Motorcycle Battery Types
There are three major types of motorcycle batteries: conventional “wet cells” with liquid electrolyte, gelled electrolyte (gel cells), and absorbed glass mat (AGM) or “dry cells.” Wet-cell batteries with removable caps contain lead-antimony and are the least expensive, but require periodic refilling. Wet batteries marked “maintenance-free” with semi-removable caps usually contain lead-calcium plates that use less water, although in some cases, they can still run dry. Gel batteries contain a jellied electrolyte that doesn’t splash easily. Gel cells are more tolerant of being left partially discharged and they don’t self-discharge fast, but they cost more than conventional batteries. The most expensive type is absorbed glass mat, which uses silica-glass matting that makes them maintenance-free. While AGM batteries typically cost more, they have higher efficiency and power than other types, are the most resistant to vibration, and usually last considerably longer.
Absorbent Glass Mat (AGM):
AGM technology became popular in the early 1980s as a sealed lead acid battery for military aircraft, vehicles and UPS to reduce weight and improve reliability. The sulfuric acid is absorbed by a very fine fiberglass mat, making the battery spill-proof. This enables shipment without hazardous material restrictions. The plates can be made flat to resemble a standard flooded lead acid pack in a rectangular case; they can also be wound into a cylindrical cell.
AGM has very low internal resistance, is capable to deliver high currents on demand and offers a relatively long service life, even when deep cycled. AGM is maintenance free, provides good electrical reliability and is lighter than the flooded lead acid type. While regular lead acid batteries need a topping charge every six months to prevent the buildup of sulfation, AGM batteries are less prone to sulfation and can sit in storage for longer before a charge becomes necessary. The battery stands up well to low temperatures and has a low self-discharge.
The leading advantages of AGM are a charge that is up to five times faster than the flooded version, and the ability to deep cycle. AGM offers a depth-of-discharge of 80 percent; the flooded, on the other hand, is specified at 50 percent DoD to attain the same cycle life. The negatives are slightly lower specific energy and higher manufacturing costs than the flooded, but cheaper than the gel battery.
Most AGM batteries are mid-sized and range from 30 to 100Ah. They can also be found in UPS, big and small for stationary and deep cycle use. They are commonly built to size and are found in high-end vehicles to run power-hungry accessories such as heated seats, steering wheels, mirrors and windshields. NASCAR and other auto racing leagues choose AGM products because they are vibration resistant.
AGM is the preferred battery for upscale motorcycles. Being sealed, AGM reduces acid spilling in an accident, lowers the weight for the same performance and allows installation at odd angles. Because of good performance at cold temperatures, AGM batteries are also used for marine, motor home and robotic applications.
A gel battery, also known as a “Gel Cell”, is a VRLA (valve-regulated lead–acid ) battery, a type of Sealed Acid Battery. The technology used in making gel cells is similar to AGM batteries. However, instead of utilizing the Absorbent Glass Material that AGM batteries use, gel batteries make use of gelled electrolytes. The solidified electrolytes reduce the risk of spillage and evaporation that results in corrosion problems.
Compared to ordinary batteries, gel batteries are much lighter. This technology only uses a small amount of solidified electrolyte to keep the acid immobile. Gel batteries have longer lifespan than traditional batteries; this is due to the fact that the gelled solution can hold their charge for a longer time. This battery type is also durable and can withstand extreme ranges in temperature.
A wet–cell battery is the original type of rechargeable battery. It is commonly found in aviation, electric utilities, energy storage and cellphone towers. The battery contains a liquid electrolyte such as sulfuric acid, a dangerous corrosive liquid