Battery Life
Kevin asks: Hello, I think my computer backup for the POS server is fried again. I came in on Tuesday with it screaching and red light flashing. Is it possible that the batteries are dead again? I\’ve already replaced them once before in the last two years.
Some helpful information BatteryWholesale.com. follows:
Information about UPS and Sealed Lead Acid Batteries
There are four major factors that affect UPS battery life (both sealed and flooded cells):
- Ambient temperature
- Battery chemistry
- Cycling
- Maintenance and service
Ambient Temperature
The rated output capacity of a battery is based on an ambient temperature of 25C (77F). It is important to realize that any variation from this operating temperature can alter the performance of the battery, and shorten its expected life. High temperature reduces the battery life greatly.
A good rule of thumb when determining battery life in relation to temperature is that for every 8.3C (15F) average annual temperature above 25C (77F), the life of the battery is reduced by 50 percent.
UPS Battery Capacity
UPS battery capacity is determined by the battery’s ability to convert chemical energy into electrical current at a specified rate for a specified amount of time.
UPS Battery Chemistry
No UPS battery will last forever– even one that experiences minimal use. This is because UPS batteries are electro-chemical devices whose ability to store and deliver power slowly decreases over time. So, even if you follow all the guidelines for proper storage temperature and maintenance, you still must replace them after a certain period of time.
Cycling
During a utility power failure (severe brownout or blackout conditions), the UPS operates on battery power. Once utility power is restored, the battery is recharged for future use. This entire “loop” is considered a discharge cycle.
At installation the battery is at 100 percent of rated capacity. Each discharge and subsequent recharge reduces the relative capacity of the battery by a small percentage. The length of the discharge cycle will determine the reduction in battery capacity.
The “loaf of bread” analogy is most often used to illustrate the relationship between cycling and battery life. A loaf of bread can either be cut into many thin slices or a few thicker slices. Similarly, a UPS battery can provide power over a large number of short cycles, or fewer cycles of longer duration.
Maintenance and Service
The final factor to consider is the maintenance and service of the batteries and the UPS. The gradual decrease in battery life can be monitored and evaluated through voltage checks, load testing and retorquing connections, as part of a periodic maintenance program.
Without regular maintenance and service checks, your UPS battery may experience:
- Heat-generating resistance at the terminals
- Improper loading
- Reduced protection
- Premature failure
With proper maintenance and service, the end of battery life can be estimated and replacements scheduled without any interruption or loss of backup power.