battery pack capacity infograph

Battery Pack’s Size Impacts Capacity And Run-Time

Having to buy a new set of batteries for your golf car is not something people always look forward to. A 48-volt golf car can take anywhere from four or even eight batteries, depending on the compartment space and vehicle model. This can be a big investment, so if you could get away with only buying four 12v batteries, would that be better? It might seem so upfront, but depending on how often you use your golf car and the amount of runtime you expect, fewer batteries with the same voltage may not always be the best choice.

Depending on the make and model of your golf car, it may seem less expensive to buy four 12-volt batteries connected in series to power a 48-volt system. Choosing higher voltage deep-cycle batteries, however,  often means sacrificing amp-hour capacity. Under constant use, a four-battery pack will have a shorter life cycle than a pack producing the same 48-volts but made up of more batteries. The reason is that the larger battery pack provides a substantial increase in amp-hour capacity, leading to more runtime and cycle life than a smaller battery pack.

More batteries connected in series can produce the same amount of voltage, but because there are more batteries to share the load, it lowers the discharge rate per battery. The driving range is also extended because more batteries increase the overall capacity. Think of it like adding a larger fuel tank to your car. With a larger battery bank, you can drive your golf car farther between charges. If you keep your depth of discharge (DOD) on the battery pack less than 50 percent, it will ultimately add to making the pack last much longer than a pack with fewer batteries.

For example, on a 48-volt golf car, you can typically get a longer driving range and increased battery life with six 8V batteries, and even more capacity with eight 6V batteries. There are still other variables to consider, as there are various 6V and 8V batteries with different amp-hour ratings, but when you replace the batteries with the same amp-hour rating required by the golf car manufacturer and provide proper maintenance procedures, the battery bank with more batteries will last longer. Additional information on explaining the effects of wiring batteries in series and parallel can be found here: https://www.usbattery.com/info-center/configuration/

Connected 8v Batteries

SpeedCaps™ For Your Deep-Cycle Battery

U.S. Battery SpeedCaps™ Go Beyond Venting Deep-Cycle Battery Cells

The vent caps used on deep cycle batteries are designed to allow the escape of gases formed inside the battery when it is being charged and to limit the escape of electrolyte in normal operation. The vent caps are also designed for easy removal to visually check the electrolyte level in the battery and to add water as necessary.   They also allow for the insertion of a hydrometer to check the battery’s state of charge.  During regular maintenance that requires removing and reinstalling the vent caps, there is a possibility that the vent caps may not be properly reinstalled.  This could allow electrolyte to spill over onto the battery and cause corrosion on terminals and surrounding areas.

To improve on the standard battery vent cap, U.S. Battery SpeedCaps™ are designed with a cantilever-style closure that is attached to three or four battery cell caps. This design allows all the caps to be easily removed with a single twist. The design not only makes the removal of the battery caps easier, but it also ensures that they are properly seated when being replaced. The locking ramp on top self-adjusts to maintain compression between the sealing gasket and vent well surface for the life of the battery. SpeedCaps™ are designed to make your job of battery maintenance as hassle-free as possible while also maintaining a proper seal and gas venting during use.CAD drawing of U.S. Battery SpeedCaps

Proper venting is critical during charging when gas is being generated within the electrolyte and bubbles to the surface, helping to mix the electrolyte. To prevent electrolyte from escaping past the vent caps, U.S. Battery SpeedCaps™ feature 0.750-inch diameter porous discs that assure proper venting while maintaining flame retardance to prevent gas ignition inside the battery. They also have four separate vent holes that decrease backpressure and prevent internal pressure buildup.

Since vent caps are removed and replaced frequently during regular battery maintenance, U.S. Battery SpeedCaps™ are designed with a larger diameter flange. The enlarged flange ensures even pressure on the surface of the sealing gasket while maintaining a tight fit between the barrel and cylinder to eliminate side-to-side movement and the chance for misalignment of the gasket onto the sealing surface.

To prevent spilling of the electrolyte during vehicle movement in golf carts, aerial platform lifts, RVs, boats, etc., the SpeedCap™ design also features a double-sided internal baffle with multi-directional channels and a sloped center hole return drain, all designed to route battery electrolyte back into the cell.

With all these safeguards in place, U.S. Battery SpeedCaps™ are an example of one of the many details the company adds to its products to ensure they provide optimum performance and cycle life compared to other deep-cycle batteries on the market.

AGM and Flooded Deep-Cycle Batteries

Understanding the Differences Between AGM And Flooded Deep-Cycle Batteries

When it comes to powering electric vehicles like golf carts, deep-cycle lead-acid batteries are the industry standard. The reason is that they are designed to provide the most cost-effective energy storage and delivery over the life of the battery.

Over the years, there have been two main types of deep-cycle lead-acid batteries that many golf car owners and fleets have used, the Flooded Lead-Acid (FLA) battery and the Absorbed Glass Mat (AGM) battery. While both provide optimum performance in a wide variety of applications, their design difference can offer various advantages depending on the application.

Engineering

The main design difference between FLA and AGM batteries is how the electrolyte is managed. In FLA batteries, the battery plates are submerged in the liquid electrolyte. During use, water in the electrolyte is broken down into oxygen and hydrogen gases and water is lost. This requires regular additions of water to be replaced to keep the battery plates fully submerged in the electrolyte.

In AGM batteries, the electrolyte is absorbed in special glass mat separators that retain all the electrolyte needed for the life of the battery.  Since there is no free electrolyte, the oxygen generated on a charge is recombined at the negative plate.  In normal operation, hydrogen is not generated and no water is lost.  This eliminates the need to add water and also allows the battery to be sealed with a one-way valve that prevents leakage of the electrolyte.

Performance Differences

FLA batteries have been used in a wide variety of applications for well over 150 years. Their popularity comes from their safety, reliability, and cost-effectiveness when compared with other types of rechargeable batteries.   According to Fred Wehmeyer, U.S. Battery Senior VP of Engineering, FLA batteries deliver the lowest cost per watt-hour both in acquisition cost and in overall cost per charge/discharge cycle.  “This is why they are the best choice for fleets of vehicles or equipment that are used heavily on a daily basis,” says Wehmeyer. “Also, both FLA and AGM batteries offer an environmental advantage over other types of batteries because they are essentially 100 percent recyclable and enjoy the highest recycling rate of any commercial product.”

AGM batteries offer the advantage of being maintenance-free. This can be significant in applications where regular maintenance is difficult or costly, such as when the batteries are located in remote or hard to access locations. Even though AGM batteries cost more per watt-hour, the elimination of maintenance costs reduces the overall battery operational costs.  Also, since the battery is sealed and does not emit gases in normal use, it can be used in sensitive areas such as food or pharmaceutical storage facilities.

Selecting between FLA or AGM deep cycle batteries ultimately depends on the type of use and the capability to provide regular maintenance in the application.

AGM = No Maintenance + Higher Cost + Susceptible to abuse like overcharging

FLA = Requires Watering + Lower Cost + Susceptible to abuse from poor maintenance

No matter what type of battery you use, it is always best to target the depth of discharge to 50 percent or less for both FLA or AGM battery types. This will optimize battery life cycle cost vs acquisition cost over the life of the battery system.