Frequently Asked Questions


Click below to see answers to some of the questions we get asked the most. If you have a question that isn't on the list, please CONTACT US directly for our expert advice on batteries, chargers, accessories, and more.


A valve regulated lead–acid (VRLA) battery, otherwise commonly known as a sealed lead acid (SLA) battery, is a type of lead–acid battery. VRLA technology encompasses both gelled electrolyte (or gel batteries) and absorbed glass mat (AGM). Both types are regulated by special one-way, pressure-relief valves. A third type of of lead acid batteries are called flooded lead acid (FLA) or "wet cell" batteries.

AGM (Absorbed Glass Mat) Batteries:

  • The electrolyte in AGM batteries is completely absorbed inseparators consisting of matted glass fibers. This causes them to be spillproof, meaning they don’t leak acid like a flooded design if tipped on their side.
  • The glass mats in AGM batteries are wrapped around the positive plate, which helps prevent damage from vibration and extend cycling. The battery’s groups are packed tightly in the case partitions also protecting its power producing components.
  • AGM battery designs can have over twice the cycle life of a conventional flooded product in the right application.

    • Gel or Gelled Electrolyte Batteries:

  • The electrolyte in a Gel battery is permanently locked in a highly viscous gelled state instead of the traditional liquid form. Because there is no liquid-type electrolyte, it will not leak out of the battery if tipped on its side.
  • The thick, gelled electrolyte and tightly packed groups also protect the battery’s power producing components.
  • Gel battery designs have a superior deep discharge resiliency and can deliver over two to three times the cycle life of an AGM product in the right applications.

    • Flooded Lead-Acid (FLA) or "Wet-Cell" Batteries:

  • Flooded batteries hold very good rates of charge for the price, are are among the most common types of industrial batteries, but require more maintenance and care, using water to routinely replenish lost electrolytes.
  • Flooded batteries are usually not sealed, and can only be mounted in one direction to avoid any spillage.
  • Commonly utilized for storage in backup power supplies, high-availability settings like hospitals, and standalone power systems, as well as a wide variety of industrial and motor vehicle applications

  • The major difference between Gel and AGM battery performance is that a Gel battery is better suited for super-deep discharge applications, which means it can withstand deeper discharges without damaging the battery’s performance. However, due to the physical properties of the gelled electrolyte, Gel battery power declines faster than an AGM battery as the temperature drops below 32ºF (0ºC). AGM batteries excel for high current, high power applications and in extremely cold environments. AGM batteries deliver a better dual purpose solution for a combination of starting and accessory power.

  • Deep-cycle batteries typically feature thick plates with a high-density active material. The thick battery plates allow for reserve energy to be stored deep within the battery plate and released during slow discharge such as trolling or electronic instrument use. The high-density active material remains within the batteries' plate/grid structure longer, resisting the normal degradation found in cycling conditions. They are typically used where the battery is discharged to great extent and then recharged such as a battery powered trolling motor on a fishing boat.

  • Amp-Hour battery rating: This is the common rating of a battery. Amp-hour rating of battery capacity is calculated by multiplying the current (in amperes) by discharge time (in hours). Amp-hour battery rating is commonly used when describing sealed lead acid batteries used in UPS systems, emergency lights and wheelchairs. For example: a battery which delivers 2 amperes for 20 hours would have a 40 amp-hour battery rating (2 * 20= 40).
  • Cold Cranking Amperage battery rating: CCA is the discharge load in amps which a battery can sustain for 30 seconds at 0°F. and not fall below 1.2 volts per cell (7.2V on 12V battery). This rating measures a burst of energy that a car needs to start on a cold morning. This rating is used mainly for rating batteries for engine starting capacity and does not apply to NiCad batteries, NiMH batteries or alkaline batteries.
  • Reserve capacity battery rating: RC is the number of minutes a new, fully charged battery at 80°F. will sustain a discharge load of 25 amps to a cut-off voltage of 1.75 volts per cell (10.5V on 12V battery). This rating measures more of a continuous load on the battery.

  • The calculation used to determine watt hours is: Volts x ampere hour (Ah) = watt hours (Wh)

  • Cycle life is measured by the amount of times a battery may be charged and discharged. Every time a battery is charged and discharged, it uses one cycle. Cycle life is very important in battery applications such as laptop batteries and emergency light batteries. For example, a NiCad battery has a cycle life of 500-1000 or more cycles.

  • If the Ah/mAh rating is different, it will that not typically impact your battery's performance. There can be slight variances in rated capacities between batteries that perform the same within an application. The rated capacity of a battery is often set to a standard, either over a 15 minute, 8 hour, or 20 hour rate. Some batteries can perform just as well as others despite having a different capacity rating. Contact our battery specialists to help determine if our battery will meet your needs and specifications.

    • NOTE:
    When interconnecting batteries (cells), they must be identical in voltage and amp rating

    Batteries connected in series:

  • The positive terminal of the first battery is connected to the negative terminal of the second battery; the positive terminal of the second is connected to the negative of the third, and so on. The voltage of the assembled battery is the sum of the individual batteries.
  • The batteries are connected: ✚ to ⚊ to ✚ to ⚊ to ✚ to ⚊, etc. The capacity of the battery is unchanged.

    • Batteries connected in parallel:

  • The positive terminal of the first battery is connected to the positive terminal of the second battery, the positive terminal of the second is connected to the positive of the third; the negative terminal of the first battery is connected to the negative terminal of the second battery, the negative terminal of the second is connected to the negative of the third and so on.
  • The batteries are connected: ✚ to ✚ to ✚ and ⚊ to ⚊ to ⚊. In this configuration, the capacity is the sum of the individual batteries and voltage is unchanged.
  • For example, (5) 6V 10AH batteries connected in series produces a battery array that is 30 Volts and 10AH. Connecting the batteries in parallel produces a battery array that is 6 Volts and 50AH. Ordinary auto batteries are designed in the same fashion. Six 2-volt cells are arranged in series to produce a 12v battery. Many NiCad batteries are arranged in the same way.

  • Overcharging occurs when the total capacity removed has been replaced by recharging and the battery remains on charge. This overcharging creates excessive heat that can cause the battery plates within the cells to buckle and shed their active material. The battery will react to the overcharge by producing an excessive amount of hydrogen and oxygen. These gases are the result of the breakdown of the water molecules within the electrolyte. The water that has been displaced by overcharging can be replaced in a serviceable (non-sealed) battery, but, in the maintenance-free sealed batteries, permanent capacity loss will result.
  • Excessive battery discharging can cause damage to a battery. The amount of discharge a battery can have without damage depends upon its chemistry. In general, a lead acid battery will not tolerate as deep a discharge as a NiCad or NiMh battery. Sealed lead acid batteries function best if they are discharged to only about 85% of nominal voltage (10.2V on 12V battery).

  • Sulfation is the formation or deposit of lead sulfate on the surface and in the pores of the active material of the batteries' lead plates. If the sulfation becomes excessive and forms large crystals on the plates, the battery will not operate efficiently and may not work at all. Common causes of battery sulfation are battery inactivity in a discharged condition, operating the battery at excessive temperatures, and prolonged under or over charging.

  • Sealed lead acid
  • Flooded lead acid (automotive type)
  • NiCad
  • Alkaline
  • Silver oxide
  • Lithium
  • Manganese-dioxide
  • Zinc-air
  • NiMH