What are some of the major types of lead acid batteries?
Batteries are divided in two ways, by application (what they are used for) and construction (how they are built). The major applications are automotive, marine, and deep-cycle. Deep-cycle includes solar electric (PV), backup power, and RV and boat "house" batteries. The major construction types are flooded (wet), gelled, and AGM (Absorbed Glass Mat). AGM batteries are also sometimes called "starved electrolyte" or "dry", because the fibreglass mat is only 95% saturated with Sulphuric acid and there is no excess liquid. Flooded may be standard, with removable caps, or the so-called "maintenance free" (that means they are designed to die one week after the warranty runs out). All gelled are sealed and a few are "valve regulated", which means that a tiny valve keeps a slight positive pressure. Nearly all AGM batteries are sealed valve regulated (commonly referred to as "VRLA" - Valve Regulated Lead-Acid). Most valve regulated are under some pressure - 1 to 4 PSI at sea level.
What is a Starting battery?
Starting batteries (sometimes called SLI, for starting, lighting, ignition) are commonly used to start and run engines. Engine starters need a very large starting current for a very short time. Starting batteries have a large number of thin plates for maximum surface area. The plates are composed of a Lead "sponge", similar in appearance to a very fine foam sponge. This gives a very large surface area, but if deep cycled, this sponge will quickly be consumed and fall to the bottom of the cells. Automotive batteries will generally fail after 30-150 deep cycles if deep cycled, while they may last for thousands of cycles in normal starting use (2-5% discharger).
What is the proper electrolyte level?
Liquid levels should be 1/8 inch below the bottom of the vent well (the plastic tube that extends into the battery). The electrolyte level should not drop below the top of the plates.
Are lead acid batteries recyclable?
Lead is the most recycled metal in the world today. The plastic containers and covers of old batteries are neutralized, reground and used in the manufacture of new battery cases. The electrolyte can be processed for recycled waste water uses. In some cases, the electrolyte is cleaned and reprocessed and sold as battery grade electrolyte. In other instances, the sulphate content is removed as Ammonia Sulphate and used in fertilizers. The separators are often used as a fuel source for the recycling process.
