1) Maintain Your Car's Battery.
Maybe the manufacturer says your battery is maintenance-free, but don't you believe it! Check your battery regularly to extend its life and avoid the hassle of being stranded with a dead battery. Here's some valuable pointers:
a) Begin with the simple: keeping your battery clean. A dirty case can actually cause current to drain. Wipe with a damp rag. Use a mild detergent if necessary;
b) Next, clean the battery posts or terminals. Loosen and remove the negative cable (black or minus sign) first, then the red positive cable. Use a brass wire battery brush dipped in a paste made from a few tablespoons of baking soda and a little water;
c) Inspect the battery case for damage, such as cracks or bulges -- signs that a battery needs to be replaced;
d) Reinstall the cables, positive first, and coat the terminals and clamps with a thin coating of grease to prevent new corrosion;
2) Some Batteries Need Water.
If your battery has vent caps, remove them to check the level of the electrolyte. It should rise 1/2 inch (13 mm) above the battery's top plates. If it doesn't, use distilled water to raise the level to 1/4 or 3/8 inch (6 or 10 mm) below the bottom of the vent cap. Don't use tap water, as it may contain minerals that can damage your battery. Mechanics should check your battery as a part of your regularly scheduled maintenance, but they often skip the procedure. Be sure to ask to have it done.
3) Be Kind To Your Battery.
If you inadvertently leave your lights on and drain your battery, take the following precautions to prevent damage to the battery and the starter when jump-starting your car:
a) Don't risk causing the battery to explode. With both cars off, connect a positive cable end to the positive battery terminal of the dead battery;
b) Connect the other positive cable end to the positive terminal of the source battery;
c) Connect a negative cable end to the negative terminal of the source battery;
d) Attach the remaining negative cable to unpainted metal on the car engine (as far from the dead battery as possible);
e) Wait a few minutes and try to start the disabled car. If it doesn't start, start the source car and then try starting the dead one again;
f) When the car starts, be careful to disconnect the cables in the reverse order;
g) If the car still doesn't start, don't keep trying to charge it or you are liable to damage the starter. Bring the battery to an automotive shop to see if it can be recharged;
h) Even if you're successful, ensure a full recharge by hooking up the battery to a charger overnight or by driving the car for 5 or 10 miles (8 to 16 km).