How to charge a car battery?

1. To jump-start your car, you will need two things: jumper cables and a car whose battery is not dead. 
2. Find someone with a car whose battery is not dead. Ask if they have jumper cables. If they don’t, find someone with jumper cables.  
3. Park a functional car with the booster battery next to the car with the dead battery, making sure that the two vehicles are NOT in contact.
4. Ensure the booster battery is 12-volt and has its negative terminal grounded.
5. Turn off all unnecessary electrical loads.
6. Open the engine hood and remove the service cover on the front passenger seat side in the engine compartment. 
   *Accessibility of your battery depends on the make and model of your car. Some may even be in the boot or under the seats. 
7. Remove the fuse box cover. Open the positive terminal cap inside the engine room fuse box and the negative terminal cap close to the vehicle body. 
8. Connect one end of a jumper cable (red, positive clamp) to the positive end of the discharged battery.
9. Connect the other end (red, positive clamp) to the positive end of the booster battery.
10. Connect one end of the other jumper cable (black, negative clamp) to the negative end of the booster battery, then the other end (partnering black, negative clamp) to a solid, stationary, metallic point away from the battery.
11. Start the engine on the functional car to begin charging the dead car battery through the jumper cables, and let it do so for a few seconds.
12. Once the dead car comes alive, disconnect the jumper cables in the reverse order (first the black, negative clamps followed by the red, positive clamps) while making sure that the clamps do not touch each other.
13. Go on a quick drive or let it idle for at least 20 minutes to build up the charge.

Follow the basic instructions below to charge your battery:

1. Ensure the battery charger is off.
2. Connect positive and negative cables on the charger to the respective ends on the battery.
3. Keeping the charger at its slowest charge rate, turn it on and set the timer. Depending on the battery voltage and its cold cranking amps (CCA), it should take about 6-12 hours to fully charge.
4. Once done, turn off the battery charger main switch.
5. Disconnect the negative first then the positive clamps from the respective battery terminals.