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-   -   Who has had a leaky battery this year? (http://www.chiefdelphi.com/forums/showthread.php?t=104631)

tsaksa 14-03-2012 19:35

Who has had a leaky battery this year?
 
We had two batteries leak this year with no signs of mechanical damage. This was a small amount of acid appearing near the two rectangular indentations near the terminals on top of the battery. We do not think they were over charged, and we were using the standard single battery chargers sold by Andy-Mark.

I hear via rumor that at least a few other teams at our regional had at least one leaky battery this year as well. These were the first two leaky batteries our team ever had, and according to the safety folks I spoke with at regionals battery leaks have been fairly rare in the past few years. Hopefully we are not looking at a systemic problem or a bad lot of batteries, but I am curious to hear from other teams that may have had leaking batteries this year. If you did have a leak, did you notice the location or any other significant conditions?

dez250 14-03-2012 19:46

Re: Who has had a leaky battery this year?
 
Which orientation do you charge and use your batteries in (ever upside-down)?
Also have you noticed any bulging in the case or missing the top rectangular cover on either battery?
Also do you notice any movement or play in the terminal lugs on the batteries?

ENIAC 14-03-2012 20:25

Re: Who has had a leaky battery this year?
 
Our batteries are placed in the robot horizontally, but we did this in 2010 with no issues. This year, two batteries, one that was used in the robot and one that was just sitting on a table, showed up with staining beneath the tape holding on the label.

Al Skierkiewicz 14-03-2012 20:28

Re: Who has had a leaky battery this year?
 
T,
Are both batteries from this year? Had you run them in the robot during matches while on the bridge or going over the barrier? Do your students carry them by the wires? All of these can cause seal damage to the batteries.

Steven Sigley 14-03-2012 20:43

Re: Who has had a leaky battery this year?
 
Quote:

Originally Posted by ENIAC (Post 1144293)
Our batteries are placed in the robot horizontally, but we did this in 2010 with no issues. This year, two batteries, one that was used in the robot and one that was just sitting on a table, showed up with staining beneath the tape holding on the label.

I believe we cracked the glass on the inside of our batteries by playing with them laying horizontally in 2008 at the San Diego regional. No idea if problems like leakage could be related though. (I've never observed any leakage myself)

Ether 14-03-2012 23:26

Re: Who has had a leaky battery this year?
 
Quote:

Originally Posted by Steven Sigley (Post 1144307)
I believe we cracked the glass on the inside of our batteries

The "glass" is a fiberglass mat. Perhaps someone who has taken one apart could comment on how brittle it is and likely it would be to crack.



tsaksa 15-03-2012 00:52

Re: Who has had a leaky battery this year?
 
Quote:

Originally Posted by Ether (Post 1144426)
The "glass" is a fiberglass mat. Perhaps someone who has taken one apart could comment on how brittle it is and likely it would be to crack.



I believe the glass mat is not very brittle, but perhaps I can track more information down without needing to dissemble a battery. By a strange coincidence the battery separator material is actually made in our town.

PAR_WIG1350 15-03-2012 00:54

Re: Who has had a leaky battery this year?
 
Quote:

Originally Posted by Ether (Post 1144426)
The "glass" is a fiberglass mat. Perhaps someone who has taken one apart could comment on how brittle it is and likely it would be to crack.



Wikipedia has some decent images of that.

Steven Sigley 15-03-2012 02:31

Re: Who has had a leaky battery this year?
 
note: DO NOT OPEN UP YOUR BATTERIES EVER. Thanks for your time ::safety::

now for the lazy:



Also these look roughly like what we use if i had to guess


tsaksa 15-03-2012 12:39

Re: Who has had a leaky battery this year?
 
An important note. Both batteries were labeled with a large paper label and tape that covered the area marked (pressurized vent system). There was also very little liquid present, and it was only noticeable because there was paper and tape trapping it in the area we now know is a vent. There is at least some possibility that the batteries did not actually leak, but that it was just that the tape trapped and helped to condense normal venting gasses.

I will carefully look over the batteries later this week and see if this may be the case. One interesting fact is that the person responding to the leak commented that baking soda did not fizz when dumped on the battery. This along with the very limited amount of liquid suggests to me there is at least some chance that this is not a classic spill.

Don't worry, I will be careful. I just want to make sure that we know what happened. I suspect that we may at least want to have whoever labels batteries in the future be more careful not to accidentally cover the vent area.

marccenter 15-03-2012 13:07

Re: Who has had a leaky battery this year?
 
We had two batteries leak in 2011 - new ones from FIRST. We checked the chargers for current, voltage, etc? and was not able to determine the nature of the cause. We had FIRST personnel at the Troy district tournament last year working with us to help figure our the issue to no avail.

Speculation on my part is that the batteries may have been dropped in shipment.

Al Skierkiewicz 15-03-2012 17:35

Re: Who has had a leaky battery this year?
 
T,
A normal by-product of the charge and discharge cycle is water vapor due to heat genrated within the cell. The vents open to release this pressure in the form of vapor. Even though the manufacturer says the battery can be charged in any orientation, I recommend that the battery only be charged in the upright position. Any liquid at the vent will be forced out when the cell pressure exceeds the vent trip. That liquid then pushes out of the vent. Following the charge cycle this water then recombines in the cell. As a battery loses water, it's peak capability is also lost. In gel cells this is more of an issue as the gel then decreases to the point were the plates are not fully covered by electrolyte. With gel cells it is/was easy to pickup a battery and actually feel the weight loss compared to a newer battery.

tsaksa 15-03-2012 17:41

Re: Who has had a leaky battery this year?
 
Quote:

Originally Posted by Al Skierkiewicz (Post 1144683)
T,
A normal by-product of the charge and discharge cycle is water vapor due to heat genrated within the cell. The vents open to release this pressure in the form of vapor. Even though the manufacturer says the battery can be charged in any orientation, I recommend that the battery only be charged in the upright position. Any liquid at the vent will be forced out when the cell pressure exceeds the vent trip. That liquid then pushes out of the vent. Following the charge cycle this water then recombines in the cell. As a battery loses water, it's peak capability is also lost. In gel cells this is more of an issue as the gel then decreases to the point were the plates are not fully covered by electrolyte. With gel cells it is/was easy to pickup a battery and actually feel the weight loss compared to a newer battery.

Thanks.

I had a feeling the labeling was a tad excessive and the batteries may not have been really leaking. I will discuss this with the team and make a plan for how to proceed. Batteries remain one area where we need to exercise more diligence.

DonRotolo 15-03-2012 21:23

Re: Who has had a leaky battery this year?
 
OK Folks, after 25 years in the industry, I think I know a little about batteries, maybe. Search my posts to be sure.

We had a battery start leaking at the negative terminal this year, a 2011 battery. It was charged properly, handled properly, etc. Literally out of nowhere it started to leak.

I'll be cutting that one apart* to analyze that failure later this season. For now it is contained properly. More soon.

* I am a trained professional and have cut (literally) thousands of batteries apart in my career. I have seen people injured badly by flying highly-concentrated sulphuric acid and small chunks of lead while doing this. If there ever was a time to hear and obey this, it is now: Do not try this at home. ::ouch::

Bill_B 15-03-2012 23:01

Re: Who has had a leaky battery this year?
 
I just took a close look, in pretty good light, at one of the batteries looking for the vent(s) mentioned above. I'm presuming it/they is somewhere in the black "cap" on top, but I did not recognize anything obviously as a vent. It all looked pretty solid to me. I was wonder what part could be taped over to cause a problem.


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