View Full Version : 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?
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?
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
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
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)
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.
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
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 (http://en.wikipedia.org/wiki/VRLA_battery) has some decent images of that.
Steven Sigley
15-03-2012, 02:31
note: DO NOT OPEN UP YOUR BATTERIES EVER. Thanks for your time ::safety::
now for the lazy:
http://upload.wikimedia.org/wikipedia/commons/thumb/2/2f/AGM_inside.jpg/800px-AGM_inside.jpg
Also these look roughly like what we use if i had to guess
http://www.elec-intro.com/EX/05-15-02/deka-cross-section.jpg
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
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
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.
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
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::
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.
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.
On the top of the batteries there is a small plastic strip that hides the vents, as show by a bad battery.
Vents (http://i.imgur.com/WH5p0.jpg)
Al Skierkiewicz
16-03-2012, 07:48
Bill,
I don't think that label caused the problem, it simply was the evidence of the vent.
Bill,
I don't think that label caused the problem, it simply was the evidence of the vent.
Agreed. Unfortunately we will never know for sure. Another mentor immediately disposed of the two questionable batteries at a recycle center and they are now gone. I now think there was may have been nothing wrong with them, but it a minor loss to insure safety.
Hopefully this will encourage us to review our battery practices and safety procedures. It appears that not everyone on the team that was handling batteries had the same knowledge or followed the same process. If nothing else we can use this experience to help the students learn more about proper battery safety, care, and at least where we keep the battery spill kit.
Al Skierkiewicz
16-03-2012, 11:52
Even with training, team members sometimes forget. Here is a short list of battery do's and don'ts.
1. Never lift the battery by the wires. Guaranteed to break the terminal inside the battery.
2. Always use two hands, the batteries are heavy and have no good grasping points.
3. Don't charge when hot, i.e. right after a match. Wait at least 15 minutes.
4. If you run you battery down in just one match, reevaluate your mechanical design. A good rule of thumb is several minutes or at least two matches. Best tested during practice at your build space.
5. Insulate all exposed metal/wire/terminals. The battery is capable of currents that can weld.
6. Insist that only those students or adults that know how the battery is designed to be mounted in the robot actually place the battery in the robot.
7. Do not use the alligator clips on your battery charger to connect to the Anderson Power Products connector. The clips will scratch and deform the contacts which lead to high resistance and high heat. Yes Virginia, high enough to melt/fuse the connectors. There is no good way to insulate the clips for this operation.
8. Do not drop the battery. More batteries have been killed by dropping on a corner or breaking loose internal parts.
9. Test your batteries at least once or twice a season with a good battery checker. West Mountain Radio CBA II or III is a good way to tell battery status without trying to draw huge currents. The Cross the Road Battery Beak, battery checker is also a quick way to check battery health prior to a match.
10. Do not depend on a DMM/DVM to give you any usable data. It will simply tell you terminal voltage without telling you if the battery can actually supply current.
For this year, please insure that your battery will not bounce around inside your robot and many teams, (WildStang included) are adding some padding to prevent serious G-shocks to the case and internals.
2. Always use two hands, the batteries are heavy and have no good grasping points.
And don't take this to mean "If you have big enough hands you can use one". I've almost/slightly pulled something in my thumb multiple times carrying batteries 1-handed using the little ledges on the top ::safety::
perlgerl
18-03-2012, 11:02
If the leak was from the terminal seals, this is a manufacturing defect and should be communicated to the manufacturer. Please post the manufacturer (ie Genesis or MK battery) and the manufacturing date code (ie YYMMDD + extra letters) which is stamped in the top of the battery case.
This year in our kit of parts, the Kinetic Knights Team 781, received a Genesis battery manufactured July 17 2010 (batch code E100717FB). We have not had any leaks. We inspected our terminal seals and saw no defects. Some pictures of a disassembled MK Battery are posted on our website (http://www.team781.com/images/stories/781/batteries.pdf) (3 MB pdf).
Diesel Torch
18-03-2012, 11:17
Last year we lost 7 batteries because of leakage... This year we upgraded to new chargers and we haven't lost a single one... :cool:
Last year we lost 7 batteries because of leakage... This year we upgraded to new chargers and we haven't lost a single one... :cool:
Did you switch to a completely different type of charger? If so, what were the old ones, and what did you switch to.
Also, Al Skierkiewicz I really like your list of battery rules. In particular
#6 Insist that only those students or adults that know how the battery is designed to be mounted in the robot actually place the battery in the robot.
I would consider extending this a bit and think our team perhaps should have a formal battery handling certification. I too often here a coach, driver, programmer, or mentor yell, "Anyone!, we need a fresh battery now." Somehow replacing a battery has become some time critical priority, and anyone is considered qualified to replace one. We are trying to get away from that, and insure that proper battery handling procedures are followed. But we seem to be fighting a lot of inertia.
Seth Mallory
18-03-2012, 12:24
Our batteries have a harness made from old seatbelts. When you have installed the cables the battery cannot come out and you have a two inch wide cloth carrying handle. It makes also very easy to remove from the robot. You do have to design the battery box larger to fit the harness. A fellow ham in my ARES/RACES group made the harness originally so 60+ year operators could carry the same size batteries safety
Tristan Lall
18-03-2012, 20:14
I'll be cutting that one apart* to analyze that failure later this season.
I would love to know how that's done (properly).
I would love to know how that's done (properly).
Arm-length rubber gloves through a Lexan panel into a ventilated hood?
Diesel Torch
18-03-2012, 20:37
Did you switch to a completely different type of charger? If so, what were the old ones, and what did you switch to.
The old ones were the HPX-60's.
The new ones I'm not sure about, but they are similar to the 3-way one on andymark.com but it only chargers one.
I would love to know how that's done (properly).
Arm-length rubber gloves through a Lexan panel into a ventilated hood?
With a ROBOT! ::safety::
otherguy
19-03-2012, 02:03
2168 received a leaky battery this year.
while our battery never leaked (we stopped using it), our battery had come with 1 of the lead terminals weak to the point where i could move it back and forth. That was this year.
Al Skierkiewicz
19-03-2012, 08:02
Davis,
High on the list of reasons is someone carrying the battery by the wires. The terminal is only soldered in place under the red or black sealant. This allows the same battery to be supplied with various terminations under different part numbers.
yarden.saa
19-03-2012, 10:56
We got a battery in the KoP that was shorting...
It wasn't leaking and we couldn't find any reason.
Al Skierkiewicz
19-03-2012, 11:38
yarden,
Shorting?
I was definately the only person to handle the battery. Also I noticed it before I had the chance to put any wires on it.
@Yarden- did it just make random disconnectings? That is what the bad terminal battery did (tested it because FIRST refused to replace it).
As an example of the disconnecting, it would get everything booted, but the moment I pressed enable, we lost communication.
Al Skierkiewicz
20-03-2012, 08:04
Davis,
Was there any damage in the packaging?
Informative discussion. For the last two years we have mounted the battery upright in the robotic with sturdy support around it. Because I don't tug on Superman's head. (Most days.)
Al Skierkiewicz
20-03-2012, 09:16
Frank,
It's don't tug on Superman's Cape. Long story on how I know this.
Frank,
It's don't tug on Superman's Cape. Long story on how I know this.
http://www.youtube.com/watch?v=YQrTGE4wwwA
marccenter
20-03-2012, 11:21
Last year we lost 7 batteries because of leakage... This year we upgraded to new chargers and we haven't lost a single one... :cool:
This is true; but not necessarily conclusive. We checked the suspected chargers last year for Voltage and Current draw and concluded they were in specification. We checked them at the Troy district event where we were having the issues with leaky batteries. Using new chargers with new batteries this year is inconclusive because we changed two variables, the chargers and the batteries. We would have to be using the old chargers with new batteries in order to be conclusive.
Although not 100% conclusive, the sensible conclusion seems to point to the new batteries received at the Troy district event (may have been damaged in shipment or defective from the factory). What makes it less than 100% conclusive are other potentially unknown factors (charger may have been faulty in an intermittent way - happened when we were not testing?).
Captaindan
20-03-2012, 13:10
The mks have never leaked for us though the black tops we have had problems with. When they start leaking take them to a local scrapyard and use the money to buy new mks. Handle with chemical proof gloves to avoid chemical burns :)
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