Use 14.4V batteries in a DeWalt 12V Drill?

[Doug Hobkirk]

I have lots of DeWalt 18V XR tools plus two 18V batteries.
I have one DeWalt 12V tool, a drill (XTR I think) that works great plus one 12V battery.
I happened upon two 14.4 DeWalt XR batteries with charger. The batteries fit the 12V drill (after paring off a small tab).


Will I (correct that to "am I likely to) damage my 12V drill by using the 14.4V batteries?



The 14.4 batteries are slightly longer than the 12V but they slip in perfectly and the snaps work just fine. The drill works, but I thought I would ask - my quick test obviously wouldn't test for long term damage.
The 14.4 batteries show about 15V when fully charged (cheap meter) whereas the 12V battery shows a little over 12.
It would be nice to have extra batteries for the XTR drill.


Sometimes you guys respond with comments like: "Oh, yeah, I did that and it exploded and burned my house down." It seems smart to utilize a resource like you.

[Andrew Pitonyak]

My primary reason for responding is to subscribe. That said.... I have seen different advice stating that a DC motor is likely to accept an input power variance from 10 to 25 percent. This puts you directly into the "it might work" category.

If it were me, and, if I did not mind replacing the drill, I would just do it with a fire extinguisher near by. First, I would drill a series of holes into some wood and feel the case to see if I was heating things up. I might expect that you would be more likely to burn out the motor running with a slightly higher voltage. As you state, this will not tell you anything about long term damage. I see a few possible potential problems:



Over heating the motor.
Driving the electronics outside their ratings. So, you might fry some of the internals over time. How flat is the voltage on the 12V batteries, and what is the comparable voltage range on the 14V battery.
If everything does run well, you might over-draw on the 14V batteries and cause premature failure on those by constantly running them below some desired voltage.

[Greg R Bradley]

Are the 12v tools "real" 12v tools that have NiCad or NiMH batteries or the "nonsense" current 12v tools that are really 10.8v LiIon tools labeled "12v max"?

14.4 will have to be LiIon batteries (4x3.6v per cell) that will generally need a compatible charger.

[Doug Hobkirk]

Are the 12v tools "real" 12v tools that have NiCad or NiMH batteries or the "nonsense" current 12v tools that are really 10.8v LiIon tools labeled "12v max"?

14.4 will have to be LiIon batteries (4x3.6v per cell) that will generally need a compatible charger.

What are you actually asking? It seems like you are asking if they are junk tools.



I have told you the actual voltages that I am measuring from charged batteries (actual 12V and 15V observed). My meter is a $5 analog meter, but it's reasonably close. And these voltages are on old, used batteries.
These are all DeWalt XR tools, widespread and very reputable (as far as I know).


If I missed something in your question, let me know and I will reply.

[Jason Roehl]

If anything, your drill will have more power, longer runtime, cooler running, or any combination of the three. It will just be a bit heavier. My 14.4V Porter-Cable NiCd batteries usually measured about 17.4V when they were fully charged. All the voltages are nominal voltages. They're close, but in the end, it's just a name. Heck, in a pinch I once used jumper cables hooked to my work van's battery and a couple nails stuck in the drill to power it when I wasn't done mixing some paint and didn't have time to wait for a battery to charge. The nails were kinda warm when I was done...okay, they were downright HOT, but it worked, and the drill was just fine, though it definitely ran warmer than normal. (I was mixing a ceramic additive into some paint at a client's request--took forever and a day to get it mixed in).

[Loren Woirhaye]

I think it could work fine. After all, those drills are designed to work within a small range of voltages anyway.

I would not consider doing anything clever with Lithium-ion batteries. Good old Nicads are tough batteries though and I haven't read of them catching on fire. As with all batteries, heat is what kills them, so let your packs cool before recharging, no matter what system you're using.

[Greg R Bradley]

What are you actually asking? It seems like you are asking if they are junk tools.



I have told you the actual voltages that I am measuring from charged batteries (actual 12V and 15V observed). My meter is a $5 analog meter, but it's reasonably close. And these voltages are on old, used batteries.
These are all DeWalt XR tools, widespread and very reputable (as far as I know).


If I missed something in your question, let me know and I will reply.
I'm referring to the tool. The NiCad 12v tools are 12v. The newer LiIon tools labeled 12v actually are 10.8v. When Bosch and Makita were the only manufacturers of 3 cell LiIon tools they called them 10.8v tools but then others came out and called them 12v max tools. Bosch and Makita changed their labeling to match the others. All companies now call their 10.8v LiIon tools 12v. So all 12v NiCad tools are running on 12v but all 12v LiIon tools are running on 10.8v.

Running a 12v tool on 14.4v sounds reasonable at 20% higher. Running a 10.8v tool on 14.4v sounds a bit much at 34% higher. You are powering a tool designed for 3 cells with 4 cells. If you think of running your 120v household appliances on 160v, it would be the same percentage overvoltage.

Freshly charged 12v NiCad or 10.8/12v LiIon batteries will measure about 12v either way. A $5 analog meter is probably pretty accurate but in order to measure the voltage of the tool, you would have to measure it while the tool is running.

[Reinis Kanders]

Drill should be ok. Here is a video of some guy running 14.4V drill with 26V battery.
https://www.youtube.com/watch?v=-pb2Z4SokOE

You could open it up and google the specs for the DC motor and switch to be sure.
Make sure you are using appropriate charger.

[Lee Schierer]

I don't know about your 12 volt drill, but they would work just fine in my 14V Dewalt. :D If they don't work for you, I could be interested.....

[Wade Lippman]

FWIW, I have a dewalt vacuum that takes 12,14.4, and 18v batteries.