How to jump start a car

In this instructable I will show you the basics of jump starting a car.

Step 1 Getting Ready

First off make sure you have everthing.
1. Jumper cables
2. A car with a good battery
3. A car with a dead battery

Park the good car so that the batteries are close enough to connect each other with the jumper cables.(duh)
Then pop the hoods and find the batteries.

Comments

[ffsman]

I found some other important tips on boosting the battery http://howtohacklife101.blogspot.com/2011/05/how-to-jump-start-car.html

[xray88]

"Now before trying to start the dead car it is recommended to shut off the good car. The sudden power strain can kill the diodes in the alternator." There is no danger to the alternator diodes of the donor car being in danger of a "sudden power strain". There is a voltage drop through the cables. The voltage of a running car is higher than battery voltage. So if you leave the engine running, you are starting at about 1.2-2V higher, which will help overcome the voltage drop in the cables. If you shut the car off, you are significantly reducing the chances of the engine with the low battery starting. Ruining alternators from properly jump starting cars is the stuff of urban legends.

[tbonecb]

I talked to some ppl about this and your right. Thank you for letting me know

[harley_rly]

we actually rev the motor a little whenever the car with the dead battery still has a hard time starting

[lasersage]

might be worth mentioning why you do this - to stop the spark igniting explosive gas fumes coming from the dead battery.

[joejoerowley]

You forgot to mention to take of any watches. You can be electrocuted.

[xray88]

"You can be electrocuted " No, you can't. There are other safety reasons for taking off jewelry while working on automobiles, but electrocution isn't one of them. No one has been electrocuted from the battery or charging system from a car before, as the amperage is very low. The worst you'll get is a shock that will wake you up a bit if you touch part of the high tension circuitry, but you wouldn't be doing that while jump starting a car anyway.

[lasersage]

I agree that it is unlikely you'll be electrocuted by the low voltage circuitry (12 or 6V) but this is due to the low voltage, not the current. Low voltage can't penetrate the skin and get into the conductive blood vessels. You say that "the amperage is very low", that is not true. The current is actually huge when starting a car, that's why you have such beefy wires going to your starter motor. Sorry to nitpick, as your other stuff looks sound.

[CameronSS]

Heh...you could on my car...Ford Courier powered by twenty 6V golf cart batteries...touch your watch on that and it'll vaporize the watch and burn your hand off...

[Myself]

But that's a burn, not electrocution.

[xray88]

We're talking about standard autos here that would be getting or giving a jump start, not a car with twenty batteries. But regarding your post, burning your hand is not electrocution. As I stated, there are safety reasons for not wearing jewelry while working on automobiles, but electrocution is not one of them.

[CameronSS]

Oh, picky, picky...hey, EVs WERE the standard in the early 1900s, before Big Oil killed them.

[xray88]

Yes, how picky of me to point out the difference between burning yourself from 20 batteries and being killed from an electric shock from a modern automobile.

[sedition]

Might want to add that after jumping, the dead car should be driven for about 20 minutes to recharge the battery fully, otherwise you end up with a dead car again.

[xray88]

20 minutes will not be long enough to fully charge a battery that was weak enough where it couldn't start the car. Will it be enough to start it again later? Possibly. But after a jump start, the battery should be fully charged with a battery charger to ensure a long battery life. An alternator is a trickle charger and is not a substitute for a battery charger. By not fully charging your battery, your battery will constantly be in a semi-charged state and will not live out a normal life expectancy.

[microman171]

car battery chargers are mostly always trickle chargers... It means you need to take the battery out (I might be wrong (Im 14)) The charge it then put it bake in when you wanna go out some where

[karcinagin]

You don't have to take it out

[trebuchet03]

You can connect a trickle charger to the batter while it's still in the car ;) Just don't start the car with it connected.... Perhaps it was me using a very old charger, but it no longer worked after that :p Some of the more hard core mileage guys will do just that... I know of some people that run without an alternator for short trips, and recharge their battery on a solar collector ;)

[Derin]

hmmmm,is his name starting with Tim?

[Punkguyta]

So now, why the hell would you run your vehicle without an alternator??? (This is assuming it had a perfectly fine one in the first place).

[trebuchet03]

Takes load off the engine which means better mpg numbers...

Here's someone that quantitatively tested

[bikerbob2005]

can get a vacuum actuated switch install it on the "field" wire so when no vac no power to alternator, no load on motor .can find such on an 86 hyunda excel lot of them in salvage yard. i see an instructable on it i better get busy

[Punkguyta]

Good idea at first, but only good for people that have luck finding car batteries that "fell off the back of the trans. truck".

[trebuchet03]

He talks about battery life on his site :p I think he's got a source of batteries that's either free or near to free. I'm fairly certain that's what he's using for a "low" cost EV he's building ;)

[Punkguyta]

He never said on the site that his batteries were coming to him free, rather that he said this was practical for someone in the said situation. And wouldn't "EV" imply that it's an all electric car? By removing the alternator from the picture, it's actually less of and EV and more of just gasoline engine. It's a good idea in theory, but until we get batteries developed that have infinite charge cycles, we're all doomed as far as cheaper driving. -P

[trebuchet03]

I never said this was done on an EV, I said he's got a free or close to free source for batteries. Please make sure to read what I say at face value.

Perhaps he didn't say it on his site (and I never said it you'd find that information there) - but he's active on other websites ;)

As he said But there's a big caveat: the immediate fuel savings may not make financial sense in the long run when you consider the effect on battery life. It's "may not" as the only way to find out is to test ;)

[Punkguyta]

I'm getting a chevy caviler soon, would be an interesting vehicle to try it on, but it's already good on gas so why bother with a few more dollars saving? Oh that and making a belt for the entire engine system would just be wonderful but another day please :P -P

[trebuchet03]

Considering our car's getting 30mpg, even 40mpg as great, is laughable overseas ;) The average fuel consumption is Europe is 43mpg - and 50 in Japan... In the US, it's right around 27. Accepting "Good Enough" has always been shy of "satisfactory."

[harley_rly]

wow th'ts great...my moms car only gets 24 MPG, my truck gets like 15-20MPG, and my brothers car(a 289 V8 with a Four-Barrel Carb.) like gets 10-15 MPG lol

[knarx]

Woohoo, here is mine, I just saw yours in the realted instructables.
http://www.instructables.com/id/Jump-a-Dead-Car-Battery/

[lemonie]

Now do how to bump-start a car. L

[hack124x768]

Only works for a manual, but flip on the ignition, put in in first or second (depends on the car), push in the clutch, get it going around 10 miles an hour, give it a little gas. pop off the clutch, give it more gas. Have fun.

[hay_jumper]

Exactly. But where are your photos?

[DonQuijote]

How about an instructable that'll show us how to start a car with a low battery, WITHOUT using another car....perhaps it's a good idea for my first instructable to come.....i'd need some pictures though

[trebuchet03]

I also have the running car bring the rpm's up a little to put the alternator closer to it's peak performance before starting the dead battery. Especially when you're starting a car that requires extra cranking amps.