VRLA Batteries

Firstly, VRLA stands for Valve Regulated Lead Acid, and are also referred to as a sealed lead acid or SLA battery.  They are created by using a limited amount of electrolyte which is absorbed in a plate separator or formed into a gel. There is a proportioning of the negative and positive plates so that oxygen is recombined within the cell, with a relief valve that retains the battery contents independent of the position of the cells.

VRLA is short for Valve Regulated Lead Acid, a special type of lead acid battery that was first developed in the mid 1960s. The key difference between VRLAs and traditional flooded lead acid batteries is that they’re completely sealed, which is why they’re alternatively known as Sealed Lead Acid (SLA) batteries. Since they are sealed, VRLA batteries are essentially spill-proof, which allows them to be mounted in a variety of positions that aren’t possible with flooded batteries. Another difference lies in how the batteries’ electrolytes are maintained. When a flooded battery is charged, it loses water due to the evaporation of gasses. This requires you to replace the lost water by topping off the electrolyte inside with distilled or deionized water. VRLA batteries, however, are equipped with a one-way pressure relief valve that prevents gas from escaping. When the battery charges, the gasses recombine into water via a process called oxygen recombination. This makes a VRLA battery completely maintenance free.

There are two types of VRLA batteries: AGM and gel. The big difference between the two lies in how their electrolyte is stored. In a flooded battery, the electrolyte is a free-flowing liquid. In an AGM (short for Absorbed Glass Mat) battery, the electrolyte is absorbed in a series of fiberglass separators, set between the battery’s plates and held there in suspension. In a gel battery, the sulfuric acid in the electrolyte is mixed with a silica additive, which transforms the electrolyte into a thick gel-like substance.

AGM batteries perform best in high current, high power applications, such as starting batteries for cars and other vehicles. They’re also quite popular with boat and RV owners, since an AGM battery can serve as a dual purpose battery, providing the strong starting power needed to start an engine, as well as the cycling capacity to run additional accessories. Gel batteries can discharge much deeper than AGM batteries can. This makes them ideal for cycling operations that require heavy, everyday use. Some common uses for gel batteries include: marine trolling motors, wheelchairs & mobility scooters, marine & RV house power, UPS and other backup applications. One thing to keep in mind is that gel batteries don’t perform well in cold temperatures since their power declines much faster than an AGM once the temperature drops below 32℉.

AGM and Gel refer to the type of SLA battery construction. AGM batteries suspend an electrolyte in a glass mat, which leads to faster charging and makes AGM the preferred choice for starter applications. Gel suspends the electrolyte in a gel like paste, and is often used for smaller, lower capacity applications

In comparison to traditional flooded lead acid batteries, like the ones used in forklifts and pallet trucks, yes they are, but that doesn’t mean you can neglect them. They don’t need vrla monitoring or watering in quite the same way as non-vrla batteries do. However, they should always be kept clean, using an industrial cleaner and degreaser to keep the connectors and terminals free from any corrosive elements. They should periodically be checked for both charge and functionality to keep them performing correctly.

VRLA batteries are typically available with a design life ranging from 3 to 10 years but as with all lead acid batteries, their maximum life depends on how well you look after them. The single biggest killer of VRLA batteries is over-discharge. If you leave a VLRA battery, of any kind, in a chronically over discharged state, then hydration occurs. Hydration is when the lead and lead compounds of the plates dissolve in the water of a discharged cell and form lead hydrate, which is then deposited on the separators. When the cell is recharged, multiple internal short circuits occur between the positive and negative plates. Once hydration is evident, the cell is permanently damaged. You can’t see if hydration has happened because the containers are opaque and hydration can occur after just one major over-discharge event. To make sure you get the maximum amount of cycle out of a VRLA battery, and to avoid over-discharge events, you should use a low voltage alert which gives visual and audible alerts when a VRLA battery is about to be critically over-discharged.

• Marine Trolling
• Electronics
• Sailboats
• Small Electric Vehicles
• Wheelchairs/Scooters
• Golf Cars
• Portable Power
• Floor Scrubbers
• Personnel Carriers
• Renewable Energy (Solar, Wind)
• Village Power
• Marine & RV House Power
• Commercial Deep Cycle Applications

Standby and Emergency Backup Applications

• UPS (Uninterrupted Power Systems)
• Cable TV
• Emergency Lighting
• Computer Backup
• Renewable Energy (Solar, Wind)
• Frequency Regulation
• Telephone Switching

Other Applications

• Race or High Performance Cars
• On-Highway Trucking
• Off-Road Vehicles
• Wet Environments
• Marine & RV Starting
• Diesel Starting
• Cars and Light Trucks with Accessories
• Vehicles with Start-Stop Systems
• EVs (12-volt System)