Written By Marina Dawson

Most battery users are aware that they are using a lead-acid battery, however did you know that there are actually several different types of lead-acid batteries?  Since each type of battery brings its own strengths and weaknesses, it is a good idea to have an understanding of the different types prior to purchasing a new one.  Additionally, different battery technologies may need different charging systems, so be sure to plan ahead and confirm with the manufacturer that your current battery charger will be sufficient.  Using the wrong charger can cause premature battery failure and will affect the life cycle of your battery.

The standard lead-acid battery most commonly in use is a wet cell, or flooded, battery.  These batteries are made with lead plates that are coated with chemicals, and then set inside the electrolyte solution inside the battery.  As a rule of thumb, the larger the plates in the battery, the longer it will be able to supply a current.  As these batteries are discharged, the water in the electrolyte solution evaporates, causing the battery to dry out and fail.  With these batteries it is important to check the electrolyte levels and add distilled water when they start to drop too low.  Many people prefer the serviceable style of the flooded battery because these allow you to open the battery and add water when necessary.  The maintenance free versions are completely sealed so that when the battery dries out there will be no way to replace the water and the entire battery will need to be replaced.  Flooded batteries also give off hydrogen gas which, in addition to causing corrosion on the battery terminals, can also be a fire hazard.

Another type of lead-acid battery is the gel cell.  These batteries contain an electrolyte solution that is made with a gelatin like substance which prevents spillage should the battery be flipped upside down.  Because of this durability, they are particularly good for boats and other marine toys.  The solution in a gel cell battery does not evaporate due to a mixture of oxygen and hydrogen gasses that combine inside the battery when it is being discharged.  However, some hydrogen gas can escape through the vents in the battery, and if this happens it creates a highly flammable situation where ignition should be avoided.  Gel cell batteries also require a special charging system and tend to have a lower reserve capacity than a flooded cell battery, so they are not for everyone.

Absorbed glass mat (AGM) batteries are similar to gel cell batteries in that they suspend the electrolyte solution eliminating the need for water.  They are also sealed, and use the mixture of hydrogen and oxygen gasses to keep the lead plates moist.  However, they actually contain no free liquid, as there is a special glass mat that acts as a sponge between the lead plates.  This contains the electrolyte, keeping it constantly in close proximity to the lead plates.  AGM batteries can offer twice the normal life cycle of a gel cell, however they too require thoughtful charging, as using an incorrect current will significantly affect the life cycle of the battery.

Although flooded lead-acid batteries remain the most common in North America due to their low cost and wide distribution, allowing them to be easily replaced, it is important to realize that your options are not limited to this type of battery.

© 2008 BatteryChargerStore.com