Battery Explosion 5

[bertramh]

Hi I am having a problem with some Power brand batteries, they are located in a cabinet supplying UPS feed but they are blowing their covers and this is happening only in UPS with Power battery. Does anyone have an explaination or have the experience of seeing this happen.

 

[mouli11]

hi mr bertramh
Is the battery enclosure well ventilated ,may be if required the enclosure can be kept open and performance observed. As well as the charging current may be reduced and the change in temperature may be verified.
Mouli11

 

[DaveMarz]

Depending on the age of your UPS it should be monitoring the batteries to prevent a runaway. How old is the UPS and batteries??

 

[chiefwvfc]

ScottyUK, check out

http://www.on-lineinc.com

for a reliable battery monitor if you are looking for a monitor in place of the Vanner unit.

 

[bertramh]

Davemarz the UPS is five years old and it suppose to be monitoring the batteries but the UPS shows one hundred percent capacity but the batteries keeps exploding and I have since removed three strings from the system and it's still showing 100% capacity.

 

[jbartos]

Suggestion: If a battery is defective, it may explode without detecting anything on a very elaborate and expensive battery monitor, except the one that would monitor the temperature of each battery cell.

 

[alehman]

This is a follow-up to my earlier post in this thread -

Our UPS batteries failed last weekend. This is a 12kW UPS with a string of (20) 12V VRLA batteries (Power Battery). They have been tested at six month intervals with a brief load application, internal resistance and voltage at six month intervals. The last test was about 5 months ago and they were fine. Tuesday morning the UPS showed a battery alarm. The battery voltage was varying between 200 and 290 volts every few seconds(!).

The service company came and tested the batteries and found about half of the 20 jars showed infinite internal impedance. They could not find any problem with the UPS. I don't know if there was an extended outage because the event log overflowed with battery warnings after about ten minutes. The computers it supplies never shut down though. We obtained a set of temporary replacement batteries and installed them. They seem to function normally.

Fortunately none of the battery jars exploded. They are about 3 years old. It doesn't seem reasonable that half the batteries would go from good to open in five months. The manufacturer has not yet determined if they will provide any compensation via their ten year pro-rated warranty.

 

[RRaghunath]

VRLA batteries may not be expected to have a life of more than 5years.
The health of the batteries can be monitored by measuring the specific gravity of acid in case of vented type battery cells.
However, with VRLA batteries, the battery impedance monitoring (commercial devices are available)is the only available method apart from physical appearance like distortion, cell voltage on no-load / on load etc, which are not known to be all that reliable methods.
The manufacturing defect also can be an issue such as the cells gas more than they should while on charge thus causing excessive internal pressure build-up/explosion. The problem could also be with the battery charger settings.
Thus, the subject needs to be looked in to from different angles and I tried to present few of my thoughts.
Trust you find them useful.

 

[GOTWW]

Do, they by the chance,wet cells with the catallyist tops, that recombine the H and 02 back to H20?, These heat up during equallization. A long shot, but these are sold after market.

 

[alehman]

Thanks for the ideas. There was no obvious sign of pressure build-up (explosion, swelling, etc). The mfg. data does not mention any type of catalytic system. It does say the cells normally operate at "a small internal pressure". Any ideas on how I may tell by appearance if the catalyst exists?

The charger was set for 272 volts which is 2.27 volts per cell - within the mfg. recommended float voltage range.

They have offered me a 12% discount on a new string for the pro-rated warranty. I am looking at other manufacturers.

 

[RRaghunath]

2.27volts per cell for float charge seems on high side.

If my memory serves right, it should be between 2.23 to 2.25V/cell (at this voltage cells should not require any periodic equalising charge).

Normal vented type cells (not low maintenance variety) are maintained at 2.16 to 2.20 V/cell to limit the water loss.

 

[alehman]

Power Battery recommends float voltage from 2.27 to 2.30 vpc (with a small temperature adjustment factor). I think this is fairly typical of high s.g. VRLA batteries. I am most confused as to why we would suddenly see such a large number go bad, esp. without a total discharge.

 

[light1]

Nature of the malfunction suggests that batteries may be a defective series from the manufacturer. Batteries from another manufacturer could be tried.

 

[upsengineer]

power batteries are not the best in the world. i recived a set from the manufacture to in stall and found four passing there saftey seals. This is a concern as it will give rise to a high impedance value of the battery. Did any of the vent vales show signs of passing. what was the ambient temperature within the room where that batteries were situated as a 5 degree rise in teperature will reduve the life expectancy by half.

 

[bertramh]

Gentlemen it's the same findings I had from the start of this thread, the batteries just go bad in batches. Since then I have switched battery manufacture on my two large ups systems. My conclusion is there is some defect with this brand of batteries since the supplier was unable to give me a reasonable explaination. I have a question for all of you, we are about to purchase a 100KVA ups and we are including a battery monitoring system in the tender, what is some of the systems available and do you know of any site I can take a look?

 

[controlnovice]

Bertramh,

Our company just received a call from Eaton (Powerware) and they are replacing our UPS batteries for free due to batteries not in spec. We have a 25kVA system. They said some of their customers experienced problems, so they are changing all of these, even if the customer has not had problems. The batteries in question have a case that is too thin and are cracking.

I would recommend calling Powerware. I spoke with Allen at 919-870-3217. Make sure you have the UPS model number.

Good luck.

 

[busbar]

One monitor producer in Alber.

http://www.alber.com/Products.htm#CBM