Choose the right Trojan battery for your applications

Selecting the Proper Lead-Acid Technology

With so many different battery technologies on the market today, it can be difficult to make sure you’re selecting the right battery for your application. This document will describe the basic types of lead-acid batteries available, and help you understand which one will provide the best performance and value for your needs.

Trojan Flooded (Wet)

The flooded lead-acid (FLA) battery, invented in 1859, was the firstrechargeable battery. After decades of refinement, it remains the primary choice for many applications. The battery plates are immersed in an electrolyte of dilute sulfuric acid, and removable caps in the lid allow replacement of lost water. FLA batteries are cost effective, rugged, and provide reliable performance when properly maintained.

Because FLA batteries are not sealed, they must be kept in the proper orientation (upright) to avoid spilling of electrolyte. Due to the risk of spills, they cannot be shipped by air.

During the charging process, FLA batteries consume water and release hydrogen gas, which must be properly vented to avoid potential fire hazards. The water consumed during charging must periodically be replaced at a frequency that varies with the usage profile.

Although the introduction of single-point watering systems has reduced the overall effort to water FLA batteries, this periodic requirement means that these batteries are appropriate only in situations where regular maintenance can be assured. With proper maintenance and charging, flooded batteries can provide years of reliable service in many applications.

Trojan Absorbed Glass Mat (AGM)

The AGM battery is a sealed battery that fits into the category of Valve-Regulated Lead Acid (VRLA) batteries. These batteries are designed so that hydrogen and oxygen are recombined within the battery, rather than being vented. A built-in valve will release excess gas in case of a severe overcharge.

An AGM battery is constructed by compressing a glass fiber mat between each plate. The glass mat holds electrolyte in place much like a sponge, and helps support the plates. This gives AGM batteries good resistance to shockand vibration.

Since AGM batteries are sealed, they can be mounted on their sides if desired and ventilation requirements are much less demanding than with flooded batteries. They can be shipped by air if needed. They have the ability to charge and discharge at high rates and perform well at low temperatures.

It is very important that AGM batteries not be severely overcharged, as this will cause the battery to rapidly dry out. The selected charger must specifically have an AGM setting to avoid damaging the battery.

Trojan Gel

A Gel battery is another type of VRLA battery, and like the AGM, is sealed. Although the basic internal construction of a Gel battery is similar to that of the flooded battery, the electrolyte has been immobilized by the addition of a thickening agent, taking on the look and consistency of petroleum jelly. Like the AGM, it can be mounted on its side and doesn’t release hydrogen during normal operation.

Gel batteries have a higher initial cost, and typically don’t work as well in higher power applications. In deep-cycle applications, they will generally outlast an AGM battery, unless the AGM has been designed for deep cycling. Like the AGM, the selected charger must have a specific Gel setting to avoid overcharge damage. Additionally, the charger and charge algorithm should support temperaturecompensated charging. Since Gel batteries are resistant to spills and leakage, they can also be shipped by air.