flyboy1963

flyboy1963

Well Known Member
just love my new Odyssey PC925, slipped in right were my old concorde was and has twice the crank. ( mounted on it's side, which is clearly allowed!)
After an hour flight, luckily I was changing the oil, and saw the battery lid had curved in the heat, and several of the little plastic vent caps had popped off. No leakage evident.
The dealer says only gas could come out the vents, and that it should be fine.

any ideas, experts, opinions?

I plan to make a solid aluminum cover to keep the lid flat and in place.

photo here;
https://picasaweb.google.com/lh/photo/vOjW7T8qWgfHtXwxku2P9T7C9Vwf5meZdG6VyXNtkIY?feat=directlink
 
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My experience with AGM (acid glass mat) batteries is that once they have vented like yours did, they are pretty much done. Yes they will work for a little longer, but you have lost a significant amount of electrolyte out of the battery and it is now on a death spiral that can include high temeperatures as it fails. The condition is brought about due to operation in a high temperature environment, which it looks like you have in this mounting location. As the battery is operating and being recharged in the high temp environment, it develops internal pressure, vents electrolyte, then the next cycle the temps go higher internally, it vents again, and so-on until failure. Traditional flooded batteries do the same, but they contain more electrolyte to begin with, so they not only have more to give, but they can absorb more heat as well and in many cases you can add water to them if the water level goes down. Odyssey also offers, at least in the PC680, a metal jacket version for these applications that can withstand higher temps, I am assuming because they put the metal jacket on and then put on higher pressure vents, so the battery doesn't lose the electrolyte.

Bottom line for me would be, if it were a car I would continue to run it and monitor. In an airplane, though, I would replace it.

Tim
 
Tim, I believe it is "absorbed" not acid in AGM.

I also thought of overcharging as a possibility, and possibily just simple heat.
 
I've heard it referred to (by the experts/maunfacturers) as "absorbed", "acid", and "advanced", so take your pick. I choose to call it acid to call attention to the fact that it is not really a different kind of battery than a standard flooded lead-acid, it is just packaged differently. Really I usually just call 'em AGM's.

Tim
 
From Wikipedia

A VRLA battery (valve-regulated lead?acid battery) more commonly known as a sealed battery is a lead?acid rechargeable battery. Because of their construction, VRLA batteries do not require regular addition of water to the cells, and vent less gas than flooded lead-acid batteries.[1] The reduced venting is an advantage since they can be used in confined or poorly ventilated spaces.[2] But sealing cells and preventing access to the electrolyte also has several considerable disadvantages as discussed below.
VRLA batteries are commonly further classified as:
  • Absorbed glass mat (AGM) battery
  • Gel battery ("gel cell")
An absorbed glass mat battery has the electrolyte absorbed in a fiber-glass mat separator. A gel cell has the electrolyte mixed with silica dust to form an immobilized gel.
While these batteries are often colloquially called sealed lead?acid batteries, they always include a safety pressure relief valve. As opposed to vented (also called flooded) batteries, a VRLA cannot spill its electrolyte if it is inverted. Because AGM VRLA batteries use much less electrolyte (battery acid) than traditional lead?acid batteries, they are sometimes called an "acid-starved" design.
The name "valve regulated" does not wholly describe the technology. These are really "recombinant" batteries, which means that the oxygen evolved at the positive plates will largely recombine with the hydrogen ready to evolve on the negative plates, creating water and preventing water loss.[1] The valve is a safety feature in case the rate of hydrogen evolution becomes dangerously high. In flooded cells, the gases escape before they can recombine, so water must be periodically added.
 
MINE DID THE SAME!!!!!!

flyboy1963 said:
just love my new Odyssey PC925, slipped in right were my old concorde was and has twice the crank. ( mounted on it's side, which is clearly allowed!)
After an hour flight, luckily I was changing the oil, and saw the battery lid had curved in the heat, and several of the little plastic vent caps had popped off. No leakage evident.
The dealer says only gas could come out the vents, and that it should be fine.

any ideas, experts, opinions?

I plan to make a solid aluminum cover to keep the lid flat and in place.

photo here;
https://picasaweb.google.com/lh/photo/vOjW7T8qWgfHtXwxku2P9T7C9Vwf5meZdG6VyXNtkIY?feat=directlink
Click to expand...
....Mine did exactly the same thing, same battery, mounted exactly the same way, with worse result as it became necessary to replace it after less than one year. Looking at the picture you posted it is exactly like mine looked. As expensive as these batteries are you would think they would give years of service. I wish these manufacturers would stand behind their products like we do instead of looking for an escape route so they can pass off responsibility. I will let everyone know how this comes out with the warranty issue as soon as they get back to me. Regards, Allan...:(
 
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