How to Rejuvenate a Car Battery

There are two different ways to rejuvenate a car battery. The most popular method is to charge the battery. The alternator in a car restores a battery during operation, but does not fully recharge the battery. Lead sulfates form from the sulfuric acid and lead plates inside a battery and can cause up to 75 percent of premature car battery failures. Desulfating a car battery helps reduce the crystalline sulfates that insulate the lead plates and increase the flow of the battery's current. Using both methods will prolong your battery's life.

Things You'll Need

• Safety glasses
• Battery terminal cleaner tool
• Wire brush
• Battery terminal protector spray
• 12-volt car battery desulfator
• Hand wrench set
• Battery charger

Instructions

1. Put on the safety glasses and remove the positive battery terminal clamp from the car battery using a hand wrench. Clean the clamp and terminal post of the battery using a battery terminal cleaner tool. Use a wire brush to scrub away any noticeable corrosion build-up on the terminal and clamp. Clean the post and clamp thoroughly, then reattach the clamp and tighten it. For side post batteries, disconnect the positive terminal, remove the protective cover (slide it off) and clean the flat, round terminal end with a wire brush.

2. Repeat Step 1 for the negative battery terminal post and clamp.

3. Spray anti-corrosion battery terminal protector spray onto each clamp and battery post. This will coat the posts and clamps and prevent recurring corrosion build-up.

4. Install a car battery desulfator (see Resources). Most desulfators can be easily installed by loosening the battery terminal clamps and inserting the appropriate clips (red clip for positive; black clip for negative) of the desulfator into the appropriate (positive and negative) clamps of the car battery. The desulfator can be attached to the battery, the battery tray, or a nearby bracket or brace in the engine compartment. Ensure that the wires connecting the desulfator to the battery do not come into contact with any moving engine components during operation. The desulfator can remain connected to the battery permanently or on an as-needed basis.

5. Charge the car battery with a battery charger. A car battery charger allows you to fully restore the amperage output of a car battery by converting AC electricity coming from an electrical outlet in your home (or shop) to DC, and controls the amount of electricity charging the battery to prevent over-charging or overheating of the battery.

6. Connect the red alligator clamp of the battery charger to the positive battery terminal first, with the battery charger unplugged and in the "off" position (if applicable).

7. Connect the black alligator clip of the battery charger to the negative battery terminal next.

8. Adjust the settings on the faceplate of the battery charger. Refer to the owner's manual of the charger for the proper charge. A slower, lower amperage battery charge is the best way to restore amperage to a car battery; it also helps to prevent over-charging or charging the battery too quickly. If there is a volt setting on the battery charger, set it to 12 volts. Set the battery type to "conventional" or "maintenance-free" (most car batteries nowadays are a sealed maintenance-free type). Set the amp setting to 2 amps for a slow "trickle charge." You can set the amperage higher if desired, but refer to the owner's manual of the battery charger to determine the amount of time per amp setting to charge the battery. Plug the charger into an outlet. Some chargers may power on once plugged in, but other models may need to be turned on with a power and/or timer switch.

9. Unplug the charger (or turn the power button off first, if applicable) and remove the charger in reverse order that you installed it.

References

• Revive Lead Acid Batteries

Resources

• Read this Article in Spanish
• Car Battery Desulfator