NiMH Meltdown Mystery

[jayflash]

$20 worth of fairly new Duracell Precharged AA cells were somehow discharged in my Surge and two of them in one compartment split their jackets, vented, spewed electrolyte, partially melted and deformed the battery carrier.

The Surge hangs where I see it frequently, every day and had freshly charged cells installed on 5/30/08 used a few minutes that day and the next with no problem and full brightness. On 6/2/08 I turned the light on only to experience a sickening feeling, knowing the dim beam meant trouble. The switch lever was fully off and beyond the detent which securely keeps the switch off. Had the light somehow turned on, I or my family should have seen it, unless gremlins turned it on over night.

All the cells had been drained with two below one volt and two which were side by side had vented and slightly melted that part of the carrier. I could not find any electrical fault, such as a faulty switch or carrier short. Unless the fault cleared itself, I'm mystified.

The fault had to be common to both, paralleled battery sides. Temporary partial switch fault allowing current through the lamp without actually lighting it?

What would I explain to Princeton Tec or Duracell? Thank you for any help.

 

[half-watt]

do you have an inquisitive lil' brother (or friends of a lil' bro) around who might have played with it until it started going dim and then turned it off and put it back? that might be a good place to start the questioning! lock the place down, no one in, and no one out until you get to the bottom of this mystery!

 

[SilverFox]

Hello Jayflash,

Bummer...

The evidence points toward a shorted battery holder. I would take it up with Princeton Tec and see what they have to say.

Tom

 

[jayflash]

No, 0.5 Watt, no "helping hands".

Yes, Tom, that's the only thing I can think of considering the heat that developed. I haven't found any shorts, now, however. It's an old Surge, without the foam cushioning under the contacts. PT already replaced the carrier for my newer Surge, which developed intermittent contacts.

I know this is a dinosaur, but it fits the large 2D leather flashlight holder in my electrician's tool pouch and I like the size and switch lever on this light. With NiMH cells it puts out a nice and affordable incan beam with good flood from the Write Right film.

Anything of this size and output and maybe lighter? Plastic is fine, too.

 

[half-watt]

not an incan, but Coleman has a new, inexpensive 2D cell powered 55lumen Cree flashlight. burns for a long time (haven't tested this aspect yet) - Coleman claims something like 40h.
very large spill area to the beam pattern.

if this is of interest, be sure to enter the shopping area through the "Family Store" link on the main Coleman webpage. the password is "FAMILY" (w/o the dbl-quotes). significant discounts on many (most???) items is the norm.

 

[jayflash]

Thanks much half-watt. The light need not be an incan so I'll check out the Coleman.