What causes an SLA Battery case to crack?

There are several reasons why the casing of Sealed Lead Acid batteries may crack:

• dropping
• collision
• overcharging when vents are not functioning correctly

Dropping

A SLA battery case is of plastic construction and is designed to hold the acid and plates in place rather than have any shock resistant capabilities. If the unit is dropped, even when held a few inches above a hard surface, this can be enough for the heavy weight of the unit to crack the casing.

Collision

Damage to the casing due to collision is most common in a warehouse or storage situation where another object collides with the battery. This could be anything from a fork lift truck to another unit falling on top creating enough pressure to crack the casing.

Overcharging and vent not functioning

If a SLA battery is charged to fast for it’s specification excess gases build up within the unit. However they are fitted with a valve (and hence this battery type is sometimes referred to as Valve Regulated Lead-Acid) to allow the gas to escape.

Should the valve fail and not open the pressure caused by the gas can be enough to crack the case, or in extreme situations, cause it to explode.

What do do with a cracked SLA Battery?

Although the unit may not leak acid (the liquid is held in a glass mat or gel) immediately there is a risk that the battery’s life-cycle and capabilities will be reduced. There is also the possibility, especially with gel based batteries, that acid will eventually start seeping out and cause corrosion to the materials in the surrounding areas.

As such sealed lead acid batteries with cracked cases should always be replaced immediately. For more information, help or assistance call BatteryGuy toll free on 800-572-1975.