/ Alpkit Gamma shorting out?

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TobyA on 16 Nov 2012
I've 'got a lotta love' for Alpkit( http://lightfromthenorth.blogspot.fi/2012/06/alpkit-in-operation-kayak-touring-in.html ), so this isn't meant as a moan. I've had my Gamma a good few years now and it has worked flawlessly over quite a lot of use. It spent one winter tied to my bike helmet, rain, sleet, snow, -20. No problems. So I have without doubt had my money's worth from it, but it went wrong in a moderately spectacular way this week and I wonder if anyone else has seen similar.

I lent it to my son for his cubs outside meet this week, he came home reporting it had "broken" (kids, don't you just luv 'em and their ability to break all your stuff?). It had new batteries in it so I knew that wasn't the issue. On taking the batteries out (just normal IKEA alkalines) on one there is a noticeable black scorch mark and all three the yellow plastic around the batteries had shrunk exposing some of the metal. I've not seen this before, but can only imagine that it was sudden heat to make the plastic shrivel like that? So a short circuit? There is also some kind of residue or discolouration inside the battery box - again I don't think it was there before. So it seems like something exciting happened in there.

The connections seem damaged but not totally blown now, as it still works sometimes but with a tendency to turn itself off and on in an unhelpful manner. I know lots of people have broken their Gammas physically, but has anyone else seen this? I was wondering if the batteries could have been the problem or something in the battery case that made it short?
Monk - on 16 Nov 2012
In reply to TobyA:

I've had batteries do something similar before - the plastic jackets shrank. The weirdest thing, was that these batteries weren't in a device at the time this happened - they were sat on a bed in a hut while I was out for 3 days. They may have got quite cold (sub zero) but they were not exposed to any heat or any obvious method of shorting them. I had no idea what caused it. I returned them to Duracell, who replaced them with no quibble. Is it possible that this is due to faulty batteries?
jkarran - on 16 Nov 2012
In reply to TobyA:

Sounds like one or more of the batteries has supplied too much current and overheated. The plastic film shrinks with heat and the residue is possibly from one or more of the batteries venting. Cylindrical cells can short internally or at the end caps especially if if abused but it sounds like the fault is more likely in your torch. The other possibility is if there are 3 cells your young lad put one in back to front, I'm guessing it's a modern LED lamp with a switching supply which will still be able to draw a lot of current (more than usual) from that set up overcharging and overheating the reversed cell. The two correct ones would also be heavily loaded and run warm. That wouldn't explain the propensity for turning itself off now though.
Phil79 - on 16 Nov 2012
In reply to TobyA:

Coincidentally, my Gamma head torch went wrong about 2 weeks ago. It was about two years old and like you had been used through 2 winters strapped to my bike helmet, plus plenty of other general outdoor usage. The batteries ran out and when I replaced them, the switch on the rear LED was stuck on flashing mode.

I emailed Alpkit and they got me to sent it back via freepost. As usual very good customer service, they rang me up and told me there was a likely short circuit in the battery compartment, probably caused by water ingress and battery corrosion. They suggested that after use in heavy rain/wet weather, the batteries are removed and battery compartment left open over night to ensure its dry. They knocked 10% off a replacement, which I thought was a very nice gesture as they had no obligation to do so.
mattrm - on 16 Nov 2012
In reply to TobyA:

My gamma is a bit iffy as well, but for £12.50 it's hardly something I worry too much about. I think it's a dodgy connection around the actual light area, as it only seems to go when I adjust it.
TobyA on 16 Nov 2012
In reply to jkarran: I changed the batteries and it worked fine, and I also took them out when after it stopped working, so I'm certain they weren't in incorrectly. The residue could have been in there before, from older batteries that had leaked somehow? Can whatever that powdery stuff is (some sort of oxide I guess) that leaky batteries leave, lead to a short circuit? I guess it needs to be able to conduct?
Alpjay - on 22 Nov 2012
In reply to TobyA: Hey Toby,

Bit of a mystery, my personal experience with older torches has been after leaving batteries in for a long time without using them something similar has happened. Had you left the torch unused for a while? Sometimes it is just a cheaper brand of battery causes a problem if it leaks.

Drop us an e-mail and I can sort out getting it back to us to have a look at and hopefully repair or help out on a new one -

TobyA on 22 Nov 2012
In reply to Alpjay: Could well have been as you say Jay. I've been using the same IKEA batteries for years and not had problems with them before, but they are cheapish (why I buy them!) and I'm sure the same ones had been in there for a long time - long days means little need for torches in summer. As I said, it must be four years old now and has been used a lot, so I wasn't expecting it would last forever anyway, but sort of just interested to find out how it went wrong! Will email you.


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