If you have ever unintentionally left your lights on after parking your car, you know how frustrating it is to come back to a vehicle with a weak or dead battery. Normally you would have to pop the bonnet and find someone with jump leads, or call for roadside assistance and wait 45 minutes or more for a mechanic to show up. There is a different alternative. You can get your battery charged by using your car's cigarette lighter and be on your way again without having to open your hood and without having to call for assistance.
Use an emergency car charger in much the same way as you would jump leads, except there is no need to open your hood. Park another car with a good battery next to the car that needs a charge. Plug one of the emergency charger's connectors into the cigarette lighter receptacle of the car with the dead battery. Plug the other end of the charger into the cigarette lighter of the good car. Start the engine of the car with the good battery and allow it to run, which will charge the weak battery in the other car.
Allow the car with the good battery to run until the LED lights on the charger indicate that the battery in the other car is charged. If your charger does not have indicator lights, allow the battery to charge for five to ten minutes if the battery is weak, or up to 25 or 30 minutes if the battery is dead .
Start the car that has just been charged. Remove the connectors from the cigarette lighters in both cars.
Alternatively, use a self charging battery jumper. Place the self charger on your centre console or on the passenger seat. Plug the charger's connector into your cigarette lighter receptacle. Turn the power switch on (if equipped) and allow the self charger to charge you car's battery for 10 minutes.
Start your car, but leave the self charger connected to your cigarette lighter while driving so it will recharge and be ready for the next emergency.
A third option is a one-time use emergency battery charger. Place the charger on your centre console or passenger seat. Plug the charger's connector into your cigarette lighter. Allow the charger to charge your battery for the predetermined time recommended by the charger's manufacturer. Start your car. Pull the connector from the cigarette lighter and dispose of the charger.