FAQ: What is the expected life of my APC UPS battery?

[BillP]

Most APC batteries should last three to five years. Below are some guidelines to ensure optimum life expectancy:

***Some APC Back UPS models may have a shorter battery life expectancy. Please reference the user's manual of your APC Back UPS to determine the exact battery life expectancy.

1. Make sure that you keep your APC UPS in a cool, dry location with plenty of ventilation. Ideally, the temperature where your UPS is kept should not exceed 75° F (24° C). Also, for ventilation purposes, leave roughly one to two inches on each side for proper airflow.

2. Only perform runtime calibrations on your UPS one or two times a year, if necessary. Some of our customers want to check their systems to verify that their runtime is sufficient. However, consistently performing these calibrations can significantly decrease the life expectancy of your APC battery.

3. Do not store APC batteries for extended periods of time. New batteries can be stored for 6 to 12 months. After this period, the battery should be used or it will lose a great deal of its charge. It is not advisable to store batteries that have already been in use.

4. Do not exceed 80 percent of a UPS unit’s rated capacity due to the reduction in run time. When you increase your load, your runtime lessens. In the event of a power failure, a UPS loaded to full capacity will drain and discharge it’s battery quickly and will lessen the life expectancy.

[Anonymous user]

II'd like to add a few things from what I know and experience.

WildWatt wrote:
Most APC batteries should last three to five years. Below are some guidelines to ensure optimum life expectancy:

***Some APC Back UPS models may have a shorter battery life expectancy. Please reference the user's manual of your APC Back UPS to determine the exact battery life expectancy.

1. Make sure that you keep your APC UPS in a cool, dry location with plenty of ventilation. Ideally, the temperature where your UPS is kept should not exceed 75° F (24° C). Also, for ventilation purposes, leave roughly one to two inches on each side for proper airflow.

2. Only perform runtime calibrations on your UPS one or two times a year, if necessary. Some of our customers want to check their systems to verify that their runtime is sufficient. However, consistently performing these calibrations can significantly decrease the life expectancy of your APC battery.

3. Do not store APC batteries for extended periods of time. New batteries can be stored for 6 to 12 months. After this period, the battery should be used or it will lose a great deal of its charge. It is not advisable to store batteries that have already been in use.

SLA batteries can be stored for a few years with little loss of performance if they're topped off every 3-6 months. As long as they're properly topped off, they will hardly degrade. You need to charge them before they fall below 60% capacity or they will permanently degrade in capacity. About 12mo at 25C, less at higher temp.
http://img262.imageshack.us/img262/8952/slastoragedb6.png
From 12v 17Ah CSB battery engineering datasheet (two of them makes an RBC7)

Batteries in service will degrade from electrode corrosion from being placed on 13.8v/pack float voltage and accelerated deterioration from higher temperature inside the cabinet.

SLA in extended storage degrade from sulfation.

Best life from temporarily decommissioned UPS can be obtained from leaving them disconnected from power, but allowed to charge on an appliance timer in storage area for an hour or so a week to automatically replenish the battery.

4. Do not exceed 80 percent of a UPS unit’s rated capacity due to the reduction in run time. When you increase your load, your runtime lessens. In the event of a power failure, a UPS loaded to full capacity will drain and discharge it’s battery quickly and will lessen the life expectancy.

I believe that heavy loads don't actually reduce the actual degradation speed of battery, but battery simply simply loses their maximum load sustaining ability as they increase in their internal impedance. There's also a trend in consumer grade UPS to mate a larger inverter with a smaller battery.

I recommend around 50% load or less for newer consumer grade UPS. A 450VA UPS from 1992, BK450 came with a 12Ah battery, but these days, you'll find 750VA units with a smaller battery, so the battery is actually pushed harder.

You can't change the rate of actual degradation, but if you don't push the battery pack hard and you leave more than enough runtime, you increase the service life until the performance reaches below expectation, for example if you need 200W for 5minute, getting a UPS that can supply 200W for 10 minutes will remain serviceable until it can only maintain 5 minutes where a unit that can only do 6 minutes with new batteries will fall below 5 minutes mark far sooner.

[BillP · Accepted solution]

I just bought my BE325R Surge Protector/Battery about a year ago. Tonight, when I got home the alarm was sounding on it. I turned it off and then on again. It hasn't gone off since. Does this mean I need to replace the battery? Shouldn't it have lasted longer than this?

[TheNotoriousKMP_apc]

Chances are it's indicating a battery disconnect. I would double and triple check the battery connection on this UPS.