Double your lumens:Zebra H501 on 14500 BUG

[Linger]

Possible direct drive bug producing 180lumens.

Hello,
This bug rocks. First emerged last night while I was modding my first Quark, I just wanted a bit of task light so had zebra on lower, got to work, and unexpectedly Zebra went ultrabright. Took me some time to isolate the bug, always thinking this is how superstitions develop: unrelated events incorrectly associated. A longer time to develop a simple reproducible path. Why are the easy things hard to find?
(I use the short 14500s, w/o protection circuits to preserve the spring)

Method:
Take one Zebralight H501 fed on 14500
Unscrew the tail-cap (locked out), no power to the driver
Screw in tail-cap
With constant press and HOLD: turn it on, first to low, keep hold of the button and mode changes to medium
Wait 5 seconds

Result:
The output changes to uber-high, by my eye 180 lumens as twice normal high of 90 lumens
Using the switch changes back to regular modes, low / mid / high.

Discussion:
I suspect it is direct drive. Important to say, the light does not appear to be getting warm though I haven't dared leave it longer then a few minutes (I've got an important canoe trip coming up in 4 days and don't want to risk losing my Zebralight).
The light appears to have challenges with 14500's: outside of this bug, when the light is turned to high, the output wavers occasionally.

Now if I could find a moonlight bug, this H501 would be almost perfect (needs neutral tint). The ultrahigh output is superbly useful, exactly what I want.

 

[Linger]

No one else eh? Strange. Seeing as it occures after a delay I feel its more of a coding bug vs. assembly error specific to my unit.
I used the error high mode last night for a longer time while checking on some gear I'd set up in the backyard to test in the pending storm. The Zebra does get warm (as expected) but less so then any of my small high-output lights (quark, mc-e modded Ultrafiire mcu-c7).
Maybe I"ll contact Zebralights after my trip.
Best,
L

 

[Foxx510]

Mine just cycles through the modes on a 14500 as normal when I hold the button down. I can't put the tailcap on though as the protected 14500 I have is too long.

 

[Linger]

Right.
Foxx, lets start from you first putting the 14500 in. The first time you press the botton to turn it on, HOLD it until it's cycled from low to medium. Then release the button (before it cycles to High, this is very important).
Wait 5 seconds and see if the light changes modes on its own.
Anything?

 

[skyfire]

just tried my h501w with aw14500. but no dice. i have the older UI version. with low/med/high and double tap for strobe.

 

[Linger]

Thanx, weirdness.

 

[Foxx510]

Holy crap! This time flames came out! Just kidding, no luck with mine either. You must have the secret special experimental version ;-)

 

[Linger]

Thanx for trying. I first thought I'd just found an easter egg. Now I'm stumped.
I'll do pics of the uber-high after the trip, or maybe a video though I'd have to figure that whole deal out. I'll update thread title when / if I'm successful.

 

[hyperloop]

thanks

that would be cool if it could double the lumens. I've put a 14500 in my H501 but nothing really special in terms of output

 

[Henk_Lu]

If I put a 14500 AW in my H501w, I'm not able to screw on the tailcap completely anymore. The light goes on, but has only one mode, high as it seems, it just flickers a little dimmer and back if I press the switch, no luck though...

 

[ryanandty]

Hi! I am unsure of whether you found an easter egg, but I was playing with the twist cap on my new h501w with updated UI, trying to locate a position that would allow for momentary usage while squeezing the top and bottom, and swore up and down it produced at a higher level both times I got it to work (on simple rayovac alkalines!). I haven't been able to do it consistently though, and since I didn't buy it for that, I don't think I'd like to fry it trying. you know,

 

[kosPap]

Update!

I tested this (old) headlamp with CR14505 batteries (3V lithium primaries)

intially i was getting about 100 lumens and a draw of 0.42A.
But you know how hhard it is to keep the headlamp standing on its switch while putting DMM leads on the battery and body rim.
So after some more tries i started getting ...
205 lumens (my testing) and a 1.2A draw!

Seems i got the bug1
now back to more tries to turn the feature of...
Thanks Linger...