[Poppy]

Using a digital voltmeter, simply check across the battery terminals.
You should get 12.66 volts.
Next turn your headlights on for ten seconds and check again.
This dissapates any "surface charge"
It should still be in good shape.

Courtesy Mark v
Battery Charge Table
12.6V or higher: 100% charge
12.4V - 12.6V: 75-100%
12.2V - 12.4V: 50-75%
12.0V - 12.2V: 25-50%
11.7V - 12.0V: 0-25%
11.7V or less: 0% (and probably not capable of being recharged)

If it needs to be charged, charge it up overnight, and check it in the morning, as above.

IF it is dead in the morning you need to rule out if there is something draining the battery or if the battery just doesn't hold a charge anymore, and needs to be replaced. To test the battery, disconnect it, charge it up and let it sit overnight, then recheck the voltage. It should stay at the 12.66 overnight.

See How to check for a parasitic drain if needed.

 

[theoldwizard1]

Best thing you can do for your battery is keep it clean. A little baking soda dissolved in a small container of water and an old paint brush (or parts cleaning brush) will do wonders. Rinse with clean water.

If you are real lazy, just spray it down with the garden hose !

A bit of silicone dielectric grease on the terminals is a good idea also !

 

[sniper 7822]

If you are real lazy,[/B] just spray it down with the garden hose !

u can just use coco-cola soda thats work i seen in father in-law use many time's ...lol.. but i dose works

 

[Jonzo77]

or if you have a fairmont with the 200 inline 6 it WILL start as low as 11.50V. it's worked tons of times...