Substation Batteries 3

[musicguy1800]

The utility company I work for has several old lead-calcium substation batteries that are badly in need of replacement. I am doing some research to determine if there is another kind of battery that will provide a longer life and less maintenance. The manufacturer claimed that these batteries would last 10 years, but it was only three or four years before we started having problems. I have chosen to stick with wet-cell batteries for now, since using dry cells would require a change in our standards and practices.
One type of battery I am looking into is lead-selenium. Anyone familiar with this type of battery and its pros/cons? I have been told that there may be some environmental concerns. Also, any other type of wet cell (and manufacturer) that has proven to function well in your substation applications?

 

[alehman]

My experience closely matches easnj's.

 

[chiefwvfc]

Do any of you use or believe in on-line monitoring of substation batteries? I have heard many pros and cons but feel that it is worth the cost to know that all cells are in good condition when an outage occurs.

 

[GerH]

Our experience is the sealed type lead acid batteries typically failed in 3-5 years. The traditional cell with see-though casing seems to be good for up towards 15 years.

For the past 7 years or so we have used a gas re-combination filter ( Hoppecke Aquagen) on these vented cells and this has so far give zero top-up requirement and negligible corrosion around the connectors.

I know of Ni-Cad and Plante cells that I installed over 25 years ago still working as day one but obviously much more expensive.

 

[jbartos]

Suggestion: Operation and maintenance cost should not be overlooked. Visit

http://www.ieee-kc.org/library/battery/maint.htm

for Battery Maintenance aspects

http://www.eastpenn-powerbattery.com/eastpenn-vrla.html

for IEEE Battery Standards

http://www.gnb.com/stationary/stat-absxl.html

for 20 year life expectancy batteries
etc. for more info

 

[easnj]

I have seen banks with big bucks install fixed IMP battery monitoring at a high cost on their ups battery system. As I have 60 sites with > 5000 cells the cost prevents us from doing it. However if you have the money to monitor it do it. Being proactive rather than reactive in battery maintenance prevents the outage.

 

[alehman]

Most manufactureres have a range of product line in VRLA batteries. Liberty 1000 is one of the higher quality "10 year" VRLA in my mind. The longer life "20 year" VRLA usually use "AGM" for absorbed glass mesh electrlyte. C&D's Liberty 2000 series is an AGM type and warrantied for 20 years, and I would expect 7 to 10 years before seeing significant numbers of cell failures with that type. A good point for comparison between manufacturers is thickness of the positive plates, or more simply you can compare weight per amp-hour at the same rate (makers of less expensive batteries will argue that this is not valid).

 

[jbartos]

Suggestion: It is good to see a battery short circuit transient to get some idea about the battery internal resistance varying in very short time, e.g. millisecond range, to be able to design proper bracing in dc switchboards, and DC switches short circuit current ratings. Many DC disconnects are limited to about 20000ADC short circuit current level. The battery short circuit current transient may easily exceed 20000ADC level.

 

[musicguy1800]

Our Liberty 1000's are most commonly used in small substations that are primarily distribution substations. These small subs usually have a 10' x 12' panelhouse that contains all the relays and communication equipment, as well as a small office space. This is where our VRLA's reside. Obviously, we have to be careful about what we put in there as far as emissions are concerned. The panelhouses have heating / AC and the batteries are meticulously maintained...you would think the Liberty 1000's would last forever in those conditions, but we have started seeing problems after 4 or 5 years of service.
The vast majority of the batteries are LS 12-100's which are rated at an 8-hr capacity of 100 AH to 10.5 volts. Anything similar out there electrically that isn't a VRLA, will last longer, and won't cause ventilation concerns?

 

[busbar]

Don't the 'flame arresters' commonly fitted on flooded jars have any effect on battery location?

 

[jbartos]

Suggestion: Often, the battery rooms are furnished with two fans to provide a sufficient redundancy in the rooms ventilation.