KC1 keychain light is available now

Some recent update regarding this situation,

All the orders stuck at this status before have all been delivered at the end of July.
“2020-05-10 16:05:00 CAYVR / Despatched to overseas”

But those packages below are still stuck there, I can’t tell when they will move,
but as far as I can tell they will move at any time of this month
“2020-05-22 16:08 CAYVR / Despatched to overseas”

And they are the only packages to Canada which are still stuck on the way, I’m sorry for the inconvenience.

For example, this is one of the package stuck at 2020-5-10, there is no movement from 2020-5-10 to 2020-7-24

2020-07-29 16:31:00
/ Item delivered
2020-07-29 11:17:00/ Send item out for physical delivery
2020-07-29 06:42:00/ Receive item at delivery office
2020-07-28 18:43:00/ Receive item at sorting centre
2020-07-27 01:00:00/ Receive item at sorting centre
2020-07-26 17:14:00/ Transit to Destination Processing Facility
2020-07-25 05:01:00/ Held by Customs at Destination
2020-07-25 05:01:00/ Arrival at Processing Center
2020-07-24 23:25:00/ Arrival at Destination
2020-05-10 16:05:00CAYVR / Despatched to overseas
2020-03-31 23:30:59HK / Hand over to airline.
2020-03-31 14:54:00/ Information Received
2020-03-31 14:18:37Domestic Air Cargo Termina,Shenzhen,China / Depart from facility to service provider.
2020-03-28 19:07:05Hongqiao,Shanghai,China / 4PX picked up shipment.
2020-03-28 19:07:05
Hongqiao,Shanghai,China / Shipment arrived at facility and measured.

YUP ! My light is probably chilling with yours =P

There’s several of us!

Even with the extended wait, I still look forward to getting my KR4 when it finally arrives. Been waiting since early April to get it.

It looks like E21A 2200K is no longer an option on the website. It had a good tint below BBL, I hope it will be back or (even better) be replaced with E21A 2000K.

Anyone with a KR4 experienced this problem?

I received a KR4 Ti today.
Everything appears to function as it should except thermal stepdown.

Once the light gets hot it does not step down, instead the light shuts off completely, including the AUX LEDs.
It feels like the outside of the light reaches around 65°C - 75°C.

When the light has cooled down a little after a minute or so it comes back to life, the AUX LEDs come back on and the light can be operated normally until it heats up again then it shuts off.

I have tried resetting the light and thermally calibrating but it is still the same problem.

It looks like the thermal stepdown is not working properly and so the driver is heating up then triggering a thermal protection in the driver, if it has such a safeguard?

My normal questions don’t apply, since you’re you and you know better. However, could you post the firmware version? My understanding is a 15-click from off should blink it out in YYYY-MM-DD format (though I don’t own anything with a new enough version to do this).

It sounds like the sensor may need to be calibrated. Have you tried doing a factory reset with the light at room temperature?

It also sounds like the battery might be getting overloaded and shutting down until it cools off. Something is causing it to disconnect power, wait, then reconnect power.

I don’t know for sure that’s what is happening, but the issues described could be caused by bad calibration and a cell which isn’t strong enough to sustain full power. Recalibrating it could probably fix one issue and avoid the other.

Oh no! It looks like I waited too long to place my order… patiently waiting to see if it comes back.

-Randy

Interesting. I have recalibrated it at RT and also factory resetting.
Tried 30°C room temp calibration setting with 40°C limit, light still gets roasting hot & shuts off.

Cells I have used are brand new Shockli 1100 mAh 18350, Vapcell 1100mAh 18350, Sanyo GA 18650 and 30Q. The GA is new, 30Q quite old.

I did consider it may be the cells but doubt it with the same behaviour with all even at only 5A current draw.

Awaiting Hanks response.

I’m glad I got the 16x 2200K mule. It’s a good amount below the BBL. Every batch is different. The next batch might not be as good.

Yup, sounds like you tried all the right things.

Does it otherwise work? Like, if you set the ceiling to full power, can it ramp all the way up and back down normally? I wonder if it could have a broken chip letting power through even when it’s told not to.

Yes the light works perfectly otherwise as far as I can tell.
Original ramp limit, double click turbo, setting ramp at max etc.
I only realized something was wrong after a while when I decided to check how the thermal stepdown would perform and found the new shutoff feature.

Not sure what’s wrong with it. I tested that firmware version, but only with aluminum. I don’t have a titanium model to test.

Results looked like this:


I’m guessing the titanium and copper version might ramp down a little slower since copper takes longer to get thermally saturated, but it may end up stabilizing at a lower point since titanium isn’t very good at shedding heat.

Anyway, whatever it’s doing, your KR4 behaves in a way I haven’t seen before. Overheating suggests it’s failing to regulate down for some reason… and then the shutoff, delay, and boot-up blink suggest power is getting interrupted while it’s hot. But I don’t know why or how.

The closest issues I’ve seen are:

  • Some K1 12V drivers have blinked off and on while hot, if the boost chip isn’t heat sinked quite right or if the thermal limit is set too high. This is because of the boost chip’s built-in protection shutting it off.
  • I have a particular 26650 battery which makes my D4S runtime tests go crazy. The battery overheats and then causes output to jump around wildly.

I’m not sure if the KR4 has any chips onboard which would cut power when hot… I haven’t managed to cause that to happen even if I keep activating turbo manually to keep output higher than it should be.

D4V2 Brass is now D4V2 CuZn, according to the writing on the tailcap. I like it.

I wonder if D4V2 Ti is now D4V2 CuTi.

Thanks for your input, here’s some additional information.

Ok, so another quirk happened, the light refused to change between stepped & ramped output modes and would not reset via the 13H method, I had to use the tailcap version to reset it after a couple of attempts.

I did some runtime tests at various outputs after resetting the light to factory settings.
It does seem to ramp down but then just cuts off within a minute.

Hank has replied to my email and asked me to return the light which I will do.

Bummer, always happens when you REALLY are looking forward to something - I’m sure Hank will sort it though, he is for sure one of the ‘good’ guys out there.

A question for any new KR4 Ti owners out there. Does yours have a slight gap between the copper head and body tube? As shown in the photo, mine is tightened down all the way and still has a gap. The titanium can be seen reflecting light inside the gap. I’ve tried without a battery and it’s the same. There seems to be less of a gap when using a 18350 tube, but still there. I wonder if the light’s tolerances were created with anodized aluminum and not compensated for the non-coated copper? It doesn’t affect the function of the light, but it might trap debris in the gap. I might end up 3D printing a gasket to bridge the area.

Mine has a slight gap, but not as big as yours.

My brand new D4V2 CuZn E21A 2200K has a weird issue.

Sometimes, but not always, main emitters stay on even after I turn off the flashlight. They are at a level somewhat higher than moonlight. I don’t know how to trigger this issue yet. It happened on its own after I did not use the flashlight for a few minutes. Once it happens, simply using the flashlight or disconnecting the battery does not make this issue go away. It does somehow go away on its own.

I have seen it both start and stop happening while I was not using the flashlight or pressing the button. It was turned off.
Reset does not fix it.
It happens regardless of the level the flashlight was ramped to before it was turned off.
It happens with all aux led settings.
Even using manual lockout and turning the tailcap, pressing the button to make sure battery was disconnected, and then undoing the lockout doesn’t make it go away.
Everything else seems to work fine.