisticated this is less likely to work. This didn’t work on a DeWalt 18v battery. Replacing the bad cell didn’t work either. Apparently the failure was somehow locked into the chip.

Powerless (@guest_259489)
24 days ago

I have 2 dead batteries, so nothing to jumpstart with. Can I use another type of battery?

Split Shaft (@guest_259269)
25 days ago

Another great tip, do not store a tool battery in a discharged state. Many cordless power tools come with two rechargeable batteries. Some folks will use the tool, even swap a battery that stopped powering the tool and put the discharged battery back in the tool bag for the next time the tool is used only to find out the discharged battery they put away will no longer accept a charge because the cells discharged below the cutoff point of being able to be recharged. Then jump-starting a dead battery likely will not be necessary when batteries are stored in a charged state. Some lithium batteries will go into a protect mode to prevent their recharging if their voltage falls too low.

Bill Byerly (@guest_259261)
25 days ago

Great money saving tip! Thanks for sharing!!

Bob W (@guest_259243)
25 days ago

When I first saw this, I did not want to risk wrecking a good battery to put a charge into the dead one. Also, I did not have another good 18v battery. So, I went to my junk drawer and found an old 18v power converter that I had from some other broken gizmo. I hooked up the converter to the dead battery and allowed it to charge awhile. It then would accept a charge on the proper charger I had for that battery. Same principle, just a different means to do it.

Roger V. (@guest_259226)
25 days ago

Great tip! Thanks!

Bob (@guest_259223)
25 days ago

This may not work for the some newer lithium batteries since the battery has a ‘battery management system’ built in. However, the newer batteries should not drain completely. The BMS will shut the battery down while using it and it reaches a minimum charge state. The batteries consist of multiple 1.2 volt batteries, and if one of these fail, the battery will not be able to fully charge even though the charger shows full charge.

Tommy Molnar (@guest_259222)
25 days ago

Thanks for finding and sharing this, Cheri. It’s pure genius. Well, almost . . .

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