Introduction: Jump-Start Your Car With Drill's Battery

Picture of Jump-Start Your Car With Drill's Battery

My car's battery was dues to be changed. Every time I started the car, I could hear that one day it will not start.

Monday morning, I have an important meeting at 9:00. I am ready to leave my house, but I can't start the car.

Battery does not have enough juice. In the area I live, there are no cars around. I could ring my friend to give me a lift or a jump-start, but it will take at least 40 minutes.

There is no way I can push-start my car.

Time is running out. I go inside and pull out the battery from my drill.

It's 12v battery, just like my car's.

I tape 2 screws to the batteries + - terminals.

I connect the both batteries together using jump leads.

I wait 10 minutes before trying to start my car. After 10 minutes, I manage to start my car.

Let's go to the meeting and on the way back, pick up a new battery.

I got lucky this time.

A made up story, but it could be real :)


This little trick should work the best if:

  • Your drills battery is charged, big capacity and the same voltage as car's battery or a little bit higher.

I used 12v drill battery to hook it with my 12v car's battery. I believe it should be fine to connect 14v, 16v battery, but I am not 100% sure at what point do you cross the line, putting your car's electronics at danger. That's why I recommend using the same voltage battery. If you know the answer, please let me know in comments.

  • Your car's battery is not completely dead.
  • If you own a small car with a small battery.

It's not the smartest thing to do, so only try it out if there is no other way. There is always a small chance of destroying your drills battery or messing up your cars electronics. 99% of times nothing bad will happen, but let's put it that way. I would not jump-start my "Porche" this way.

Step 1:

Picture of

  • Pull out the battery from your drill.
  • Tape 2 screws to battery terminals.
  • Connect both batteries together using a jump lead.

Positive to positive, Negative to Negative.

  • Let batteries to sit for around 10 minutes or more.

  • After 10 minutes, try to start your car.

You have 2 options.

To disconnect the battery and try to start the car or leave the battery connected and start the car.

Leaving drills battery connected should give better results, but could damage it.

I only waited 8 minutes before trying to start my car. I expected for the engine to struggle, but it did not.

Car started - Ouu Yeah!

Here is another reason to keep your drill's battery charged!


zeppelingirl (author)2016-10-06

very cool. I LIke it

terrefirma (author)2016-10-06

I once bought an old BMW 7 series from my neighbor- computer in the trunk, one of the first on board GPS, etc. One of the accessories was a little battery charger that plugged into the cigarette lighter, with a long cord and little terminal connectors. I never used it but always wondered...

bmalek (author)2014-11-14

Or you could have taken off your alternator belt and use the drill + socket to spin the alternator.

ShakeTheFuture (author)bmalek2014-11-14

I don't think my drill could spin it. Maybe with something more powerful. That's a good idea though.

bmalek (author)ShakeTheFuture2014-11-15

Without the belt on, you can spin it with your hand. Maybe I'll add an instructable for this. The problem is clearance, I don't know if there is room on modern cars.

noahspurrier (author)bmalek2014-11-20

Three points against your plan... First, an alternator needs a minimum of 2000 RPM to start to give enough voltage and current to charge a battery. That's over the max RPM a cordless drill will spin (some might do 2000 RPM, max). Second, it's very inefficient. You would be taking a electricity from a battery and converting it to mechanical energy of the spinning drill; you'd then transfer mechanical energy to the alternator which would take this mechanical energy and convert it back to electricity to charge a battery. You would be better off off using the drill batteries to charge the car battery as this article suggests. Third, the alternator may spin freely while off the serpentine belt and with no electrical load, but as soon as you attach a heavy load (like charging the battery) the alternator is going to resist and and I'd be surprised if a cordless drill had enough torque to keep the alternator spinning, If it could still spin it would certainly be much lower than 2ooo RPM. More likely the overload detector will shut off the drill (most Lithium Ion drills these days have overload detectors to protect the batteries).

TifftonyL (author)noahspurrier2016-09-10

My husband swears he can jump a car off with a drill batterie i not found where anyone says it can be done but soon will find out any min but im a girk and i know nothing about cars i thought blinkers needed fluide and i put oil down my dip stick one time so he can pull one over on me and i never know

MSawyer (author)ShakeTheFuture2014-11-20

You can't get more energy out than there is in the drill battery no mater how you transfer .

denbecr (author)bmalek2015-05-24

Not nearly enough RPM that way.

ontopofit (author)denbecr2015-12-08

Sure there are. if you use an impact driver there is enough RPM

papatait (author)2016-01-03

Read a number of comments,and they were interesting. some good and some not so good. As being a mechanic and truck and construction equipment operator most of my life, I can relate to the problem of starting older and newer equipment. older equipment is easier to start, just get it to roll over and have some spark and it will run. newer is more finicky, the computers/electronic ignitions shut down at about 10volts. the starter can draw the voltage from them with a low battery it may turn over but have no spark.the newer trucks have similar problems they are now computer controlled, no more put it on manual and tow a dead truck to start All highway trucks in the united states, other than military trucks are 12 Volt, some use 24 Volt to start but most use 12 Volt to start. most construction equipment used 24 volts.

Just my overations over 70 years

Orngrimm (author)2014-11-14

cool trick!

And it cannot be stressed enough:
NEGATIVE TO NEGATIVE (black, often car-body)

if you do it like + to - it will create massive sparks, local plasma, redhot metals, options for loosing fingers (burn thru) and most probably a dead car.

bat159 (author)Orngrimm2014-12-04

It can also cause the vehicle batteries to overheat and explosively vent the acid. Personal experience, no fun not knowing how well (or if) your eyes will work for several weeks.

mykiscool (author)bat1592015-09-07

And can ruin a $1000+ computer

Orngrimm (author)bat1592014-12-06

Shocked to hear that! But you hopefully recovered well?

tsturtevant (author)Orngrimm2015-08-27

About ten years ago I was a Safety Instructor at a Nat'l Auto Auction company. At that time statistics showed the the number one cause of blindness in North America was jump starting a car improperly. Safety glasses are inexpensive. Store them with your cables. We had one car battery explode inside a garage and shot a section of the battery through the metal roof. Be careful.

mh76dk (author)Orngrimm2014-11-14

You made it sound so great and then ruined it with the whole losing fingers/dead car part... ;-)

ShakeTheFuture (author)mh76dk2014-11-14

That's if you connect + to -, what you don't do - ever! :)

vader406 (author)ShakeTheFuture2014-11-15

But it makes so much sense if you think of + and - as female and male!

ShakeTheFuture (author)vader4062014-11-15

Lol, that's true :)

Kafukai (author)Orngrimm2014-11-14

When I was jump start on my 1st attempt I was did it, and I was burnt my main car fuse, I was able to solder it the coil, but I was bought a new one it was cost me 25$ USD.

ShakeTheFuture (author)Orngrimm2014-11-14


What do you think is the highest drill batteries voltage, that is safe to use for 12v car battery?

DanielS64 (author)2015-07-24

Why not do the same thing, but with the charging base instead of the battery? That way you'd get a constant stream of 12v power instead of a waning source?

Is there a reason?

ShakeTheFuture (author)DanielS642015-07-26

My car was parked in the public car park, so there was no socket where I could plug the charger. It was a real life situation. I did not feel like asking somebody to give me jump start. So I just went home and took the battery from a drill.

tdzurnak (author)2015-02-18

dude,,that's cool...i'll have to try that...damn cold weather is killin my battery...

russ_hensel (author)2015-02-06

Just a note to let you know I have added this to the collection: Cordless Drills Hacking for Other Uses !


Take a look at a bunch of project involving odd uses of drills.

and for even more drill info


technosasquatch (author)2015-02-03

Just had to use your neat trick today, I was dumb and left my headlights on.


What kind of car was it? How long did you wait until trying to start the it?

Makedo (author)2014-11-30

all of the new cars are very touchy when being jumped. some jump boxes have filtered power as do most tow trucks. with out it you fry the computers and solid state batteries . jumping from one car to another is no longer a good idea. most alternators are made in china and are defective when producing clean current. things can catch fire, melt down or go boom. the out put needs to be regulated in most cases. also never store a battery on the ground even for a few minutes. the earth will ground the battery and it will loose its ability to hold a charge. put the battery on a rubber mat or on some wood.

KROKKENOSTER (author)2014-11-25

This is very neat if the battery of the car is not "Dead"or completely discharged or "Flat". Just one comment Do not tear the electrical tape off the way that you did but CUT it off. The reason being if you want to insulate an electrical connection the tape looses its cling ability after a relatively short time as the plastic is streched and still under strain .After you did cut it rub it with your hand as its it called "Pressure sensitive tape"then the insulation will last a lot longer before becoming loose.

Thanks, great tip. I never thought about it.

Jose EribertoP (author)2014-11-21

You don't need to wait for 10 mins to charge your car's "weak" battery. After plugging it on, start it right away. Nothing will happen. Trust me. I used to work in an autoshop. Once car has started, take out the donor battery right away. All you need is just to power up the spark plugs. Actually, the video here for a so-called dead battery isn't dead at all! Why? All his dash lights went on. There's just not enough juice to give the spark plugs to ignite.

lambsb (author)Jose EribertoP2014-11-24

Your forgetting about having to crank the engine. Spark plugs will not even fire unless the engine is rotating, filling the cylinders with air/fuel mixture, and turning the distributor or crank sensor causing the coils to fire. The reason you wait 10 minutes is b/c you are actually charging you cars battery from the drill battery because the drill battery isn't designed to provide the high current required to crank the engine. This will work as long as the drill battery is charged to a higher voltage than the discharged car battery. Once the two batteries voltages are the same no more charging takes place, leaving the drill battery attached will give slightly higher amps but if the car battery is really dead you risk melting the drill battery.

jeffmika (author)2014-11-22

He knew the battery is weak and ONE DAY wouldn't start the car....hmmmm.?...sounds like the battery isn't the only problem here...kinda sounds the owner needs a jump start?... adversity comes in a door we purposely leave open.....semi trucks use 24volt starters...4 -12 volt batteries..two SETS of two in series....smaller TOWN trucks use 12volts...2-12 volt run in parallel.... :-)

snoopindaweb (author)2014-11-21

cOOl. ~(:-})={> --- ]

MrSandman818 (author)2014-11-20

You can run higher voltages for a short time. At every big rig dealership I've worked at we have a battery jump box we use to start dead trucks. There's two options for voltage. You have 12v and 24v. If the truck batteries are completely dead we put it on 24 volts and hit the power button on the box just seconds before you go to crank the truck over. The second the truck fires up you have to let off. If you hold the battery box button for longer than 5-10 seconds it will start rolling smoke off the connection.

Big rigs use 24 volts not 12 volts anyways.

Some use 24 volts. Some components used 24volts and others like the lights use 12volts. All depends on application.

Actually they use 12volts. They run 2-4 batteries in series. 12volts with a crap ton of amps to aid with starting the large engines and to run accessories for the driver in the sleeper when parked. Military vehicles use 24volts. There's always the trade off between voltage and amperage. The more volts used means the less amps needed. All depends on application and the demand.

Two 12 volt batteries in series add up to 24 volts.

Good to know. I actually had another drill with a 24v battery. I did not want to risk it, so I went for 12v drill battery.

Ya no worries. That's the beauty of a forum. We're all here to help each other.

lumi3005 (author)2014-11-20

Well, if you would drive a Porsche, you wouldn't need a jump-start :-D

ShakeTheFuture (author)lumi30052014-11-20

If you are lazy or can't afford to change the battery in time, there will be always a possibility that you'll need to do a jump-start, no matter what you drive :)

I used to live (and work) in a hotel. It was never a problem to start a car as there was always somebody around to give me a push :)

lumi3005 (author)ShakeTheFuture2014-11-21

That's what I am talking about. Driving Porsche means you are not short on money and you can afford the annual car checkup where they maintain the battery as well :-)

buju357 (author)2014-11-20

My friend once used a 24 volt ARC welder to charge his cars dead battery. He set the welder to 60 amp ( the lowest) , put the welders terminals on the battery for 60 seconds , then disconnected them , and bingo , the car car started.

Luckily he knows all about electric current , volts , etc ... , but the jolt that the welder gave the battery was enough to start the car. I wouldn't keep the welder on the battery for more than 60 seconds , the battery WILL explode.

ShakeTheFuture (author)buju3572014-11-20

That's an interesting approach.

HeWolf (author)2014-11-20

When all else fails use cell phone battery to reschedule appointment. :)

ShakeTheFuture (author)HeWolf2014-11-20

Good one :)

MichaelAtOz (author)HeWolf2014-11-20

LOL, when reading, you get to 'cell phone battery' you go WFT, then punch line. Nicely done...

About This Instructable




Bio: Innovative Projects, Diy's, Life Hacks
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