I have a couple of Archon diving lights, a D33 that I’ve had for a few years and use 3no. 26650s to produce close to 3000lm from its 3 cree LEDs.
I recently purchased the same manufacturers WY08 primarily because I thought it used the same size batteries but uses 2no to produce close to 4000lm from its 4 cree LEDs but with a warmer light.
I have been away on a diving holiday and because of weight restrictions I only took the newer torch but took some of the older 26650s. When these were fitted that torch would not work and upon closer inspection found the new batteries were almost 70mm long. I gather these have protection fitted accounting for the extra length.
My question is: Is it possible to fit something to the older shorter batteries to allow them to be used in the newer torch?
Of course the torch has low voltage battery protection, it probably has some sort of low battery warning like “under 6.7V mandatory high to medium” the LD-29 driver has. An “underwater blackout” is probably undesired, isn't it?
Well, as I was saying, if you say the torch requires long batteries this is nonsensical to me. Anyway, if this is so probably the best thing would be to attach a longer bypassed tail and/or driver/head spring, but of course, it'd probably be much more convenient to contact Archon and ask them WTF?
Archon were the first people I asked, their reply was yes the WY08 batteries are longer as the include the protection. What I need (as one answer above) is how to fit the shorter 26650s from the older torch - I have the 2 longer ones that came with the WY08, but I also have a further 8 of the shorter ones which I would like to use in the WY08
Some people use small Nd magnets on the (+) nipple, but I personally don’t like that idea. Too easy for them to shift if dropped, potentially short out things inside the light.
Well, it is obvious now: the torch driver doesn't implements low voltage battery protection. This means you can over-discharge unprotected batteries with it.
Each board increases the esr (equivalent series resistance) of the battery pack by a tad above the combined RDS(ON) of the onboard MOSFETS, or about ≈15mΩ for a couple 8205As. Not a problem for up to the rated board current.
Either this, or buy rewrapper protected batteries.
Of course, I'd blatantly speak with Archon about this. I believe this is a poor design choice. Does the flashlight has any kind of voltage/charge gauge? If not, be ready for underwater blackouts. :facepalm:
