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How To Charge Car Dead Battery

Being stranded on the side of the road with a broken down car is something we all try to avoid. We service our vehicles regularly, maintain the fluid levels, fill the tires, and make sure the car is running at peak performance. Sometimes even the best maintained vehicles and even new cars can break down with one of the most common issues being a dead battery or bad connection (other than it being out of gas).


The first thing we need to do is figure out if the battery is the problem or if it’s something else causing the car not to start. Before you attempt to jump start the car, you need to determine if the battery is dead, low, has bad cable connections, or is actually functioning properly.

If you turn the ignition and hear the engine cranking or trying to turn over, you don’t have a dead battery on your hands, so jump starting the battery won’t solve your problem. If it is dead, nothing will happen when you turn the ignition.

If nothing happens when the ignition is turned, open your hood and take a look at the battery. Check the cables to ensure they are secure and not covered with corrosion or other obstructions. If they are loose or corroded, clean them off and secure them tightly. Then try to start the car.

Note: When disconnecting and connecting the battery cables, disconnect the NEGATIVE CABLE first and reconnect the NEGATIVE CABLE last.

If it still won’t start, you may have a dead battery that needs charged.


It’s always a good idea to carry a good set of jumper cables with you at all times as you never know when your car or someone else’s will have a dead battery.

1. Make sure BOTH CARS are turned off.

2. Connect the RED (POSITIVE) JUMPER CABLE to the positive terminal of the dead battery.

3. Connect the RED (POSITIVE) JUMPER CABLE to the positive terminal of the good battery.

4. Connect the BLACK (NEGATIVE) JUMPER CABLE to the negative terminal of the good battery.

5. Connect the BLACK (NEGATIVE) JUMPER CABLE to a CLEAN, UNPAINTED METAL SURFACE under the disabled vehicle’s hood.

Note: DO NOT hook the negative cable to the negative terminal of the dead battery. This could cause sparks and a possibly explosion.

6. Start the vehicle that’s not disabled and run it for 2 to 3 minutes allowing the battery of the disabled car to charge.

7. Try starting the disabled vehicle. If it doesn’t start, charge it for a little longer.

8. If the disabled vehicle does start, let it run for at least 30 minutes before turning it off to give the battery enough time to recharge itself.

9. Disconnect the jumper cables in reverse order (1. negative on dead battery, 2. negative on good battery, 3. positive on good battery, 4. positive on dead battery).


How To Charge Car Dead Battery



  • A dead battery is one that will not hold a charge, and in some cases, they are unable to take a charge.
  • It can take several days to a couple weeks to revive a dead battery, depending on how bad the battery is, the size, and how often you cycle(charge and discharge) the battery with BLS attached.
  • For a 12 volt battery, you will need the BLS-12/24-B and a good automotive battery charger, preferably with a rating of 6 to 10 amps. For batteries that cannot take a charge, it is best to use an old fashioned battery charger, not one of the newer high tech Smart Battery Chargers. The newer smart battery chargers will not turn on if the voltage of the battery is too low. This does not mean that the battery is completely dead, just that the charger will not turn on. If you do not have a manual charger available, you can jump start the bad battery(just like jump-starting your car battery) to get the battery voltage high enough for the smart charger to turn on (contact us for more information on this procedure).
  • The key to this procedure is to cycle (charge and discharge) the battery with the BLS attached. The BLS gradually dissolves the sulfate crystals with every cycle. To Battery Life Saver works from the power of the battery. You can either let the BLS discharge your battery or add some type of load(i.e. a light) to help discharge the battery.
  • Step 1: Connect both the BLS and the charger to the battery, paying attention to the polarity.
  • Step 2: Charge the battery with the BLS attached until the voltage is at least 12 volts or completely charged.
  • Step 3: Leave the Battery Life Saver connected to the battery without the battery charger for a
    period of time(if it is a single 12 volt battery, 20 hours should be enough time to discharge with the BLS). DO NOT LET THE VOLTAGE GO BELOW 10.5 VOLTS. It is best to stay above 12.2 volts on a 12 volt battery.
  • Step 4: When the battery voltage is between 12.2 and 12.5 repeat step
    2 and 3.
  • Work back and forth between 2 and 3 until the battery comes back up to operational condition. If you cycle(charge and discharge) the battery every day with the BLS connected, the battery should come back sometime between 3 days and 2 weeks.


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