Nothing can be done to prevent a battery from eventually reaching its end-of-service life. However, avoiding the following mistakes can help ensure a maximum lifespan.
- Poor storage of unused batteries– Even as a battery sits unused, its lifetime begins to decrease. That’s because lead-acid batteries automatically discharge small amounts of energy.
To prolong a battery’s storage life, we recommend you charge it every three to four months of storage. If you don’t, you could see a permanent loss of capacity in as little as six months. You can also prolong your unused battery’s storage life by storing it at a temperature of 50°F (10°C) or less.
- High ambient temperature– The rated capacity of every battery is based on an ambient temperature of 77°F (25°C). Any variation, but especially increased temperature, can affect performance and lifespan. As a general rule, for every 15°F above the recommended ambient temperature, the expected life of the battery is reduced by 50 percent. Routine maintenance checks can help detect thermal hotspots and verify proper ventilation.
- Over-cycling– After a UPS operates on battery power during a power failure, the battery recharges for future use, an event called the discharge cycle. When a battery is installed, it is at 100 percent of its rated capacity. However, each discharge and subsequent recharge slightly reduces the capacity of the battery.
- Improper float voltage– Every battery manufacturer will specify the charging voltage ranges for their own cell design. If a battery is consistently charged outside of these parameters, it can cause significant damage.
Undercharging or low voltage can cause sulfate crystals to form on the battery plates. These crystals will eventually harden and reduce the available capacity of the battery over time.
Overcharging with a float voltage that is too high can cause excessive hydrogen and oxygen gases and can lead to internal dryout that, once accelerated, can cause thermal runaway – resulting in failure or even fire and explosion.
- Incorrect battery application– UPS batteries are made specifically for UPSs, just as other batteries are made specifically for their respective appliances. UPS batteries are built to deliver extremely high rates of energy for a short time, generally up to 15 minutes.
Conversely, other batteries, such as telecom and switch gear batteries, are designed to run for longer periods of time, typically between four and eight hours. If a user runs a telecom application with a UPS battery, it will force the battery to run for much longer than its intended purpose. This could cause the battery’s plates to overheat and fail.