3AA to 2D holder melted

[Barrie]

got a few of the cheap KD holders which i have modded with copper and a few drops of solder all seamed to be ok until last night i was using my 2D mag with the AA-to-Ds
it was tail standing as i was working on the pluming under the kitchen sink
after 15 to 20 Min's i heard a crack and was hit with the rubber switch cover which had blown off
i picked up the light and burned my hand so using a towel i picked i up went out side once open i had to shake it like crazy to get the batteries out
it was raining and the batterers were hissing and steaming as the rain fell on them i let them cool for a while on inspection the holders have completely melted and the plastic covering is melted off 3 of the batteries
out of curiosity i put the batteries in my charger it indicated 3 of the batts were bad cells and 3 were OK i binned the bad cells but not sure that i trust the other 3 any advice wellcome think i will save up for some better quality holders

 

[Black Rose]

Wow, you were lucky, especially since there was enough pressure inside the light to pop the switch cover off.

Did you mod the holder to be parallel or was it still in the serial configuration (3.6v per holder)?

What kind of batteries were they?

Were the 3 bad batteries from the same holder?
If they were, then the other 3 should be OK I would think.

If the bad cells came from both holders, then I really don't know.

 

[Mr Happy]

It sounds like a short circuit developed. It's a bit odd though because normally the light would go dim if that happened.

 

[Marduke]

There is a reason those holders are NOT recommended for high current use. This is just one of many cases of them melting or worse when someone tries to cheap out on decent holders.

 

[Barrie]

i was not trying to go the cheap route they were the the only ones i could find at the time and the mod was followed from a post on here
please point me in the direction of better quality holders if you know where i can get theme at a reasonable price
getting burnt and lights going:poof: are not what i was trying to achieve
what are these holders suitable for:thinking: other than throwing in the bin

 

[Mr Happy]

I have a bunch of those KD holders and they are fine if you stay within their limitations. Essentially stick with low wattage bulbs like ordinary Mag bulbs and don't try to use them for hotwires.

If you attempt to mod them, be very careful not to allow accidental shorts either within the holder or against the metal wall of the light.

Bear in mind that even very expensive and well regarded battery holders have suffered from short circuit battery meltdown events. This is an area where cost is no guarantee of safety.

 

[rizky_p]

Yeah it happened to me once, but different situation. The switch cover actually poped-out by the pressure that the batteries produced.

I was building a 12 cells 3 wide 4 high Sanyo 2700 pack for my Penta Cree mag, the inner tube is enlarged(bored) for previous project so no anodizing inside to prevent short circuit. Over time the rough milling actually scrub the battery wrap and its basically an accident waiting to happened, stupid me!!. I know how hot your tube must be, man it was like a hundred watts of power dumped in seconds. None of my 12 cells survived but lesson learnt.

 

[Barrie]

would it be better and safer to use li-ion D size than AAs in holders :thinking:

 

[Mr Happy]

Although you had an unlucky incident, I don't think there is any particular problem with AA's in holders. Is it possible you did something bad to them when you modified them?

 

[Barrie]

Hi Mr happy thank you to yourself and the others for the input

i would like to stay with the AAs in holders for ease and availability of a common cell
i also realise Li-ion come with there own dangers and require special chargers and extra care for safety
i have seen the five-mega holder-charger which would appear to be a lot more suitable for my requirements
i am running a terralux m300 in 2D mag with the KD holders which has been OK so-far no problems atoll i was running a 6v in-can bulb when my light went in to meltdown
i would like to try building a ROP in the near future and know realize that these holders are probably not suitable
do you or any one else who may Read this post have any knowledge or experience of the five-mega holders though a lot more expensive i would rather pay the extra than hurt someone

 

[rizky_p]

would it be better and safer to use li-ion D size than AAs in holders :thinking:

true, but i am a little bit intimidated by big size lithium battery. Even a 18650 sized lithium still make me nervous :crazy:

 

[linterno]

Is it possible you did something bad to them when you modified them?

+1.

I guess you short circuited the batteries, those got to hot and melted the holder.

I am using those holders in a 2D mag mod pulling 1.7 amps from the batteries without any issue to date.