Can I Use My Battery Charger on AGM Batteries?

What’s a battery without a charge? In order to keep your battery operating in prime condition, MK Battery offers a variety of battery chargers. But what if you already have a battery charger? Do you need to buy a new one just because you bought a new battery? 

The truth is that it will depend on a number of factors, from the use that your battery is being put to, to the style of battery and the charge it needs. That being said, there’s one rule that you should remember: a battery charger specifically made only for flooded cell batteries should NOT be used on VRLA batteries (including gel and AGM batteries). 

The Difference Between VRLA Batteries and Flooded Cell

There are two major categories of lead acid batteries: flooded cells and valve-regulated lead acid batteries (or VRLA batteries). Flooded cells use a free-flowing liquid electrolyte, whereas VRLA batteries have a stabilized electrolyte–either through suspending it in gel form (gel battery) or absorbing it in a glass mat (absorbed glass mat, or AGM battery). For this reason, VRLA batteries are also sometimes known as sealed lead acid batteries. Although flooded cell batteries are still in common use today because of their affordability and their ability to deliver a big initial charge, they also require more maintenance, more ventilation, and tend to lose their charge faster. 

Both AGM and gel batteries are naturally more stable and have much lower discharge rate than flooded cell batteries. They also have different needs from flooded cell batteries, and a charger configured for flooded cell batteries may burn out VRLA batteries, and cause them to die. 

How to Charge AGM and Gel Batteries Effectively

VRLA batteries, like AGM and gel batteries, were designed to absorb charges gradually and slowly, and discharge in the same way. That’s why they’re less commonly used in situations that require high cranking amperes (i.e. to start a boat), and more often in deep cycle uses when steady, reliable power is needed (i.e. to power a motorized wheelchair). 

Overcharging an AGM battery can lead to reduced battery life. Many modern chargers allow you to select whether you’re charging an AGM battery or a flooded cell option. However, as stated above, it’s important not to use an old charger specially formulated only to suit the needs of wet cell batteries if you have a VRLA battery. 

What About Trickle Chargers? 

Trickle chargers are useful for keeping your battery alive when it’s in storage. If the battery is dormant for a long time and it has a high risk of being over-discharged, the charger will top it off as needed. 

This is most commonly needed for flooded cell or wet cell batteries, which tend to have a higher discharge rate than newer VRLA batteries. Our MK Battery products have some of the lowest resting discharge rates in the industry, making trickle chargers obsolete. However, if you have a special situation, you can always call our battery specialists at 800.372.9253 and we’ll be happy to answer any questions you may have.