Lead-acid gel batteries are considered safer than regular fluid-filled lead-acid batteries. Each battery cell contains a thick gel, if the battery gets dropped or damaged and the case splits open, the gel remains in place, whereas a fluid-filled battery would leak dangerous sulfuric acid. Lead-acid gel batteries are sealed units, you can't access the cells and replenish the electrolyte. It also means they need to be charged and discharged differently from a regular lead-acid battery. If you find you have trouble getting your battery charged properly, try a refurbishment process to repair it.
Gel batteries are generally the same as regular lead-acid batteries you use to start your car, except the battery cells contain a gel rather than a fluid. Gel batteries are considered to be safer, because if the casing gets damaged the gel doesn't spill, but fluid-based batteries can leak sulfuric acid, if the casing gets damaged. Gel batteries are sealed units, so unlike fluid-based batteries you cannot access the cells. The best way to fix and restore a gel battery is to discharge it as much as possible and then charge the battery slowly.
Continue to charge the battery, but check it every six hours to ensure it doesn't get too hot. After 24 hours, your gel battery is fixed, restored and fully charged, so turn off the charger. Disconnect the two clamps on the battery terminals.
A gel-cell battery is different than most traditional batteries in that it is sealed and does not utilize liquid electrolytes. Rather, silica is added to the electrolytes, causing it thicken into a gel that is suspended within the battery. Because of this, gel batteries are spill-proof and more resistant to corrosion. Gel batteries, however, are generally more expensive than traditional batteries and are not able to be refilled. This also means gel batteries cannot be tested with a hydrometer. The simplest and quickest way to test your gel battery is with a digital voltmeter.
Permit the gel battery to sit for 24 hours after charging. This will allow the surface charge to dissipate and provide a more accurate reading. Retest the gel battery with a voltmeter after the 24-hour period has passed. If your gel-cell battery shows a low charge once again, chances are it will need replaced.
Most golf carts are equipped with 6-volt lead-acid batteries, which are small versions of car batteries. However, batteries in golf carts often don't last as long as they could because of neglect and improper storage. You can do several things to make a golf cart battery last longer, including reconditioning the batteries. You also can reduce problems by making sure all electrical devices on the cart are turned off when it is not in use.
Charging a 6-volt battery is no different than charging other voltage batteries, but you do need to ensure that you are using the correct charger. For example, a 6-volt lead-acid battery, such as the type sometimes used in marine vessels or RVs, needs to be charged using a suitable lead-acid charger. A nickel or lithium-based battery, such as those used to power cordless tools, must be charged using a charger designed for the correct chemical base.
Remove the battery from the charger, if your battery is nickel or lithium-based. Remove the cable clamps attached to the two battery terminals, if your battery is lead-acid.
Modern car batteries are reliable and long-lasting. When they cease to work properly, it is usually due to sulfation. Sulfation occurs when the lead electrodes in the battery become coated with sulfur from the sulfuric acid electrolyte. The primary cause of sulfation is repeated deep discharges (running the battery down). There are several methods for reversing sulfation, provided the sulfur hasn't corroded the lead plates too badly. The simplest and least expensive requires only a common household chemical and a good quality "smart" charger designed for use with car batteries.