Battery Explosion
Battery Explosion
(OP)
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.






RE: Battery Explosion
RE: Battery Explosion
Has overcharging been ruled out?
RE: Battery Explosion
If so, that could be an indication of a bad electrical connection within the battery unit.
RE: Battery Explosion
If so, they may be the wrong type of construction for a trickle charge, low load application, such as I would expect on a UPS. "Car" type batterys are made for high load and relatively high recharge rates and will sulphate up and distort plates to the point of shorting out and causing ignition of gasses if used on long term "standby" applications. There are batterys made more suitable than others for this type of application. A good manufacturer would advise on this.
RE: Battery Explosion
Busbar, with the failure of the battery and the low cells voltage of some the charging current has increased to compensate for this low voltage.
Alehman, No other UPS units in our network with power batteries blow their tops.
Jre, the batteries are of VRLA type, and to you all can you tell me one of the better manufacturer for batteries of this nature.
RE: Battery Explosion
Good luck!
RE: Battery Explosion
RE: Battery Explosion
My question actually was - Do the same batteries repeated blow their tops? In other words, do you replace the tops and see them pop off again? Or do you replace those units right away. Are the battery cases fractured when this happens?
Low voltage? How low? The charging current should not increase due to low voltage if the UPS rectifiers are behaving corretly. You should get your UPS's checked out. What manufacturer are the UPS's?
Power battery makes VRLA and flooded cell types for many applications. As jre suggested, a consult with them would be worthwhile also.
RE: Battery Explosion
RE: Battery Explosion
RE: Battery Explosion
jbhartos, The batteries with the blown top are hot.
RE: Battery Explosion
Technician liked to stick notes/papers on the side of a power cabinet with magnets. Long story short, one of his new SmCo magnets (held lots more papers) was placed just right so that a CT in a power supply was biased by the DC field and the output went overcurrent (control feedback lost due to the poartial dc saturation) with no one the wiser and no shutdown. Similar possibility in your case could cause overcharging on just that one UPS and lead to the hot/exploding batteries. No magnets policy on the side of the PS 'fixed' the problem.
Submitted that happening as part of a lessons learned paper to IEEE Ind. Application Journal in '95, reviewer said journal never published 'hypothetical' cases!!
BTW, tried to 'blow up' a car battery when younger, only way to get it to do so was to charge at 100 A for 5 minutes with covers off and continuous ignition spark going - personal conclusion was it takes a real specific set of circumstances to blow a battery. Did know of some GTE techs in 80s killed by exploding Li Thional Chloride batteries.
RE: Battery Explosion
It was gassing well with the filler caps screwed on and I generated a nice spark by shorting the thing with a piece of rubber coated automotive wire. (I liked the red hot wire & smoke you see).
Except that on this occasion, the cell nearest to the positive terminal popped and cracked the battery casing.
Result: acid all over the concrete floor which started bubbling away generating CO2.
Quite exciting really.
No real damage to me or the floor, and the battery was scrap anyway.
But I was very lucky.
rgds
Zeit.
RE: Battery Explosion
See http://www.powerbattery.com/acro-file/PQ2000.pdf
My company has an 18kVA Powerware UPS with a cabinet full of VRLA Power batteries also. None have blown up yet. We have a twice yearly testing program - I guess I'll renew that contract...
RE: Battery Explosion
RE: Battery Explosion
It's also worthwhile to do a full discharge test annually (with individual cell voltage recording) for critical systems.
RE: Battery Explosion
RE: Battery Explosion
The cost of these systems initially can be expensive, but the reduction in maintenance costs usually pays for the system especially in catastrophic situations.
You can find a system at www.on-lineinc.com.
RE: Battery Explosion
RE: Battery Explosion
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
RE: Battery Explosion
RE: Battery Explosion
RE: Battery Explosion
RE: Battery Explosion
RE: Battery Explosion
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.
RE: Battery Explosion
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.
RE: Battery Explosion
RE: Battery Explosion
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.
RE: Battery Explosion
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.
RE: Battery Explosion
RE: Battery Explosion
RE: Battery Explosion
RE: Battery Explosion
RE: Battery Explosion
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.
RE: Battery Explosion
One monitor producer in Alber. www.alber.com/Products.htm#CBM