Gel-cell (VRLA) battery reliability 2

[wde3477]

Well, I first posted this question in the 'Battery Engineering' forum, but no response after a week, so I figured I'd try another forum containing more members.

Our insurance inspector voiced concerns over our recent installation of VRLA batteries, and suggested a capacity test even though the batteries are less than one year old. This is our first VRLA set on a larger system (2000 Amp-hour) - capacity tests are currently scheduled for our 'normal' Lead-Acid sets every five years. The research I did prior to specifying VRLA did not reveal any serious problems with this style battery - assuming proper maintenance and operation is done - and the pricing and delivery made them especially attractive. I would like to hear of any negative experiences or known problems with this type of battery that would support our inspector's concerns.

 

[Lewish]

I would suggest that you contact someone at a large telephone company. The ones I know of, Verizon (formerly GTE) and Bell are using VRLA exclusively in their remote terminals, and are slowing converting out their big wet bath lead acids in their main substations. The right person at one these companies could probably answer you question quite thoroughly.

 

[busbar]

Not intending to be overly callous to voiced concerns of your insurance “inspector” but can you tell if are his direction is based in formally reviewed or anecdotal information?

Possible applicable info at: thread237-10473 thread238-21287 thread238-11254

Much less the journals, or IEEE Stationary Battery Standards Collection, or
IEEE Std 1184-1994 Guide for the Selection and Sizing of Batteries for Uninterruptible Power Systems
IEEE Std 1187-1996 Recommended Practice for Installation Design and Installation of Valve-Regulated Lead-Acid Storage Batteries for Stationary Applications
IEEE Std 1188-1996 Recommended Practice for Maintenance, Testing, and Replacement of Valve-Regulated Lead-Acid (VRLA) Batteries for Stationary Applications
IEEE Std 1189-1996 Guide for Selection of Valve-Regulated Lead-Acid (VRLA) Batteries for Stationary Applications

http://standards.ieee.org/reading/ieee/std_public/description/powergen/1375-1998_desc.html

http://standards.ieee.org/reading/ieee/std_public/description/powergen/450-1995_desc.html

http://standards.ieee.org/reading/ieee/std_public/description/powergen/484-1996_desc.html

http://www.cdpowercom.com/

or

http://www.gnb.com

Besides comms, the rail industry seems to have a lot of {however small} stationary dc in extreme environments. Then there’s notable shops like Albér, too.

While not intending to suggest biting the hand that may someday feed you, they may be thought of a most pessimistically manic aspect of business ventures.

However, there currently seems to be some very serious designs of VRLA “rackage” out there.

 

[Lewish]

Excellent reply busbar! You deserve a star.

 

[peebee]

Battery technology sucks. Unfortunately, it is about the best we have (whether rotary is better is debateable). In general, distrust your batteries.

VRLA's have a typical life of 5 to 8 years (regardless of warranty claims). Testing every 5 years seems like too long an interval. Every year sounds about right. Every 6 mos or quarter would not be excessive in a critical application.

Wet cells have a typical life of 15 to 20 years. 5 year testing is reasonable, although if you are really worried about it I'd test them every year, too.

Unfortunately, there is a tradeoff, as each discharge test will also decrease the life of your battery.

Keep in mind one bad jar can kill your whole string. Even if your system has 3 or 4 parallelled strings, you might lose 25 or 50% of your capacity after a year due to 1 or 2 failed jars, and not even realize it unless you either do a load test or check the impedance of each jar.