What causes alkalines to leak?

its explained very well in the link above, i would remove them from any flashlight or device not in constant use

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.

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.

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

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. :~

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

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

Most smoke detectors use 9v. They’re a true “battery” of 6 alkalines. Maybe higher standards? A leaky cell wouldn’t show any signs immediately because of the housing which also offers some protection to the device. Our TV remote always gets new cells before old ones start there destruction.

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

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.