How do I recharge a dead battery?

Question

My truck's battery went dead overnight due to the keys were left in it with the radio on. Can you walk me through the process start to finish? Which cable to which terminal? Attach to which vehicle first? Should the other car be running before attaching cables or not?

Answer 1

First assumption,you probably need a 12volt battery charger, charging a really dead battery from a car can at times cause the other cars alternator too much strain - so borrow a charger and cahrger it over night at trickle charge

If it is a maintenance free lead acid battery, you will have to buy a battery soon - running down a battery really sucks the life out of a conventional battery

If you are wanting to jump your car- follow these steps

1. Park the other truck, (use a truck to jump a truck), in a comfortable manner so the cables can easily access each other car's battery -set the parking brakes firmly

2. Find and Use jumper cables that are heavy duty, and free of rust and corrosion... make sure the wires are snug within the compression lugs or screw terminals on the clamps

3. Open the hood of the ttruck, Check the ground (-) the cable will be black without any markings and most likely have a little white rust on it - make sure this is clean - even remove the cable from the battery terminal and scrub it with baking soda and a wire brush if it is excessive. then reistall cable and tighten to snug - do not tighten excessively

4. Now you are ready to jump-start. open the hood of the other truck. Before starting any engines make sure you don't drape cables or other items in areas of moving parts, especially the belts that turn your a/c, alternator, water pump...

Start the engine of the other vehicle. If you are in a cold climate let it warm up (i know it is summer)

5. exit the vehicle and grab the cables
start with the black cable and clamp it to bare metal of the running truck frame or engine (recommended by most car manufacturers) if this is too difficult - clamp it to the negtive (-) terminal of running car first - than connect the other side of black to the dead battery.

6. Make sure that both sides of the red cable clamps are not touching any part of the other vehicle chasis or metal parts - use another person if you have to - or clamp the red firmly to rubbe hose - do not touch metal or this will short out the batterys - THe Negative is the same as the truck chasis - as these are bonded together.

Next clamp the red on the side of the dead vehicle to the positive terminal(+) then connect the other side at the running vehicle - you should see a small, cool spark - if the spark appears to be welding the clamp to the battery or whatever you are touching you are grounding the battery and getting full load current - therefore do not do this.

Then let the running vehicle charge the other battery for about 15 minutes.

Then try starting the dead car - if it fails - let it charge even longer - if it takes more than one hour - use a real battery charger and charge over night

If the truck starts, or you want to remove the cables - reverse the order starting by removing the positive (+) on the running vehicle then the dead cars(+) than remove the ground on whateve is convenient

Also if you charge your battery overnight, dont close the hood on the charging cables - they might short out the leads -check the battery water level if you have a non-maintenance free battery.

And good luck

edit:::: Also listen to peanut brains, he has a valid point, most batteries act as a buffer that smooth out the current and voltage, some computers in cars are sensitive to stray voltages and currents and replacing them is not on the cheap

Answer 2

First connect the positive terminals (+) of the batteries using the same color connectors (usually red or green) on the jumper cables. You can start with the dead battery and then the working battery.

Then connect one of the opposite (usually black) connectors to the WORKING battery's negative terminal (-).

DO NOT connect the remaining connector to the dead battery's negative terminal! It needs to be grounded by connecting it to something metal (unpainted metal, like a bolt or metal support) in the engine compartment. Not grounding the flow of electricity can be very dangerous.

Run the car with the working battery for about five minutes. Try to start the vehicle with the dead battery. If it doesn't start the first time, try a minute or two later. If it doesn't start after ten minutes, you probably need a new battery.

Now, to take the jumpers off, you need to work in reverse order. First remove the grounded clamp from the metal.
Remove the clamp on the negative of the working battery.
Remove the clamp from the working battery's positive terminal.
Remove the clamp from the formerly dead battery's positive terminal.

Let your vehicle run or drive around for a bit to fully charge the battery.

Answer 3

Start with both vehicles off.

Attach positive and negative cables to the respective battery posts of the dead car. WITHOUT letting the other end of the cables touch, attach the other positive cable end to the positive terminal of the dead battery. Then attach the other negative cable end either to the engine block of the dead car or the negative battery terminal of the dead battery.

Start the "good" car and let it run for a few minutes. Try to start the dead one (it may help to have someone rev the good car while you crank the dead one).

Answer 4

To jump a car battery:

First you need jumper cables, and an automobile with a working battery. With both cars off, connect positive to positive, and negative to negative. If you cross it, connecting positive to negative, you will short out all the electronics in your car.

Once they are attached, have the person with the working battery start their automobile. With it running, start the one with the dead battery. Rev the engine a few times so that the battery gets charged up well. Then turn the automobiles off and disconnect the jumper cables, you're all set.

Detailed instructions for jumping the battery should also be found in the owner's manual of your car, usually found in the glovebox. You should consult it before doing this just in case there are any abnormalities in the way your car is designed.

Answer 5

raise the hood in both cars
get the cables put the red clamp to the +terminal on the truck
put the black clamp on the - terminal
do like wise on the other car + to + - to - have the out her car running try not to make it spark and don't smoke around the batteries let the car run foe a short while then try and start the truck if it doesn't start let IT charge a while longer
once the truck is running take the cables off + first on both car then the - let truck run for a while to charge the batt. back up hope this helps
happy day
old geezer

Answer 6

the best thing to do is get a battery charger then put the red clamp on the positive terminal or post and the black clamp one the negative post then plug in the charger let let it charge for a couple of hours then it should be OK after the battery is charged then un plug the charger if you don't have a charger then you can get some one to jump start your engine this is done buy connecting jumper cables from one car battery to another put the cables on just like if you were using a charger but you don't have to let it charge after you put the cables on then start your car after it starts disconnect the cables and you should be ready to go [but don't get the cable clamps on the wrong post if you do you will blow your battery and the alternator] good luck

Answer 7

You can have the other car running

BUT it is not good to boost another vehicle with another vehicle
You take the chance of damaging the computer

But if you insist

Hook red booster cables to positive on the battery
Hook black Booster cables to negative on the battery

Start ASAP to avoid damage to the computer

Unhook the cables after starting and let the vehicles own charging system charge the battery

Answer 8

make sure you attach the positive to the positive and negative to the negative otherwise you will have some big problems
its good to attach the jumper cables to the dead one first but it really doesnt matter
and leave them connected for a little while and let the other vehicle running, after about 5-10 minutes just start your truck but don't turn it off right away the battery needs atleast half an hour to recharge

Answer 9

Best to turn the car off first. Hook black to black red to red. Then start the car with a good battery let it run for a minute to give your battery a small charge then start your truck. Be careful no to touch the jumper cables together when hooked up and make sure you do not touch the red one to the car at any point this can short out one or both cars. Its easy just use caution. Hook up to good car first hook up red, positive cable, first.

Answer 10

I hook them up when the car is running. Positive to positive, negative to negative. Some recommend you hook the negative from the good battery to a ground point on the dead car besides the battery. I hook up the running side first, then the ones on the dead one. You may want to leave them hooked up for a little bit after it starts. I do, because they say you can burn up your alternator if your battery's too far drained. I figure two alternators working on it will give it enough charge after five minutes to keep it from burning out.