Convert a battery drill to wall power

Turn an old battery powered drill into a wall power unit.


[Edit]
In the spirt of Instuctables, I'm adding some of the sugestions for improvement and why I didn't do things that way in the first place. Some I had considered, others i had not.

Q. Why not just put in new batteries?
A. Too expensive. The drill was $5 (with case, extra drill and 2 battery packs) and worked for a while. The wall wart was free at another garage sale. Brand new unit would be about $20 and be ready 'out of the box.' A new set of batteries and a charger for them would not be worth the time or money. If it was a good brand name on the other hand...
A. While trying to find out which cells in the battery were live and which were dead, I lost the parts. Thus, no battery shell to reload : )

Q Use a Zener transorb/5 f. capacitor/ect.
A Aint got one. Too expensive to go out and get some just to play with. I don't feel comfortable enough with electronics to risk the parts.

Q Use a more powerful transformer.
A Aint got one. That and i don't know how much I can pump threw the motor before it burns out. I may end up finding a bigger transformer, or trying it on AC current-but not untill I don't need this one any longer.

You may notice a theme here-this is a cheep fix with what I had on hand. Nothing fancy, not a lot of pre-planning to get in the way of getting something finished. Are there better ways to do this? Absolutely : )

Step 1 Research!

wall transformer for project power supply
http://www.instructables.com/id/EQ3VVA5ZVKEYF7HZ0W/
or
Reuse "Wallwart" transformers
http://www.instructables.com/id/EC1BYG2K40EWPKHAGV/
in a perminant way.

How to solder
http://www.instructables.com/id/E30LR180T4EWP872BS/
or
Soldering to large metal objects
http://www.instructables.com/id/EYUBQBN818EWZMIAYA/
if you are lazy like me and decide to solder onto the large battery clips rather than fiddle with the wires inside the case. or, you can't find your soldering gun but can find your butane torch...

you could even use
Handy box from scratch paper
http://www.instructables.com/id/EZO32EAKLOEXCFECUK/
for screws.

and, yes, i screwed up the batteries before i had a chance to use
Revive Nicad Batteries by Zapping with a Welder
http://www.instructables.com/id/EPV474YLF3EV2Z8V9V/
or
Hot Rodding a Power Drill Battery
http://www.instructables.com/id/EZOAB2A75XEV2ZHAQP/

Comments

[codongolev]

I think that after christmas, I'm going to go to Big lots (if you don't know, it's a big cheap stuff store) and get a crappy cordless drill set for 25 dollars. I've had a crappy drill, so I know that the batteries go first, and therefore I am going to convert it to wall power. I'm going to use an 18v power supply for my laptop that died (it has an 18 volt battery- perfect!). as for the battery, I'm going to repurpose it as a battery for a really ghetto electric scooter that I made from an old razor scooter, some lumber, and parts from a power wheels car someone was throwing away. I was able to wire the scooter in parallel, not series so that it goes faster, but it still doesn't go fast, maybe just a little faster than a walk. if I added an 18v battery, though..... (I think I might just add it as a speed boost type thing, like wire it in parallel with some diodes and add a switch... that way the battery won't run out in four seconds).

the reason I say after christmas is because I don't have money currently (well, I do, but I kind of need it for gas and insurance) so I need to get a job and get money. that, and my mom told me I couldn't go in my dad's workshop for the rest of the year because I cannot keep anything clean (cruel and unusual!) so I really can't do anything anyway.

and thus ends the rant of codongolev. have a nice day.

[jtobako]

I've found that the key for power isn't voltage, it's amps. So use the biggest amperage transformer that you can.

[codongolev]

yeah, the computer power supply is 3.9 amps or something ridiculous like that. I think it'll work.

[unasimple]

I've done two drills like this.
One a 12v craftsman drill where I used the 12V 750 mA adapter for the charger that came with it. This one seems underpowered.

For the second one a black and decker 18V I used the biggest adapter (physically as well as voltage) that I could find a 30V 500mA and this one seems to work great. Not sure about longevity though but it hasn't melted yet. :)

[Protractor]

This is a cool project.  I am thinking of doing similar thing to my old Dewalt 12V drill.  I don't have a "wall-wart," but I have an old computer power supply that has a 12V rail and can supply up to 10 A on that rail.  It's rated at 350 Watts max power.  Would using this power supply with a rectifier work?

Crude schematic below:

Wall jack---PC power supply---rectifier---drill

[TheGoodLife]

Thank you for supporting my work through your daily visits to my instructable.

http://the-goodlife.blogspot.com

[jtobako]

You're welcome. But I just have the 'e-mail me' option activated and visit when commented on.

Oh, and the argument was here. Not the first time this has been tried : )

[ewilhelm]

If you really want to tempt fate, try connecting the drill motor directly to AC. There are some permanent magnet motors I've seen in drills that run either on DC or AC at 60 Hz. When you do the test, make sure to use a circuit breaker!

[carpespasm]

For a little more safety you could also throw it on a dimmer switch to drop the voltage. You might still burn up the dimmer though, they're not usually rated for high-draw conditions. It would drop the voltage though.

[csnyder]

You definitely need a rectifier on a permanent magnet drill motor, and if variable speed the controller will fry. Also DEFINITELY need to reduce the voltage. 110 will let the "magic smoke" out of a 14 volt motor in an instant.

[ewilhelm]

For a run-of-the-mill DC motor, that is true. However, the motors in hand-held drills are often designed to run on either 12 volts DC or 120 volts AC, and as jtobako points out are called "universal motors."

[jtobako]

universal motors (ones with brushes i believe) can be run with AC or DC. i saw somewhere that someone was running things like (AC) angle grinders off 3-4 car batteries to get enough voltage instead of springing for an inverter.

[ewilhelm]

That was one of Tim's:
http://www.instructables.com/id/EBLN6A48CVERIE1R92/

[ccconsulting]

I like it.... Now, can it be set up so a dead battery shell can be retro-fitted with an adaptor and a cord to keep the cordless function by switching to a normal battery?

[stone3408]

Yes that is the way mine is set up. Its a 18 volt ryobi. It runs on two 12v batteries in a series, the battery that it came with, or my car. It is a great idea to retro fit a dead battery pack with power jack. Just be careful when you take the pack apart. The batteries usually hold some of the contacts in place inside the pack. A bit of epoxy will solve that problem.

[jtobako]

same idea, just one step removed. you might be able to put the transformer inside the battery shell to retain the original balance.

[gzusphish]

Hmmm....I've got an old Chicago Power Tools drill with a dead battery this would be perfect for.

By the way...if you want to do this instructable but you want a drill which will function at full power you'll have to get an AC adapter (wall-wart) which can at least match if not surpass the original battery's current capability. The one in this instructable was probably trying to draw more current than the wall-wart was capable of providing. Extended peak usage like that may overheat the transformer in the wall-wart and throw a breaker or make a bunch of nice smoke.

As the author said in step one
more voltage with less current = more RPMs with less power
more current with less voltage = more power with less RPMs
also: more voltage AND more current = more RPMs AND more power And overheated drill.

So depending on which power supply you choose you could end up with a really big dremel moto-tool, a really small winch, a pile of molten, smoking slag, or a functioning drill.

The best bet is to stick with a PS that supplies the original battery's voltage and matches or surpasses its current capabilities.

[stone3408]

Yup, I just smoked a wall wart. Two twelve volt batteries from an upc in a series works great though and still portable! It runs great off the car as well.

[eviloverlord]

...Or you could just open the battery unit up and replace the cells with shiny new ones.

[jtobako]

IF you have batteries avalible. this is a 'make-do'. if i had the money for new batteries, i'd rather have a newer, more powerful drill : )

[eviloverlord]

I've just replaces my old 1200maH NiCad drill cells with 2700maH AA cells. While I was at it, I added 2 more to up the voltage from the rated 12V to 14.4V. It now has more than twice the battery life, is more powerful because of the voltage increase and so far seems to have suffered no ill effects from overvolting it slightly. Oh, and the batteries from ebay worked out much cheaper than a new drill, which would still have used nicads and had a poor battery life.

[jtobako]

what did the new charger cost?

[Tracy]

I would recommend either running it off a car battery, or adding a 12 volt gelcell battery or a pack of cheap AA nicads (I solder them together with short pieces of wire, then wrap duck tape around them to make a pack) and use the wallwart to charge the batteries. That will work much better; even a small 12 volt drill motor can easily draw over 30 amps under load.

[jtobako]

Sounds great. Tell you what, I'll send you my address and you can mail me whichever you prefer : ) I didn't have an extra set of batteries, I did have a wall wart. This is about making do. Best would have been to go out and buy a $300 Makitta rechargable-but that aint gunna happen : (

[Tracy]

It's easier for me to just post a link. Here you go. 10 of them at 85 cents each, and you will be able to do more than drill holes in styrofoam with letter drills.

[jtobako]

I wish I was rich like you and could just throw money at a problem. But I'm not and I can't, so I make do.

[Tracy]

In my opinion, spending less than ten bucks to go from 1/10 the power of a Dremel tool (my Dremel is rated 1.15 amp @ 120V) to a full-power drill that's not tied to the wall is a pretty good deal. I dunno, I guess if I never did anything that could actually be considered work, that might be considered "throwing money" at the problem. If that were the case, I would save the $0.000005 that 20 seconds at 16.8 watts of electricity costs, clamp a finish nail in my long-since-paid-for Chinese locking pliers, and bore away.

[jtobako]

You don't understand, when I say "I don't have the money" for something THE CHECK WILL BOUNCE. And that's just not cost effective : )

[Tracy]

(removed by author or community request)

[m_m]

1400 mAh = 1400 mA for an hour, not 1400 mA. A typical drill battery will not run for an hour, meaning that the draw from the battery will be greater than 1400 mA = 1.4A. You should take this into account when picking a power supply (wallwart) because an underrated power supply is a good recipe for disaster (fire).

An Energizer AA battery for example can push up to 2 A continuously (until it is dead).

[smithy813]

so over rated is ok? (like the one used)

[m_m]

the one used is not over rated. It is rated at 1.2A. A drill will pull more than 1.2A, so the power supply is under rated.

[smithy813]

but is over rated ok

[m_m]

yes

[sensoryhouse]

I am going to try this with my Ryobi one+ 18v cordless tools. They are brand new and the batteries are brand new. But how badass would it be to be able to turn any one of my 10 plus Ryobi cordless tools into a wall powered tool. I am guessing an 18 volt 2.5 amp power supply from an old laptop or printer will do the trick (ebay). I will take an old battery apart, place the power supply inside the battery casing. Then I will be able to quickly plug-and-play the power cord into any tool. I have taken apart about half of my tools and they all have "18 volt" written on the actual motors. ANYTHING I NEED TO KNOW? ANY POINTERS? PLEASE HELP!

[Stryker]

Damn it, I just thought of this exact same idea. I was all excited to invent this until I found this instructable. Anyway thanks for the good write up, I'm going to try to make one anyway.

[jtobako]

Just what's here and in the comments : )

[!Andrew_Modder!]

i tried this and it didnt work for some reason!!! (i used 1000mah, dc AND ac...).... errg... (yes i had the right polarity.) lahh

[jtobako]

What, exactly, does the power supply say-and are you sure the power supply and drill worked to start with?

[!Andrew_Modder!]

9.6v dc (w ac switch), 1000mah. i used it in a 9.6v cordless drill (used aligator clips for contacts in the drill handle). and i no the power supply works, because i use it a lot for random things, lol, and also tested it with a multimeter. And for the drill, ya it works cause i took the battery out and tried it w dc (batterys are dc), then tried it with ac, did not work, so i put the battery back in and it works w battery still, but no addapter...... :-|....