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How to use jumper cables and change your car battery
While we're talking about cars, you should also know what to do if your battery dies. Sometimes, you just need a jump to get home, and you can take care of it later. Sometimes, you just need a new battery. Either way, you'll want to try to jump it first.
Attention: Always follow these instructions in order to avoid electrocution. Also always read your vehicle's manual for the manufacturer's recommendation on jumping and changing batteries, as some cars do have special instructions.
- Jumper cables
- Car battery (purchase when necessary: Do not carry an extra with you)
- Baking soda
- Water (just carry a bottle in your trunk)
- Battery terminal cleaner (optional)
- Crescent wrench, adjustable wrench, vice pliers or socket wrench (find out in advance which works best on your car)
- Hammer (optional)
- Corrosion protection spray
- Safety goggles
- Old cooler
- Shop rags
- Baby wipes
- Duct tape
Instructions for jumping a car:
- Find a driver willing to allow you to use their vehicle as a jumping car. Park the vehicles close to each other so the jumper cables can easily reach each vehicle, but not touching each other. Turn both cars off and put them in park.
- Clamp the positive (red end) of the cables to the dead car's positive terminal (marked with "+") firmly.
- Do the same with the positive end of the booster car's battery.
- Now clamp the negative end of the jumper cable (black) to the negative end of the booster car's battery (marked with a "-").
- Clamp the last remaining negative end of jumper cable to a bare metal surface on the dead car (i.e., a bolt or screw) to provide grounding for the jump start.
- Ensure the cables themselves aren't touching any other parts of the engine.
- Start the booster car's engine and allow it to idle for a few minutes. Start the dead car's engine and, if it starts, allow it to idle for a few minutes. It's OK to try two or three times with a couple minutes between each attempt, but if it doesn't start a third time, it's dead.
- Disconnect the jumper cables in this order: Remove the negative/black from the formerly dead car, remove the negative/black from the booster car, remove the positive/red cable from the booster car, remove the positive/red cable from the formerly dead car.
- If the car doesn't start, you may need a new battery.
Instructions for replacing a car battery:
- Determine where your battery is located. In some vehicles, it's under a battery cover or even in the trunk or under the back seat. If you can't get to it, you may need to hire a pro.
- Turn off your car and remove the keys to ensure there will be no electric sparks.
- Set your tools out on the cooler lid (you can place the lid on the car as long as your car's engine isn't hot). Never set your tools on the car. It can cause dangerous sparks, and you may drop tools into the car, which can be hard to retrieve. Set the open cooler in the trunk of your car, leaving the trunk open.
- Clean the battery terminals if you haven't already. Use the terminal cleaner to brush any excess leakage.
- Inspect the battery for cracks where battery fluid can leak out. If you see any, cover them with duct tape so you'll remember where they are so you won't touch them later.
- Don your gloves and goggles to remove the old battery to protect you from any dangerous fluids leaking from cracks on the battery.
- Unscrew the nuts on the hold plate (if applicable) and remove (you may have to remove the cables first).
- Start by loosening the bolt that connects the negative terminal to the vehicle (again, righty-tighty, lefty-loosey) and slide the connector completely off the terminal.
- Then do the same for the connector attached to the positive cable.
- The nuts should be the same kind that attached the cables to the terminals.
- Set all the hardware you've removed somewhere safe (on the ground or on the cooler lid).
- Remove the battery by pulling it straight out by the handle. If the handle is corroded, hold it by the sides. The battery is going to be very heavy, so don't be afraid to set it down on the ground on occasion, but don't slide it along the ground, as it contains dangerous chemicals. Place the old battery inside the open cooler in your trunk to ensure no dangerous fluid gets into your car. (Do not use the cooler again for food.)
- After ensuring the terminals and cables are free of corrosion, apply the corrosion protection spray.
- Lift the new battery (which will be heavier) and situate it in the battery seat, leaving the colored caps in place to help you remember which side is positive and which is negative (red is positive, so make sure that's facing the red [positive] cable.
- Remove the red (positive) cap and use the terminal cleaner brush on it. This will score the post slightly and create a better grip when the cable is tightened around it. Spray it with corrosion spray. Fasten the cable back on the terminal and screw it on as tightly as you can.
- Do the same with the negative (black) terminal.
- Replace the hold plate and screw it on tightly (you may have to do this before attaching the cables). Don't skip this step. It will keep your battery in place as you hit bumps in the road.
- Try starting your car. It may take a couple of tries to get going, and you may have to enter your password to restart your car's onboard computer.
- Replace your tools and cover the battery in the cooler with the lid. Drive immediately back to the place where you purchased your battery to turn it in so it can be disposed of properly.
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