How to care for your car battery？

Step 2: Check the level of the electrolyte

To test the electrolyte in each cell, squeeze the ball on the hydrometer and draw the solution into the tester. Hold the test level, record the reading and squirt the solution back into the cell.

Test the electrolyte in each cell. Squeeze the ball and draw the solution into the tester. Carefully hold the tester level and write down the reading. Squirt the solution back into the same cell. The testers are calibrated assuming a battery is at 80 degrees F. Add .04 to each reading for every 10 degrees above 80 and subtract .04 for every 10 degrees below. If you get a cell reading that differs from the others by .05 or more, replace the battery. A fully charged battery should have a reading of 1.265 or higher. If all the readings show fair or low (1.200 is low) but are consistent, recharge the battery. 

Step 4: To drop in the new battery first remove the cables

Disconnect the negative cable first and then the positive

Remove your battery hold-down clamp. Disconnect the negative cable first, then the positive. Note: Always replace the battery with one that has a higher rating than the original.

Step 5: Replace the battery

Use the heavy-duty strap to carefully lift out the old battery

Step 6: Reinstall the clamp and cables

Connect the hold-down clamp before connecting the cable to the terminals

Carefully lift the new battery into place. Connect the hold-down clamp, then connect the cable to the positive terminal first and the negative last (for negative ground systems). Smear a little petroleum jelly onto the terminal before fastening the cable clamps to the posts. The grease will help slow corrosion. Most batteries are at least 75 percent charged when you buy them and should be ready for you to start your car and drive. Check with your supplier to see if your new battery needs charging before you use it.

Battery Storage: Use a Battery Maintainer

You've emptied the gas, sealed the exhaust and prepared the engine for seasonal storage. But before you throw the tarp over your boat or roadster for the long winter sleep, think about how you're going to care for the battery.

Batteries lose their charge when they sit idle, and when that happens, you could wind up with a worthless battery in the spring. To keep batteries healthy, they should be charged every six weeks. But leaving a standard battery charger connected for the whole season isn't a good idea—that will overcharge the battery and shorten its life. Instead, invest in a “battery maintainer.”

Battery maintainers are designed to be left on for the entire off-season. They monitor battery voltage and automatically adjust the charge to avoid under- and overcharging.

Battery charger/maintainers and quick-release terminals are available at most auto parts stores or online.

Telltale Signs of a Low or Failing Battery

• Your headlights look dim at idle and then brighten when you rev the engine.
• The starter turns slowly, barely starting the car. But you may have alternator wiring problems that prevent the battery from fully charging. If that's the case, schedule a service appointment. Check your fan belt. If it's loose, frayed, cracked or glazed, have it serviced or replaced.

A low battery can also be caused by:

• Frequent short trips.
• Too many accessories left on or added.
• Look for a purchase date chart on the battery (it may be handwritten). The battery case will also have a decal stating its expected life, such as 60 or 84 months. If it's near the end of this expected service life, replace it.