Defining VRLA Batteries, AGM Batteries And TPPL Batteries

Distributors are an important resource for customers switching from flooded lead acid batteries to sealed lead acid batteries, or for those purchasing equipment that runs on sealed batteries. Educating customers on the different types of sealed battery technology can help them choose the right one for their floor cleaning needs.

VRLA batteries come in two types: Absorbent Glass Mat (AGM) batteries and gel batteries. According to Chad Uplinger, general manager for specialty markets for EnerSys, Reading, Pennsylvania, gel batteries are used in applications such as forklifts and some floor care equipment in Europe, but these types of batteries are not typically used for floor care machines in the United States.

“In the past the industry has tried to go to gel,” says Uplinger. “The problem with gel batteries is they don’t typically discharge deeply and end up drying out, so people replace them a lot faster than flooded.”
 
Today, the majority of sealed batteries produced are AGM batteries. These batteries use a glass mat to absorb the electrolyte, whereas gel batteries use a gelling agent added to the electrolyte to reduce movement.

“If you look at a typical flooded battery, it has a positive electrode and a negative electrode, and a separator in between the electrodes so that they don’t touch each other,” says Wehmeyer. “This serves two functions: it separates the electrodes and allows electrolyte to pass between the positive and negative electrodes, so it has to be porous. The biggest difference between the flooded and sealed battery is the sealed battery needs to use a separator that is able to contain all the electrolytes within the separator matrix, so that requires a high degree of absorbency. That’s where the absorbent glass mat comes in.”

AGM batteries can either be thin plate pure lead (TPPL) or traditional thick plate technology. Thick plate AGM batteries are made with an alloy of lead, calcium and tin, whereas TPPL batteries are 100 percent pure lead or close to 100 percent pure lead.

Some battery manufacturers favor thick plate AGM batteries for floor care equipment, because they are suitable for deep-cycle applications in which the battery is deeply discharged using most of its capacity on a regular basis.

Although TPPL batteries are typically used for starter applications in mechanized vehicles, EnerSys also manufactures a cycling line of TPPL batteries suitable for floor cleaning equipment. According to Uplinger, a TPPL battery has twice the number of charge cycles as a flooded battery.

One of the unique benefits of a TPPL battery, says Uplinger, is its quick charge time, which can be a selling point for certain cleaning applications. And although TPPL battery use for floor care is in its infancy, he is seeing growing interest in the technology from original equipment manufacturers.

EnerSys is in the process of installing and testing TPPL batteries in floor cleaning equipment at John F. Kennedy International Airport in New York.

“[The customer] can only use their floor machines between midnight and 6 a.m. We’re going to install TPPL batteries in the machines, run them for 2.5 hours, and then fully recharge the batteries so they can run them a second time in the same night,” says Uplinger. “Right now they’re using flooded batteries, and it takes 10 hours to recharge the machines. So rather than buy a new machine, they’re going to use the same machine twice in one shift.”