Battery life

How long should a 12V lead acid battery last?
 
I have a UPS backing up my HTPC.  I replaced the 12V 7.2 AH battery in October 2016 and it is utterly dead again.   That seems rather a short life to me.  We never had an extended outage so the battery backup only kicked in a few times for a few minutes each time.
 
Did I get a bum battery?
 
Craig

An SLA battery should last 3-5 years under normal use. A number of things can shorten the life of the battery, including temperature, depth of discharge, and the charging method and voltage.  One thing to check would be the voltage that the UPS is delivering to the battery when the battery is fully charged.  It should be between 13.5 to 13.8V for optimal battery life. 
 
Another factor that could result in a short battery life is the age of the battery when you first installed it.   SLA batteries need to be kept charged and shouldn't sit on the shelf for too long a time before being put into service.  You want a new battery that was manufactured within the last 6 months.  A year old battery is pushing it.  So it's best to buy a battery from a seller that has good inventory turn over.
 
I've had good experiences with Power Sonic batteries.  I purchased them on eBay from ecommelectronics.
 
If you're using 7.2Ah  1270 style batteries, you can also substitute 1280 or 1290 batteries.  They are the same physical size and will give you greater capacity.

Here too utilizing Power Sonic batteries for my OmniPro 2 (and sub panel) with no issues.
 
I have read about some folks switching to a newer style battery that is not the same.  It last longer and is a bit over $100 each. 

I second what RAL said about checking the charging voltage of the UPS. I have had experiences with generators on old cars overcharging (charging at too high a voltage) shortening battery life noticeably.
 
Mike.

Thanks!  I can't see anything on the battery that indicates the manufacturing date.  Between the terminals, there is a code, "FY11CFZ".  Pretty sure I metered this when I got it and it was slightly above the rated voltage.
 
 
I checked some more.  I bought the UPS in early 2008 and had to replace the battery in late 2009.  That battery lasted until 2016 and the latest one failed in 2018.  So one gave a good long life and two have been pretty short.  
 
Given that the UPS circuitry is 10 years old, would it be better to buy an new unit rather than put another battery in it?
 
Craig

pvrfan said:

Thanks!  I can't see anything on the battery that indicates the manufacturing date.  Between the terminals, there is a code, "FY11CFZ".  Pretty sure I metered this when I got it and it was slightly above the rated voltage.
 
 
I checked some more.  I bought the UPS in early 2008 and had to replace the battery in late 2009.  That battery lasted until 2016 and the latest one failed in 2018.  So one gave a good long life and two have been pretty short.  
 
Given that the UPS circuitry is 10 years old, would it be better to buy an new unit rather than put another battery in it?
 
Craig

Click to expand...

 
 
Some of the manufacturers make their date codes pretty cryptic.  And unfortunately, there is no industry standard for the codes.
 
I don't see a reason to replace the UPS simply because of age.  I have a couple that are well over 10 years old and they still work fine.
 
I would check the charging voltage to the battery.  While the battery is charging, you might see something as high as 14.5V.  But after it is fully charged, it should be in the 13.5 to 13.8V range.  If the voltages look ok, I would say the UPS is good.