Uneven drain in SSC P7 mag mod?

[Zeva]

Hello so turned on my mag P7 mod and it was abnormally dim so i took out the batteries and tested them two read around 1.49 the last read .1 volts.. What would cause this? the batteries were put into the flash light new... i thought at first that i left the light on by accident but that wouldnt explain the uneven drain would it? thanks for the help

Forgot to mention i have barley used the flashlight so the batteries should all be around the 1.49 mark

 

[Ronstar]

A few questions: Are you using 2 AA batts? Alkaline, Lithium, or rechargeable? Are the batts the same type/mfr?
If alkaline, most have a little more voltage than 1.49 when new; are these more than a year old? Does the P7 driver have a memory function and who makes it? The answers will help us figure out what's wrong :thinking:

Ronstar

 

[Hack On Wheels]

Hello so turned on my mag P7 mod and it was abnormally dim so i took out the batteries and tested them two read around 1.49 the last read .1 volts.. What would cause this? the batteries were put into the flash light new... i thought at first that i left the light on by accident but that wouldnt explain the uneven drain would it? thanks for the help

Forgot to mention i have barley used the flashlight so the batteries should all be around the 1.49 mark

I'm going to assume that these were freshly charged NiMH cells, is that correct? It would help if you gave us more information on the batteries and your setup; it'll be easier to pinpoint why this happened.

 

[Zeva]

Wow cant believe i left that part out! but they are duracell alkaline batteries this is the first time its happened but still weird... The Led was bought off DX C bin? i believe

 

[Battery Guy]

Wow cant believe i left that part out! but they are duracell alkaline batteries this is the first time its happened but still weird... The Led was bought off DX C bin? i believe

Assuming that you did not accidentally put one of the cells in backwards (yeah, that would never happen to me :whistle:), the only possibility is that you got a bad alkaline cell that was already self-discharged before you put it into the light. While rare, you will occasionally get an alkaline cell that has an internal short circuit that causes it to slowly discharge on shelf or in your flashlight.

You are fortunate that the cell did not leak all over the inside of your flashlight.

It is good practice to check the OCV of alkaline cells prior to use. A fresh-out-of-the-package alkaline should read ~1.65V. Anything less than 1.60V should not be used.

Cheers,
Battery Guy

 

[Hack On Wheels]

Wow cant believe i left that part out! but they are duracell alkaline batteries this is the first time its happened but still weird... The Led was bought off DX C bin? i believe

Alkaline batteries, so not rechargeables? Did you use them much? Do you use a driver or is it direct drive?

I'm not the most knowledgeable when it comes to batteries, but it sounds to me like that battery was probably a dud from the beginning. (So my 2nd and 3rd questions really aren't important...)

 

[Zeva]

ohh ya direct drive... they have been barley used... I think i remember testing them when they were newish and they all said 1.65 or so.. but i m not completely sure... so will this battery start leaking randomly? xDD i tried the flash light maybe last week and it was still very bright but i looked at the led while on today and wasnt even blinded :(

 

[AnAppleSnail]

ohh ya direct drive... they have been barley used... I think i remember testing them when they were newish and they all said 1.65 or so.. but i m not completely sure... so will this battery start leaking randomly? xDD i tried the flash light maybe last week and it was still very bright but i looked at the led while on today and wasnt even blinded :(

Alkaline cells can't be trusted. Some brands are better than others, but they sometimes leak sitting in storage, in original packaging, in watertight containers, in flashlights, and under heavy load. They leak new, old, and it's always bad for your electronics.

 

[Battery Guy]

ohh ya direct drive... they have been barley used... I think i remember testing them when they were newish and they all said 1.65 or so.. but i m not completely sure... so will this battery start leaking randomly? xDD i tried the flash light maybe last week and it was still very bright but i looked at the led while on today and wasnt even blinded :(

Well, if they all started at 1.65V then I am somewhat puzzled. :thinking: It is possible that the cell developed an internal short during use, then self-discharged while the flashlight was not being used. This is a rare failure mode, but it does happen from time to time.

I would not worry about this. It is almost certainly a problem with the Duracell battery and not with your flashlight. If the same problem comes up with a different set of batteries in the same flashlight, then I think we need to spend more time figuring this out. Otherwise, ditch the alkalines and put some lithium AA batteries in that light.

Cheers,
Battery Guy

 

[Zeva]

Lithium D cells? :P Okay ill go see if i can get a good deal on some NIMH D :) thanks for the help! if this happens again ill come back panicking!

 

[Battery Guy]

Lithium D cells? :P Okay ill go see if i can get a good deal on some NIMH D :) thanks for the help! if this happens again ill come back panicking!

Doah!!! :ohgeez: I missed that! My bad, I was thinking that they were AA cells. So sorry!

Seriously though, you must have got a bad Duracell alkaline cell. Like I said, this is a rare failure mode, and I would not expect that you would see it again.

Cheers,
Battery Guy

 

[Zeva]

K thanks for the help!