Lead-acid battery construction, chemistry and application

There are many different batteries currently in production in the world.

Lead-acid batteries can be first described by type or construction:

Sealed Valve Regulated or Starved Electrolyte batteries

Sealed Valve Regulated Lead-acid (VRLA) or starved electrolyte AGM or GEL types use a solution of sulfuric acid and water completely suspended into a gel-like material using silicate additives or absorbed into a woven glass fibre mat (AGM). There is no excess electrolyte to leak out even if tipped or turned upside down. This sealed nonspillable characteristic is a product of the construction and chemistry of the battery design.

Sealed maintenance-free and accessible maintenance-free flooded batteries

Sealed maintenance-free flooded and accessible maintenance-free flooded types use a solution of sulfuric acid and water that can spill out of the battery if tipped. Even though the sealed maintenance-free flooded batteries are not accessible, electrolytes will eventually leak out through the central degassing manifold vents if tipped. Some maintenance-free flooded batteries have removable filler caps making the battery accessible.

Maintenance required batteries

These 2V, 6V or 12V industrial, commercial, general-purpose deep-cycle and hybrid batteries use a solution of sulfuric acid and water that can spill out of the battery if tipped. These batteries generally require high levels of watering and maintenance.

Lead-acid battery chemistry

A battery can be described by the chemistry of the alloys used in the production of the batteries' grids or plates:

• Lead Calcium alloys. Primarily used in maintenance-free starting batteries.
• Lead Calcium/Antimony hybrid alloys. Principally used for commercial vehicle starting.
• Lead High Antimony and/or Lead Low Antimony alloys. Used for general-purpose deep-cycle batteries to support motor controllers or inverters.

Amongst other things, the alloy (chemistry) used in the production of the battery grid, paste and final plates will dictate how well the battery will cycle, how long it will live when properly maintained, how much it will gas when being discharged and charged and how much water it will use as it works. Calcium alloys will use less water and will live better in heat. Batteries made with semi-traction industrial-type calcium plates will have the advantage of long life in deep-cycle applications and eliminate maintenance requirements. Batteries with higher Antimony alloys will generally deliver good to excellent cycle life but will use more water in the process requiring rigorous maintenance schedules to realize actual design life. Hybrid alloys will perform somewhere in between, closer to the calcium alloy spectrum.

Lead-acid battery applications

Batteries can be referred to by the application they were designed for. These applications will range from pure starting to pure cycling or deep cycling and float service or standby/backup power (many application requirements are somewhere in between).

• Starting batteries. For engine starting and ignition applications.
• EFB batteries. For micro-cycling in Start-Stop engine technology.
• Float batteries. For UPS/Telecom or standby backup power applications.
• Cyclic batteries. For light-duty lighting and accessory loads in RV and marine applications.
• Renewable energy batteries. For long life, high cycle use in off grid applications.
• Deep-cycle batteries. For medium-duty loads in general-purpose golf carts, marine, RV and renewable energy applications.
• Commercial Semi-Traction batteries. For heavy-duty high-rate deep cycling loads in commercial applications.
• Industrial Traction. For heavy-duty use in industrial equipment such as electric forklifts.