Gel Lead Acid Batteries

InThe gel lead acid battery is a part of the VRLA battery (A valve-regulated lead-acid battery) – also referred to as SLA (sealed lead-acid).There are three main types of VRLA batteries which are AGM (absorbent glass mat), sealed VR wet cell and gel cell. Gel lead acid cells are sometimes referred to as "silicone batteries".

Gel lead acid batteries technology

First, the gel lead acid battery was introduced in the 1950s but became popular in the 1970s. Sulfuric acid is mixed with a silica gelling agent which converts the liquid electrolyte into a semi solid paste which makes the gel maintenance free. The Gel batteries are usually used in UPS applications. Also, the flooded lead acid is most durable when used as standby operation (in terms of suitability and cost), but requires regular maintenance and top ups and so has high operational cost. Gel lead acid battery has lower cost than flooded batteries and is the preferred battery type for the UPS installations in communication systems. AGM has a lower cost and has higher load capabilities as well to Gel lead acid batteries. The two systems have a great future and will keep serving as standby applications which need limited deep cycling.

Advantages of the Gel lead acid batteries

The main advantages of the Gel lead acid batteries are:

• Maintenance free system, can be mounted sideways, low self-discharge
• High tolerance to heat and mechanical strength
• High cycle count
• Large range of battery sizes available for various applications
• High durability because of the ability to transfer heat to the outside
• Long life cycle with high performance
• Less dry out than the AGM type
• Safe for all operation and can withstand abuse

Limitations of the Gel lead acid batteries

The main limitations of the Gel lead acid batteries are:

• High cost of manufacturing when compared to AGM
• Average load current and specific energy
• Good ventilation is always required as it can release gases
• High Sensitivity to overcharging
• Gel lead acid batteries must be stored in a charged state

Use of Gel lead acid batteries in UPS

ESS (Energy storage systems) used for energy buffering and frequency regulation use lithium ion batteries. In addition, Li-ion can be rapidly charged using available excess energy is available, unlike lead acid batteries. UPS for standby applications are still served by lead acid batteries because of their low cost, durability and increased safety, as the UPS is typically is only discharged occasionally and dwells at full charge.