How to Refurbish and Repair a Lead Acid Gel Battery

Open the battery’s vent caps to check the electrolyte level in each cell. Add distilled water to the bring the level up to the bottom of the fill hole if necessary. If your battery doesn’t have removable vent caps, it is maintenance-free and you should skip this step.

Use a trickle charger that matches your battery’s voltage output. Most cars use 12-volt batteries, but check the battery label or your vehicle’s owner’s manual to be sure.

Attach the charger’s clamps directly to the battery terminals if the charger has alligator-style clips. Clamp the charger’s red (positive) cable to the battery’s positive or “+” terminal and the black (negative) cable to the battery’s negative or “-” terminal.

Plug the AC adapter into a 110-volt receptacle and turn on the power switch. If your charger uses a solar panel to provide current, put it where it will be exposed to light for most of the day.

Leave the trickle charger connected while the battery is not in use to keep the battery’s charge topped up.

Take the proper safety precautions. A motorcycle battery contains sulfuric acid, which is extremely toxic. Wear goggles and gloves and work only in a well ventilated area. Keep open flames away from the battery and always allow the battery to cool to room temperature before working on it.

Remove the battery from the motorcycle. You’ll probably need to use a small crescent wrench to loosen the battery connectors. Remove the small plastic caps on the top of the battery (called cell caps) and drain the battery fluid completely.

Prepare a solution of 8 ounces of Epsom salts (magnesium sulfate) and one quart of distilled water (it’s much easier to dissolve the Epsom salts if you heat the water first to about 130-degrees Fahrenheit). Never use tap water in a battery because it contains chemicals that may damage the battery. Use a plastic funnel to fill each cell of the battery with the solution. Once each cell is filled, shake the battery gently to make sure the solution is well distributed inside the battery.

Place the battery on a six-volt trickle charger or a charger with a slow charge option. Do not use a regular charge rate as you would for an automobile battery. Motorcycle batteries are much smaller, and a powerful charging current will damage them and can produce flammable gases. Start with the battery charger off and hook the positive lead to the positive terminal and negative to negative. Leave the cell caps off during charging.

Turn the charger on low the battery to charge overnight or until the charger indicator says charging is complete. Then turn the charger off, remove the Leeds, and replace the cell caps. Reinstall the battery in the motorcycle, making sure the connectors are secure. The battery should now operate normally.

Remove the battery from the vehicle to charge it. Charging a fully discharged lead acid battery off of a car alternator can result in an overcharge and may damage the battery. Use a crescent wrench to loosen the battery cables. Always wear safety goggles and protective gloves when working with lead acid batteries, even the sealed type. The sulfuric acid in the battery is extremely corrosive.

Use a three-stage battery charger. This type of charger is designed for lead acid batteries and usually costs about $40-60 (as of 2009). Plug the charger into regular house current but leave it turned off. A sealed lead acid battery is equipped with a small tube called a vent tube to permit gases inside the battery to escape. Make sure it is free of obstructions. Connect the positive lead to the positive battery terminal and negative to negative.

A trickle charger is most effective when you are available to turn it off after the battery has charged. Overcharging your battery can cause permanent damage. If you are not available to monitor the charging process, or if your vehicle is in storage for a long period, a float charge that automatically turns itself off and on is your best option. However, if cost is a concern for you, trickle chargers are significantly less expensive.

Wear protective gloves and goggles before you rebuild the cell structure of your 12- volt battery. You need to access the cell reservoirs that contain highly toxic sulfuric acid that immediately burns on contact with skin.

Place your 12-volt lead-acid battery in a battery tray on a stable work surface. Remove the six battery cell caps on top of the battery. Either unscrew the caps using your fingers, or if the caps have slots, use a screwdriver. Each cell produces 2 volts and is linked in series to produce 12 volts. Put the caps to one side.

Check the fluid level inside the six cells. It’s likely you find the fluid level is below the minimum mark on the inside of the cells. This means the process of the electrons flowing from one lead plate to the other inside the cell has stopped. The fluid, called electrolyte, is sulfuric acid and enables a chemical reaction to take place between the positive and negative plates when the battery gets a flow of electricity from the car’s alternator or battery charger. If the fluid level drops below the minimum marker, the plates would be exposed, and they would corrode over time.

Rebuild the chemical cell structure by replacing the fluid. Use distilled water and top each cell up to the maximum marker inside the cell. It’s important that you don’t overfill the cell as during the charging process the cells get warm and the fluid expands. The distilled water will mix with any existing sulfuric acid in the cell and start to rebuild the chemical structure. However, for the process to begin the battery needs electrons to flow between the plates created by a small electric current from a battery charger.

Replace the cell caps using your fingers or a screwdriver. Don’t over-tighten.

Put the spring clamp on the end of the black battery charger cable onto the negative battery terminal. It’s clearly labeled “Neg,” “-” or may have a black plastic ring around the terminal pole. Put the spring clamp on the end of the red battery charger cable onto the other battery terminal. It’s clearly labeled “Pos,” “+” or may have a red plastic ring around the terminal pole.

Set your battery on the lowest setting possible; often called “trickle charge.” Rebuilding the chemical structure inside the cells takes time and it’s important the process is done slowly so the distilled water gets more acidic. As acidity increases so electron flow increases between the lead plates. Any corrosion on the plates caused by lack of electrolyte dissipates rebuilding the structure.

Plug in your battery charger and turn it on. Check the setting again to make certain it’s on the lowest possible. Leave the 12-volt lead-acid battery to charge slowly for 36 hours. During this time, the energy retention of the plates increases as chemical activity changes. You can check if the rebuilding process is working by touching the side of the battery after about 12 hours. You would find it’s getting warm indicating that the battery is taking a charge.

Turn off the battery charger after about 36 hours. Disconnect the battery cable clamps from the battery terminals. Place your hand on the side of the 12-volt lead-acid battery, and you find it’s fairly warm to the touch meaning the chemical cell structure is rebuilt, and your battery has retained a charge.

Dress in complete safety attire with goggles, rubber gloves and a rubber apron.

Work next to a continuous water source because a lot of water is required. Water helps dilute the acid of the battery; work in a well-ventilated area.

Take the terminal cables off the battery and remove them from the golf cart. Set the battery on a work bench.

Pry off the cell caps on the battery. Depending on the amount of corrosion, you may need a screwdriver to help you pry off the cell caps.

Turn the water source on and empty the contents of the battery into a container that is not made of metal. Make sure you have your safety gear on properly. Rinse out the battery cells with running water, pouring the water into the container.

Mix Epsom Salt and distilled water together in another container. The ratio of this mixture is 7 ounces of Epsom Salt to 1 quart distilled water. Use distilled water because it is free of minerals that cause corrosion in batteries. Stir the mixture, completely dissolving the Epsom Salt.

Pour the Epsom Salt into the battery cells, making sure each cell has the same amount of liquid.

Hook a three-phase charger to the golf cart battery. Leave the rebuilt battery charging overnight.

Take the rebuilt battery and put it back into the golf cart, reconnecting the battery terminals.

Start the golf cart and use for one week. At the end of one week reattach the golf cart battery to the three-phase battery charger and leave until a complete charge is accepted.

Remove the six plastic cell caps from the top of the battery. Use a screwdriver, or twist them off using your fingers.

Check the plates for sulfation. Look inside each individual cell. If the plates are completely covered in sulfur deposits, so much that you can’t see the plates, then there’s little you can do and a replacement battery needs to be purchased. However, if there’s only partial sulfur deposits and smallish crystals and parts of the plates are visible, then it’s certainly worth attempting a repair.

Pour distilled water into each cell carefully. Fill the cells up to the maximum marker that’s on the internal wall of each cell. Don’t overfill. Leave the battery for five minutes and then check the fluid level again, since you will find they need topping up. Leave off the cell covers for the moment.

Connect your battery charger to the battery terminals. The red clamp connects to the “+” terminal and the black clamp connects to the “-” terminal.

Select the lowest charge setting you can on your battery charger; it’s probably called “trickle charge.” It’s imperative you charge your battery slowly and for a long time to successfully repair it. For the sulfation to disperse, the distilled water you poured in the cells has to change into electrolyte, which is actually sulfuric acid. Because your battery had boiled dry, there was no fluid in the cells so the cells currently contain pure distilled water.

Turn on your battery charger and leave it to charge your battery for 12 hours. After 12 hours, take a look in the cells and feel the side of the battery, but don’t turn off the charger. The battery casing is getting warm and small bubbles are beginning to rise in each cell, if the repair process is working. If the battery casing is completely cool and no bubbles are rising, there’s little point in continuing as your battery isn’t taking a charge. You need to get a replacement.

Let the battery charge continuously for an additional 12 to 18 hours. This may seem like a long time, but it’s necessary to complete the repair. Now that you have seen bubbles rising, you know the repair is likely to work.

Turn off the charger. Remove the clamps from the battery terminals. Have a quick look in the cells — bubbles are rising rapidly. Most, if not all, of the sulfur deposits have dispersed. The side of the battery is also fairly warm, so you can be confident that your battery is repaired.

Replace the plastic cells caps. Screw then on using your fingers and then tighten them using a screwdriver, if appropriate.

Wear safety glasses. Protect your eyes from possible diluted sulfuric acid solution that can spark in reaction to the battery’s flammable hydrogen gas.

Place the battery charger on a concrete, flat surface away from flammable materials and wood. Use the charger in a garage or basement where it is away from household furnishings.

Place the volt setting of the battery charger on 12 volts and choose a low amp setting that will charge the battery slowly. Slowly charging the car battery will desulfate the crystallization of lead sulphates, providing a higher amperage output return.

Select the correct battery-type setting on the charger if applicable. Most modern car batteries use a conventional/low-maintenance battery. Use a compatible AWG gauge extension cord if necessary to reach the garage electrical outlet.

Apply the red positive alligator clip to the positive terminal end of the battery first. Place the black negative alligator clip onto the non-painted metal bracket. Activate the charger. Allow the battery to charge for six to eight hours. Never charge the battery over 8 hours (unless directed by battery-charger manual), as it can damage the internal components.

Test the battery’s voltage with a voltmeter and set its dials on the 0-50 V range. Disconnect the battery charger from the battery. Connect the voltmeter’s positive red lead to the battery’s positive terminal. Connect the black lead to the negative terminal. Check the voltage level; if the battery has a range of 12.6 to 12.8, the battery is charged. Keep charging the battery if it has a voltage under10 V.

Do a visual inspection of the battery. If there is any damage to the battery case or terminals, the battery should be replaced. Check the electrolyte level and make sure that the battery plates are covered.

Charge the battery fully before testing. Remove any surface charge to the battery by putting it to use in its application for a few minutes.

Have a copy of the manufacturer’s specifications for the battery nearby, as you will need to refer to them as you test the battery.

Take a hydrometer reading of all the cells in the battery. This is as simple as squeezing the bulb and releasing it so that it sucks up some electrolyte, and then reading the specific gravity measurement. Refer to the spec sheet for the minimum acceptable reading and difference of specific gravity between cells.

Take a voltage reading with the voltmeter and compare it to the manufacturer specs for a fully charged battery.

Follow the instructions for the digital load tester, and test the battery while it is being placed under a load. This type of tester will not necessarily measure the battery capacity, but it will indicate whether or not the battery has an interior defect. A battery that fails any of the tests with these methods will need to be replaced.

Turn the ignition key to the “Off” position. Locate the battery. Depending on the make and model of your scooter, you may find the battery under the seat or under a panel on the floorboard.

Plug the battery charger into an electrical outlet. Connect the battery charger’s red wire to the positive (+) battery terminal. Connect the black lead wire to the negative (-) terminal. If you connect the charger to the battery incorrectly, the scooter will not receive a charge.

Examine two indicator lights on the charger. A green indicator shows the battery charging; a solid red light shows the charger receiving power. A dim or flashing red light indicates an disruption in power. Press the “Reset” button to restore power to the charger.

Replace a battery that does not hold a charge. After one year of use, a battery may become defective, warns Pride Mobility.

Extreme heat in the summer can also have an adverse effect on the car battery. If the battery has been previously overcharged, extreme heat can increase the problems caused by overcharging, and exacerbate any other problems with the battery. This problem can be hard to avoid if you live in a warm climate. The only real way to ensure safety against this problem is to avoid overcharge in the first place.

Wear a pair of lightweight rubber gloves to protect your hands before attempting to recondition your battery. The fluid in the lead-acid battery cells burns if it gets on your skin.

Remove the caps on the top of the lead-acid battery. If the caps have slots in them, use a fairly large flat-head screwdriver to unscrew them, and then lift off the caps, using your fingers. Many cell caps simply screw in place, so you can remove them in this manner.

Check the fluid level in the cells. If the fluid level is below the minimum marker on the wall of the cell, it means the lead plates may be exposed, and sulfation may have occurred.

Use distilled water, not tap water, and top up all the cells to the maximum marker. Don’t go past the maximum marker, because the fluid expands while the lead-acid battery charges.

Leave the caps off the battery, and attach the two clamps on the ends of the red and black battery cables of the battery charger to the “+” and “-” terminal poles respectively on your lead-acid battery. Squeeze the clamp handles to open the jaws of the clamps, and then place the clamps over the terminal poles and release the pressure so the jaws of the clamps close securely.

Plug your charger into the power supply. Select a slow charge; a fast charge won’t satisfactorily recondition your battery cells.

Turn on your battery charger. To make sure it’s charging, check to see if the charging light is on, or check the charge display panel, if there is one.

Allow your battery to charge slowly for at least 24 hours; 36 hours are better, if you have the time. During this time the cell will start to recondition and turn the distilled water into sulfuric acid. The acid will remove the sulfation from the lead plates, and the electrons will start to flow from one plate to the other and take a charge.

Turn off your battery charger after 24 hours to 36 hours. Remove the plug from the power supply, and remove the clamps from the terminal poles on the lead-acid battery.

Replace the caps. Screw them in place using your fingers and then tighten them with a screwdriver, if they have slotted tops.

Remove the plastic covers from the top of the battery cells. There are either three or six covers, depending on whether your battery is a 6-volt or 12-volt battery respectively. Unscrew the knurled covers using your fingers. If the covers have screwdriver slots, then place a screwdriver into the slots and unscrew them.

Look inside the battery cells. You may need to use a flashlight to see. Look for the two markers on the walls in each battery cell. The mark nearest the top indicates the maximum fluid level, while the lower mark is the minimum. Sulfation occurs after the fluid drops below the minimum level. You can see sulfation on the plates, which looks similar to corrosion on metal, but is yellowish in color due to the sulfuric acid contained in the cells.

Trickle distilled water carefully into each cell. Fill the cells up to the maximum marker, but not above. You need to allow space for the fluid to expand, which takes place when a battery charges. Don’t replace the covers on the battery cells.

Place the clamp on the end of the red positive battery cable from the battery charger onto the positive battery terminal. It’s usually labeled “+”, or “Pos.” Place the clamp on the end of the black battery cable onto the negative battery terminal labeled “-” or “Neg.”

Set your battery charger to the lowest voltage charge setting. It may be called “trickle charge.” Don’t select a fast or boost charge as high charge settings will not properly remove sulfation from the lead plates.

Plug your charger into the power supply. Turn on your charger. Check that you have an illuminated light, which confirms that the battery is charging. If it has a meter, check that it’s registering a low charge.

Leave your battery to slow charge for 36 hours. As the battery charges, the distilled water you put into the cells will change into sulfuric acid. The acid will gradually remove the sulfation on the lead plates.

Check the battery after 12 hours. Look into the cells. You should see small bubbles rising, which confirm that the cells are charging. If you put your hand on the wall of the battery, you will find that it’s warm. If one or more cells are not producing small bubbles, it’s possible the cell is damaged beyond repair; but wait until the end of the charging time.