How to Jump Start a Car





Introduction: 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.

Step 2: Connecting Step 1

Now to connect the cables.

First, connect one of the positive (red) of the jumper cables to the dead car battery (+ or red) There might be a plastic cap to pop off too.

Step 3: Connecting Step 2

Connect the positive (red) cable to the good battery. There might be a plastic cap on this one too.

Step 4: Connecting Step 3

Connect the negitive cable (black) to the negitive post (- or black) on the good battery.

Step 5: Connecting Step 4

Now connect the last negitive cable to a shiny part on the engine or directly connected to the engine by a big chunk of metal. A nut will work nicely as long as its not painted oily or really dirty. A spark is normal when connecting this last cable.

Step 6: Starting

Start the car with the good battery and let it run a few mins to charge the dead battery. Now before trying to start the dead car it is recommended to shut off the good car. But in my experience most of the time you need the extra juice of the alternator. So I myself almost allways leave the car running and I have not had any problems.
Anyways all thats left is to try and start the dead car. And once started disconect the cables th opposite way you put them on. The battery on the dead car will not have much of a charge so you should put a battery charger on it as soon as you can. I hope this has been some help and good luck.



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    36 Discussions

    car battery are an issue when it is about to replace a battery. Must concentrate on the quality of the battery, Click on car battery and get satisfied with the durability and quality.

    I found some other important tips on boosting the battery

    "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.

    2 replies

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

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

    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.

    14 replies

    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.

    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

    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 ;)

    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).

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

    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 ;)

    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

    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 ;)

    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

    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."

    wow th'ts 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

    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