Skilhunt h03 - light flashing off normal behavior?

I recently purchased a Skilhunt h03. During all of my recent use sessions I noticed that, in addition to the colored indicator light (built into the on/off button) flashing to let my know my battery was dying, the light itself began to flash off and on twice in a row, and then three times in a row every few seconds. Is this normal behavior? Is there any way to disable this behavior? It’s very distressing when the thing you’re working on goes dark every few seconds.

For background, I’m using a 18650 KeepPower 3600mAh Panasonic NCR18650G Protected Button Top in the Skilhunt h03.

The user manual refers only to the indicator light flashing, not the main led. But I’ve seen a different Skilhunt light, a DS10, do exactly as you describe. I’ll test my H03 with a depleted battery and see what happens.

Thank you, I appreciate your efforts and assistance.

Tested two specimens of H03 and both behaved as in the manual. So two flashes of the indicator every 10 seconds below 3.3V; three flashes every 10 sec below 3.0V, and complete shutoff at around 2.7V. No flashing of the main LED, although there is an undocumented progressive shutoff of the higher modes as the voltage drops when the protection operates.

I would find the behaviour you describe to be unacceptable, although in my use I almost always keep the cells above the LVP level.

I’m now wondering about my recollection of the behaviour of the DS10 that I reported. In the interest of Science, I’m discharging a cell to look at that.

I can’t thank you enough for addressing my question in such a systematic manner. I’ll have to get in touch with skilhunt as I find this unacceptable as well.

Since the light has Low voltage protection, you don’t need a protected cell. By using a protected cell, you are adding resistance and voltage sag. Try an unprotected cell, and your problem will probably go away.

Try Robert’s suggestion. The light’s LV warning should kick in well before the cell’s protection circuit, but maybe there is some interaction.

The next para is just for the record. It does not indicate anything useful about your H03.

The DS10 low-voltage behaviour is very different. I guess it has to deal with both 16340 Li-ions with a nominal voltage of 3.7V and CR123A single use cells at nominal 3.0V (and max around 3.3V when new). The LV indicator flashes from around 3.3V under load, and all modes but one are locked out. There is no LV shutoff at all. The LV warning is remembered when the light is turned off, but not if the light is reset by releasing the tail cap. However, at a slightly lower voltage everything works again after a reset. At very low voltages (under 2V maybe) the light does flash the main LED in sympathy with the indicator. But that voltage is so low that any protected cell would have shut off long ago.

I don’t own any unprotected cells as I don’t have the time to fully grasp their limitations. I’ve purchased protected cells thus far for my tn12, knockoff convoy c8, and Skilhunt so that I don’t have to worry about overdischarge.

This post seems to suggest that while protected cells are unnecessary for the Skilhunt, they should work fine. Reddit - Dive into anything

Thanks again

Protected cells do work fine. That’s what I normally have in mine. I used an unprotected (and dispensable) cell for the test above, though. Maybe just try another cell, preferably of a different make if you have one.

I just tried a KeepPower 3500mAh Panasonic protected cell in the light. After the battery was run down for a while, it began the same flashing behavior. Two blinks every two minutes.

The usual LV warning on the H03 starts with two quick flashes of the indicator behind the button, then a ten second pause, then two more flashes, and so on. It does appear that your light has a problem.

I suspect Skilhunt will tell you to go to the retailer, unless it came direct from their online store. I had a problem once with a light bought direct from them, which they replaced promptly even though it was a dirt-cheap sale item. Good luck.

I have the same issue with a H03R purchased from Aliexpress on Sept 19th 2019. Unfortunately I did not discover the issue until earlier this month so there is no relief from the retailer. It appears to be the same as yours, two flashes every two minutes, of the main LED once the battery gets at and below ~30% capacity. It makes the light essentially unusable for the role I purchased for.

Did you contact Skilhunt? I have not received a response from my email to them on November 8th.

No, I sent it back to the seller on eBay. They just received it. I might buy on amazon instead for easier returns in case I get another one with this “feature.”

Thanks for the update, I will most likely gift the light away for Christmas and just replace with another Zebralight. Undisclosed “updates” are the worst, but I suppose that’s what I get for buying from the lowest cost retailer.

Both my wife and I have H03s, and both main emitters flash when the battery is getting discharged.

Personally I don’t rate the red LED flashes to give a good estimate of life remaining

I have part of an explanation. It seems that Skilhunt have recently changed the way the indicator relates to the state of charge of the battery. The information on the current Skilhunt website includes the following:

_Low voltage indication & Power indicator
When the battery voltage drop down lower than 3.3V, indicator flash twice every 4 seconds. Battery voltage drop down to lower than 3V, indicator flash 3 times every 2 second.

Every time press the switch turn on, the side indicator will flash to display the battery power.

Power > 80%, the indicator flash 4 times,
Power > 50%, the indicator flash 3 times,
Power > 20%, the indicator flash 2 times,
Power < 20%, the indicator flash 1 times._

That is not how my light works. The interval between the bunches of warning flashes on my light is 10 seconds, not 4 or 2 seconds. Also mine does not flash to show the battery state when the light is switched on. In both of these ways, my light conforms to how it was advertised at the time and to the user manual that came with it. I guess that Skilhunt have ‘enhanced’ the way the indicator works - and it seems they screwed it up.

That’s definitely the correct number of seconds between flashes that I encountered. But unless I’m missing something it sounds like those flashes should only affect the indicator light, not the main LED itself. Perhaps that aspect is still a bug?

Flashing of the main LED is undocumented, unnecessary and unpleasant. That’s what I call a bug.

Agreed entirely. Thank you for your contributions.

I used the form to contact Skilhunt from their website, they did not clarify if it is a defect or a feature. Shipping would be $32, so I re-learned an important lesson.