A gel, also known as a gel-cell, car battery is distinct in that its electrolytes contain a silica additive. This additive thickens the electrolytes, thus spill-proofing the battery and strengthening its resistance to corrosion. Because gel batteries are sealed, they can maintain their charge throughout periods of extended storage. However, you must take special care when recharging gel batteries; overcharging will dry out the thickened electrolytes. For this reason, you'll need a specific battery charger to recharge your car's gel battery.
Purchase a voltage-limited (float) charger if you don't already own one. This type of charger will limit the voltage to no greater than 14.1 volts and no fewer than 13.8 volts. A limited-voltage or float charger will monitor the charging voltage and turn off when the gel battery has reached a full charge. Never use a conventional battery charger on a gel battery.
Gain access to the gel battery. Depending on your vehicle, you must open a battery cover or remove guards that obscure the battery or any of its terminals.
Connect the float charger's negative clip to a bare bolt or exposed portion of the vehicle's frame or engine mount. Attach the float charger's positive clip to the gel-cell's positive terminal.
Turn on your voltage-limited battery charger, and plug it into a properly grounded electrical outlet. If the power cord cannot reach the outlet on its own, use a heavy-duty extension cord.
Monitor the gel battery as it charges. Though the limited-voltage charger should shut down automatically once it has achieved a full charge, check periodically whether the battery has become abnormally hot and ensure that the charger continues to function properly. If you notice any signs of overheating, unplug the charger immediately.
Disconnect the float charger once the gel battery has fully recharged. Unplug the float charger before disconnecting the float charger's positive clip, followed by the negative clip.
