Sealed Lead Acid Battery Overview
Sealed lead-acid batteries are the primary type of battery, widely recognized for their wide range of applications, including uninterruptible power supplies (UPS), automotive, medical equipment, and telecommunications. Each battery consists of multiple cells, each containing plates submerged in a dilute sulfuric acid electrolyte.
Battery Terminals
Depending on the specific model, Cohen batteries have a variety of terminal types. These include AMP Faston-type terminals made of tinned brass, post-type terminals using the same material with threaded nuts and bolts hardware, and rugged flag-type terminals made of lead alloy. Specialized epoxy is used as a sealing material around the terminals.
Battery plates (electrodes)
Using cutting-edge technology, Cohen casts the grid from an antimony-free lead-calcium alloy. The minimal addition of calcium and tin to the grid alloy enhances the strength of the electrode plates and ensures that they remain durable under frequent cycling. The grids are coated with a lead dioxide paste to form an electrically active material. In the charged state, the negative plate consists of pure lead, and the positive plate consists of lead dioxide, both of which are porous or spongy to optimize surface area and maximize capacity. The heavy-duty lead-calcium alloy grids in cycling and float applications provide additional performance margins and longevity with rapid recovery after deep discharge.
Electrolyte
The electrolyte used is fixed dilute sulfuric acid (H2SO4).
Battery Safety Valve
A safety valve is activated to release the pressure to control excessive gas pressure in the battery. This one-way valve not only prevents air from entering the battery and preventing oxygen from reacting with the plates to cause internal discharge, it also serves as a critical safety feature in the event of overcharging. The vent release pressure range is 2 to 6 psi and the seal is made of neoprene.
Battery Separators
Cohen’s lead-acid battery separators are made of non-woven fiberglass cloth that is highly resistant to heat and oxidation. This material excels in electrolyte absorption and retention while providing excellent ionic conductivity.
Battery Container and Case Sealing
Battery boxes and lids are made of impact-resistant ABS resin, which is extremely chemical resistant and flame retardant. Battery cases and lids are made of non-conductive ABS plastic that meets UL94-HB standards (e.g., PS-1270 models) or UL94 V-0 standards (e.g., PS-1270 FR models). Depending on the specific model, the enclosure sealing process may involve ultrasonic welding, epoxy sealing, or heat sealing.