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  #1  
Old 01-29-2012, 08:00 PM
Earl Snake-Hips Tucker Earl Snake-Hips Tucker is online now
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So why was my AA battery buzzing?

I had been noticing an intermittent buzzing sound from my DVR remote. I figured it was about to die, so I took the two AA batteries out. To my surprise, the buzzing sound continued for a moment--but not from the remote! It was very certainly one of my AA batteries, which continued buzzing for a minute or two.

And, just to head the questions in case they should arise: It was most definitely *not* the remote. It most definitely *was* the battery, and it did continue for a minute or two after removal.
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  #2  
Old 01-29-2012, 08:03 PM
TriPolar TriPolar is offline
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Was it a rechargeable battery?
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Old 01-29-2012, 08:09 PM
Earl Snake-Hips Tucker Earl Snake-Hips Tucker is online now
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Don't think so. One of these. My box even says "use by 2013," like this one.
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Old 01-29-2012, 08:32 PM
jz78817 jz78817 is offline
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was the battery warm? alkaline batteries have a paste-type electrolyte, and if it starts leaking or seeping out of the seal it can sound like buzzing.
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Old 01-29-2012, 08:32 PM
TriPolar TriPolar is offline
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Nope, not recharageable, it's an alkaline. Got no idea.

ETA: Looks like jz78817 has an idea.

Last edited by TriPolar; 01-29-2012 at 08:33 PM..
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  #6  
Old 01-29-2012, 09:07 PM
Earl Snake-Hips Tucker Earl Snake-Hips Tucker is online now
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Quote:
Originally Posted by jz78817 View Post
was the battery warm? alkaline batteries have a paste-type electrolyte, and if it starts leaking or seeping out of the seal it can sound like buzzing.
Don't recall that. Maybe so. I had been using it a lot prior to the buzzing, so the battery did get a workout.
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  #7  
Old 01-30-2012, 01:18 PM
Al Bundy Al Bundy is offline
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great post

I do a lot of work with batteries. I had not heard them buzz when leaking. You must have exquisite hearing. It would be interesting to know what the voltage on those batteries was. A battery tends to leak more when discharged.

PS. I have exploded lithium batteries when overcharging. Alkaline cells are much more docile. I suppose any leak that could make a noise might be able to squirt out from a tiny crevasse that could spray in your eyes so be extra careful.
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Old 01-30-2012, 02:24 PM
engineer_comp_geek engineer_comp_geek is offline
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Since I doubt that your remote can draw enough current to make the electrolyte boil, I suspect that there was a manufacturing defect in that battery. Maybe the case was pinched at some point allowing the positive and negative sides to touch at one small contact point, or maybe the anode inside was misaligned. In either case (or if there is some similar type of damage or defect) you end up with essentially a short circuit at a small contact point, which causes a lot of current to flow and heat to be generated. The electrolyte boils, and pressure builds up inside the battery. Usually at the bottom of the battery, under the metal plate, there's an expansion seal. This seal intentionally has a weak area in it. If pressure builds up, it will bust through this seal and vent outside the battery, often making a buzzing or hissing noise when it does so. This is a good thing, since it means pressure can't build up to the point where the battery just explodes.

If there is a defect around the edge of the case, the same sort of thing can happen with the pressure being released at the defect instead of breaking through the seal. This is what jz78817 is describing. Had the battery been dropped at some point? Was there a kink in the case somewhere?

Charging an alkaline battery can cause this sort of thing to happen too. You can unintentionally charge a battery and damage it if you have one dead battery in series with one or more good live batteries. You should always use the same type and brand of batteries together, preferably out of the same package, so that they all go dead pretty much simultaneously. Since alkaline batteries aren't rechargeable you don't really care if you damage an already dead battery (it's dead, you're just going to throw it out anyway) but if the electrolyte leaks out of the damaged battery it can cause quite a bit of damage to the device it is in. You wouldn't want to buy a new DVR remote just because one of the batteries went dead.

You actually can recharge alkaline batteries to some degree, but you really shouldn't. They don't take a full charge and there is a high risk of the battery swelling, leaking, and damaging your equipment.
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Old 01-30-2012, 02:37 PM
jz78817 jz78817 is offline
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Quote:
Usually at the bottom of the battery, under the metal plate, there's an expansion seal. This seal intentionally has a weak area in it. If pressure builds up, it will bust through this seal and vent outside the battery, often making a buzzing or hissing noise when it does so. This is a good thing, since it means pressure can't build up to the point where the battery just explodes.
this is what I saw, but in fairness it was my own fault. I was going to make receiver packs for R/C vehicles and practiced on alkaline AAs. 'course, alkaline and NiMH cells have radically different construction so it should have been no surprise when the alkaline vented on me.

Quote:
You actually can recharge alkaline batteries to some degree, but you really shouldn't. They don't take a full charge and there is a high risk of the battery swelling, leaking, and damaging your equipment.
IME modern smart chargers (even the $10 things you get at the supermarket) will refuse to even try to charge alkalines.
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Old 01-30-2012, 07:12 PM
Earl Snake-Hips Tucker Earl Snake-Hips Tucker is online now
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Update: It has been sitting out cold for 24 hours, then all of a sudden sgarted uzzing for about a minute,
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Old 01-30-2012, 07:52 PM
engineer_comp_geek engineer_comp_geek is offline
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Quote:
Originally Posted by jz78817 View Post
IME modern smart chargers (even the $10 things you get at the supermarket) will refuse to even try to charge alkalines.
I haven't tried it with a modern charger. I know the cheap older ones (back when the only rechargeables you could get were Ni-Cads) would at least try to charge the battery. I've also seen at least one flashlight designed to hold a rechargeable batteries that would charge any kind of battery placed inside of it. Someone put alkalines in it, and they swelled up and leaked goo all over the inside, ruining the flashlight (it also had a radio in it - it was one of those emergency kind of things that you keep charged until you need it).

Quote:
Originally Posted by Earl Snake-Hips Tucker View Post
Update: It has been sitting out cold for 24 hours, then all of a sudden sgarted uzzing for about a minute,
Did it get warm? Did any goo leak out of it?
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  #12  
Old 01-30-2012, 07:56 PM
Earl Snake-Hips Tucker Earl Snake-Hips Tucker is online now
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Nope and nope. Outside high temp today 65, and inside was probably not much different. Eh. . . I hope it's not a booby trap.
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