Wikipedia
http://en.wikipedia.org/wiki/Alkaline_battery#Leaks

Edit: [note 1] in the second line reads, with a mouse hover
This alkali particularly attacks aluminium, a common material for flashlights, which can be damaged by leaking alkaline batteries.

I experience two times duracell leaked, one in storage and other inside Terralux 300.
almost unable to get the battery out as it sticked so persistently.

I’m not really sure why it leaked but maybe the expiration time has something to do. in my case it was coming close (about a year due). usually alkaline cell have 5 years storage time since production so I consider 1 year left is close already.

Bort wrote:

I’ve always wondered, also does airtightness have any effect on it?

Good thread question.

I have wondered the same. Having had at least a half dozen or more lights slightly damaged, or even destroyed by alkaline leaks, I am now freaking out. The few lights I still may run on an alkaline battery, I seem to try and check them every couple weeks. I am now afraid to run an alkaline in any of my decent lights of any kind.

What causes it? The constant high or low temps experienced for example in an automobile? The age of the cell? Multiple cell lights only?

I seem to never have a problem in a TV remote (or smoke detector) for some reason.

I have a 3D Maglite I’ve been trying unsuccessfully to open after the batteries leaked inside…

You can try pouring in some vinegar to help dissolve the mess.

Chloe wrote:

You can try pouring in some vinegar to help dissolve the mess.

Pour it in where? I cant get it open! I could drill a hole I guess.

The alkaline cell uses the shell — zinc metal — as part of the chemistry. It’s supposed to be thick enough it doesn’t get eaten away from the inside enough to leak — in single use. Ha. Haha. hahahahahhaaha

http://www.corrosionist.com/clean_alkaline_battery_corrosion.htm

I’d say it’s poor sealing right from the factory since most never have a problem under the exact same conditions. Capacitors leak too but that might be due to heat/pressure. I dunno, just guessing.

hank wrote:

The alkaline cell uses the shell — zinc metal — as part of the chemistry. It’s supposed to be thick enough it doesn’t get eaten away from the inside enough to leak — in single use. Ha. Haha. hahahahahhaaha

http://www.corrosionist.com/clean_alkaline_battery_corrosion.htm

I think the main problem is hydrogen gas build up rupturing the casing or damaging a seal.

spaceboy wrote:

Pour it in where? I cant get it open! I could drill a hole I guess.

Ahh, do you have a vice or something to wrench it open (you can put leather around it to help prevent scratches)? I used vinegar in my Fluke volt pen as two cells were corroded so much they were stuck inside. It works now after some cleaning and letting it dry out.

That stuff ate pieces of my Stanley 3 in 1 Tripod. All three lights had a crust holding the batteries tight. Fortunately, the metal parts were SS which cleaned up easily with a toothbrush and Liquid Wrench (it’s what I had). I put it back together with the residual oil left behind for good measure.

That’s good. There was a copper strip in my volt pen that needed cleaning with isopropyl alcohol. It really eats through aluminium though. Here’s my ruined Maglite:

The spring and nylon bulb holder were unaffected.

I stopped using Alkalines a few years ago. Now it’s just for the few devices where NiMh won’t work, and if I’m worried about someone throwing them away, like the kids. The emergency kits in the vehicles even have LSD or lithium primary batteries in them now.

I only use alkalines in devises that consume batteries quickly enough to change them out often. Thought that light would get used more. :~

lightme wrote:

I only use alkalines in devises that consume batteries quickly enough to change them out often.

I used to do that until I had a few leak and ruin my devices. Now those devices get Eneloops.

Chloe wrote:

That’s good. There was a copper strip in my volt pen that needed cleaning with isopropyl alcohol. It really eats through aluminium though. Here’s my ruined Maglite:The spring and nylon bulb holder were unaffected.

That is a really stark reminder that either extremes of the PH scale are always corrosive!

Backpacker Light wrote:

I seem to never have a problem in a TV remote (or smoke detector) for some reason.

lightme wrote:

That stuff ate pieces of my Stanley 3 in 1 Tripod. All three lights had a crust holding the batteries tight. Fortunately, the metal parts were SS which cleaned up easily with a toothbrush and Liquid Wrench (it’s what I had). I put it back together with the residual oil left behind for good measure.

Same thing happened to my Stanley 3 in 1 tripod. Bad design.

spaceboy wrote:

Chloe wrote:

You can try pouring in some vinegar to help dissolve the mess.

Pour it in where? I cant get it open! I could drill a hole I guess.

Unscrew the head. If it won't shift unscrew the bezel ring, remove the lens and reflector. If the bezel won't shift you are probably stuffed.

Don wrote:

spaceboy wrote:

Chloe wrote:

You can try pouring in some vinegar to help dissolve the mess.

Pour it in where? I cant get it open! I could drill a hole I guess.

 

Unscrew the head. If it won’t shift unscrew the bezel ring, remove the lens and reflector. If the bezel won’t shift you are probably stuffed.

I unscrewed the head and can see the plastic bulb holder thing. Does that unscrew?

spaceboy wrote:

Don wrote:

spaceboy wrote:

Chloe wrote:

You can try pouring in some vinegar to help dissolve the mess.

Pour it in where? I cant get it open! I could drill a hole I guess.

 

Unscrew the head. If it won't shift unscrew the bezel ring, remove the lens and reflector. If the bezel won't shift you are probably stuffed.

I unscrewed the head and can see the plastic bulb holder thing. Does that unscrew?

No - to remove the switch assembly you need to prise off the switch cover and insert a 5/64" hex key into the hole in the middle of the switch assembly and unscrew the pointy screw that cuts through the internal anodising to make contact with the aluminium body. I believe more recent Mags use a Torx screw which would be around TX5 or thereabouts - I've never seen one so don't know. Then there's a C ring retaining clip in front of the switch assembly that needs circlip pliers to release. Then you can pull out the switch assembly. Then have at it with vinegar/lemon juice whatever mild acid you have knocking around. It's best not to use stronger acids as the reaction with the strongly alkaline crap could be violent.

If the sun comes out from behind the rain and fog we have here just now, I'll do pics today.

Thanks. I’ll need to get some circlip pliers then.

A couple of fine nails or screws can be substituted. Or some strong tweezers.

You just need to pull the ends of the ring in enough to release it from the groove cut into the body.

Here's how to take out the switch the easy way.

Unfortunately this won't work with the cells stuck inside which is why we have to go in from the front.

Oops, my memory was at fault. A fine flatheaded screwdriver is what you want to shift the retaining ring - I'm sure the older ones needed circlip pliers but my memory may be at fault here.

In this pic you can see the retaining ring - it is the lighter coloured ring at the base of the bulb tower. I used this old pic as my cameras have gone into hiding so the pic of the ends where you can remove it was taken with a nasty phone cam of stupidly high resolution and equally stupidly high over-sharpening and noise.

You can see the notches in the ends of the ring here. They're at about 2-3 o'clock. Just get a small flathead screwdriver in there and lever it out of the groove. If it won't shift try washing it out with well hot water, dry it and shoot some WD40 in there then shake it out after a minute or two.

Good luck

Thanks for the tips. Had to get a 2mm allen key, got one today. Been trying for the last 20 minutes to release the circlip. Really difficult.

I read on another forum that the guy gave up on alkylines for remotes and things like that and just uses plain ol carbon ones. They might not last as long but they don’t leak. I’m going to try that.

Back in the day, I needed one of those teenytiny 12V batteries (A23) for my car’s remote. Rat Shack sold the C-Zn ones for 89¢ each, and they lasted for years.

Then, those were discontinued, and they only sold the hateful little alkaleak versions for almost 3bux a pop… which only lasted a year at best.

If anyone even made C-Zn AA/AAA cells anymore, I’d buy ‘em by the box for clocks, remotes, small instruments, etc.