Electrical Wiring in the Home/drills


I have a 12 volt drill that needs batteries.  Been ready some things on the web and ran across some interesting ideas- leading to my question.  Can I take an ordinary ac/dc converter, such as  used on a charger for another small appliance and hook it directly to the two terminals on the drill, and plug it in.  Will it work, making it a direct hookup from a light receptacle?  From what I have read it makes me think it will.  Any ideas?  Thanks, Richard

Richard      I see where you are going,  and a bit of basic electricity will help,     the drill is designed to use a certain amount of power,  consistently,     included in that power is voltage   12 volts DC  with a certain amount of tolerance,  maybe plus or minus 10%  it depends on the tool,  so the motor is expecting 12 volts within the tolerances,  too low no go, possible damage,  too high possible damage,     

The problem with an ordinary converter   such as a laptop type external converter is you need to match not only the voltage  but the amperage    measured in amps or micro amps,  if you look at 10 power supplies you will see some with the same voltage on the output but rarely the same amount of potential current,     

One might be 200 micro amps,   some 900    some  several amps,       micro is

How many microamps in 1 amp? The answer is 1000000.
We assume you are converting between microampere and ampere.
You can view more details on each measurement unit:
microamps or amp
The SI base unit for electric current is the ampere.
1 ampere is equal to 1000000 microamps, or 1 amp.
Note that rounding errors may occur, so always check the results.
Use this page to learn how to convert between microamperes and amperes.
Type in your own numbers in the form to convert the units!

from website      http://www.convertunits.com/from/microamps/to/amp

Two problems   the supply must be capable of supplying the rated voltage in a constant state,   also  because you are talking a drill you are talking a motor,    the motor will not work hard just spinning, but drill into a knot and the motor is doing all it can to push the bit through the load,   

Next problem, is the motor and drill designed to see pure DC like out of a battery or can it use rectified AC    which is basically taking the AC and changing it to DC        some motors are specifically designed for pure DC others do not like converted AC, and how you would find that out will be a problem    because I am sure their design is proprietary,      

So you would need more than a ORDINARY power supply,  you would need one that matches the battery capacity,  and voltage,      are the batteries standard or built for the drill?

Like a car battery  you can get 500 cranking hours,   700  so on     a way they label the power available in a particular battery,  the higher the crank amps,  [full load bearing down on a cold engine needing all the power it can produce]

So the design of the drill is for certain power rated 12 volt batteries, maybe off the shelf, type   a bunch of D batteries  or a special battery for the drill,   I cannot say from here,   

Bottom line is if you can find a supply that can produce the same power as the battery or batteries that are in it,     a supply that can hold up during changing loads,     yes you can use a power supply,    

But like a battery charger   you can find a battery charger that takes 30 minutes,   then there are chargers that "mind" the battery  say for a stored car or some device to keep a trickle on it,   all the same voltage   but huge differences in power,      

Then you see expensive chargers that have starting capability       many will say  do not try to start an engine or some such language with this charger,    the in rush current will be too high for the guts of the device,          

So you need to know if the unit needs clean dc,  if it can be run off rectified DC,    and you need to know the capacity it needs,    and on short bursts  when like the example of a knot in some wood might occur,    

YES  I see what where you are going, but just some 12 volt  "charger" is not a power supply   two different things,   

YOU need a power supply    a battery is a power supply,          

Once you match all that up,   yes a power supply will work,     not a trickle charger   a power supply   they look the same in some cases   most are chargers,     chargers put power in the battery over time    you want instant power,    that is the difference,      

Maybe consider a battery charger with spare set of batteries,      that would be ideal and how many cordless tools work,  one battery in the charger one in the device,     

It would be a good learning experience, but beware,  a charger on a drill and a load to the bit,  may just blow the hell out of both,          

So you need to match the capacity of both and the new device should match the battery capacity   voltage is not the only thing you need,  

Our shop is repair@mearservice.com   phone is 816-650-4030   if we can help by phone or email   give us a call or drop us a note,  
About Electrical Wiring in the Home
This site answers questions related to home electrical wiring, home wiring, general electrical help,and other electrical questions related to aleternating current (AC). You can find help on the National Electical Code, home electrical issues, wiring electrical outlets, installing lighting, electrical grounding, and general electrical help for do-it-yourself projects not require an electrician. If you do not see your home electrical wiring question answered in this area then please ask your electrical wiring question here

Electrical Wiring in the Home

All Answers

Answers by Expert:

Ask Experts


Will Babbitt


Electrical issues of all types, wiring, control, appliances, components, specialty in Electric MOTOR or APPARATUS trouble shooting, electric motors, electrical problems, single phase, three phase, DC, capacitors, elevator MG-Sets, modifications, reverse engineering, VFD Drives, single to three phase convertors. Repair of most any electrical/mechanical/electronic apparatus, OEM, AC, DC, Industrial Applications, Three phase, single phase failure mode, determining the root cause of the equipment failure BEFORE failure repeats, Antique appliances, electric motors, fans, ceiling fans, base mount fans, poor equipment performance, Modifications, habitual failures, vibration, redesign, obsolete issues, collectible items restored, rewinding. Owner of EMR Repair Inc www.emrrepair.com More information on electric motors, under Engineering/Motors Ask about any electrical or mechanical problems in the home, office, or even at your work. B2B or business to business CONSULTING I can do but it would be a much more complex issue, that would require a significant amount of time. repair@mearservice.com from there we can discuss and begin work on about anything. Industrial electric motors, controls, troubleshooting, vibration, alignment, any type of industrial or commercial electric/electrcical equipment For the home owner, renter, apartment if you have odd things going on, describe to me, photos are normally very helpful, appliances, heating and air conditioning issues, light switches, installation, DIY PROJECTS FOR THOSE NOT EDUCATED IN ELECTRICAL, we can do some things, but for safety and sanity reasons, I may refer you to a local electrician, and help you find one, help you with pricing and even speak directly with anyone you hire if you have issues,


Over thirty years with a major repair and sales company, VP of Operations, and former owner of my own specialty repair shops, MEAR Services local to Kansas City Missouri EMR Repair Inc., located in Kansas City Missouri, 2014 sold both businesses to JCI Industries, Lee's Summit Missouri wbabbitt@jciind.com Evaluation and repair of electrical/mechanical apparatus. Electrical and mechanical repairs, trouble shooting including, vibration and balance issues. About.com provides this service, and the huge costs to provide help on about any subject. They provide the servers, the people to vet the experts, costs that would be the same as operating a good sized business, They should be appreciated for what they do, the huge costs and the great help they provide for free, Electric motor questions, can be answered here but there is a dedicated category that has other experts to help and add to a solution. Other common questions, are noises in the walls, breakers tripping, devices not starting or shutting down for no apparent reason, smoke alarms buzzing, thermostat change outs, or sizing wire or needing information for a new project, but anything can be resolved, anything, with enough effort and patience, DIY, with electrical is possible, but in most cases the use of a simple ohm meter or volt meter is needed, they can be purchased at any hardware store for a few bucks. If you have smoke, or smell smoke, don't be writing me, call 911 the Fire Department has no problem looking for smoke smells, better then spraying water on a blazing fire. DO NOT GET CAUGHT INVESTIGATING AND TRAPPED IN A BASEMENT LOOKING FOR A BLOWER FAILING< As to the tip jar, it is up to you, it is appreciated, every expert spends out of pocket that I know, we spend on IP time, computer wear, printing documents, books, and of course our time, but if we prevent a $400 service call, we did well,

Former IBEW, EASA, IEEE, UL, ..............


10 plus years, various Technical Schools, followed by Industrial College Credit and non Credit Courses, electronics courses, experience in most any electrical apparatus, electric motors and generators, AC OR DC, fractional to above 5000HP, other electrical apparatus, slip rings, sleeve [plain] bearings, lubrication, identification-no data plate, control components, service and sales. I have continued night schools for decades, the list is extensive. I have been in the business of repairing most anything with wires or mechanical parts for decades, I have some helpful hints and directions you won't have to dig up. Or hopefully not have to pay a huge service call invoice to find.

Awards and Honors

Past/Present Clients
Federal Government, National Weather Service, NOAA, Commercial Power Plants, Major Vehicle Manufacturers, Printers, Other industrial and Commercial Businesses

©2017 About.com. All rights reserved.