Jet MK-II Can’t run max lumens

[Norseman]

I have a Jetbeam Jet MK-II that I've had just over a year. All of a sudden it won't last on max lumens (510 lumens).

It runs off a 16340. So I'm wondering if the batteries have gone bad. This is why:

If I put in a topped off battery and I set it to high, it runs for 45 second and then turns off. Nothing I do will bring it back on. If I take the battery out and wait an hour for everything to "cool off " and put the battery back in I get no response. But if I put the battery on charge for even 1 second and put it back in the light, it will run. I can set it to medium (100 lumens) it'll fun for well over an hour. But as soon as I put it on high, in 45 seconds, it'll cut out and then I again have to swap the battery or put the one in it on charge.

My batteries were bought at the same time and are EAGTAC 3.7v 750mAh IC Protection.

I was wondering what everyone's thoughts are before I go buying another set of batteries.


Sent from my iPhone using Tapatalk

 

[scout24]

I would suggest another set of cells. Sounds like the protection circuit is tripping under high load.

 

[Norseman]

I would suggest another set of cells. Sounds like the protection circuit is tripping under high load.

Yeah that's what I was thinking but figured I would run it by fellow enthusiasts. Thanks.


Sent from my iPhone using Tapatalk

 

[peter yetman]

I think that's the correct answer. I was going to say knackered batteries until Scout said protection circuit, that's the one.
P

 

[Norseman]

Ok just ordered a pair of 16340 Efest IMR16340 V2 700mAh High Discharge Button top from illumn. Hopefully that'll sort me out.


Sent from my iPhone using Tapatalk

 

[peter yetman]

Certainly will, no protection to kick in.
P

 

[archimedes]

Not familiar with that particular model, does it have overdischarge protection ? (the torch, not the battery)

 

[Norseman]

I've read through the specs and it doesn't really say.


Sent from my iPhone using Tapatalk

 

[AVService]

Did you even try a regular cr123 to see if the light acts as it should that way?

 

[Norseman]

Did you even try a regular cr123 to see if the light acts as it should that way?

I haven't. It worked just fine for the longest time, so that's why I think it is a battery issue.

I'll post the results when I get the new batteries.


Sent from my iPhone using Tapatalk

 

[AVService]

I haven't. It worked just fine for the longest time, so that's why I think it is a battery issue.

I'll post the results when I get the new batteries.


Sent from my iPhone using Tapatalk

I also think it is just a battery issue but the cr123 test is such an easy way to make sure the light is OK that I had to ask.

 

[Norseman]

I also think it is just a battery issue but the cr123 test is such an easy way to make sure the light is OK that I had to ask.

Its definitely a good idea, but I don't have any. Back in 2012 Hurricane Sandy took out the power for like 2 weeks. I had a fresh box of CR123s and a Surefire 6P and then I had 2 cheepy Solarforces. We were able to get a generator to power appliances in the kitchen but the whole rest of the house was completely dark once the sun went down. So I relied on those flashlights a lot. I went through the whole box of CR123s in just a few days. After that I just always get rechargeables. I've got a few AA lights now too so they are my "go to" lights if I were not able to charge batteries.


Sent from my iPhone using Tapatalk

 

[AVService]

Its definitely a good idea, but I don't have any. Back in 2012 Hurricane Sandy took out the power for like 2 weeks. I had a fresh box of CR123s and a Surefire 6P and then I had 2 cheepy Solarforces. We were able to get a generator to power appliances in the kitchen but the whole rest of the house was completely dark once the sun went down. So I relied on those flashlights a lot. I went through the whole box of CR123s in just a few days. After that I just always get rechargeables. I've got a few AA lights now too so they are my "go to" lights if I were not able to charge batteries.


Sent from my iPhone using Tapatalk

Same here really.

 

[Norseman]

Ok here's an update. I charged my 16340s on my nicer charger today and with one battery, I see the same exact problem. However with the other, it runs for 37 minutes before it turns off. So 1) it's definitely gotta be the batteries. And 2) it's odd that when charged with one charger they both fail but when charged with the other, one of the batteries will work just fine.


Sent from my iPhone using Tapatalk

 

[Norseman]

Update: after using my better charger a couple times, now both batteries work ok. The light will run on high for about 37 minutes. Odd right??


Sent from my iPhone using Tapatalk

 

[scout24]

Brands and models of the chargers in question?

 

[Norseman]

The one that seems to cause the problem is the Fenix ARE-X1. The one that seems to have "fixed" the issue is the Eastshine S2.

I also did experiments with the EAGTAC battery vs. the OEM battery in my new S1R Baton II and they get very similar results. The Olight is 550mAh and the Eagtac is 750mAh but in actuality they're probably pretty close to the same output (based on my experimenting).


Sent from my iPhone using Tapatalk

 

[hiuintahs]

Ok here's an update. I charged my 16340s on my nicer charger today and with one battery, I see the same exact problem. However with the other, it runs for 37 minutes before it turns off. So 1) it's definitely gotta be the batteries. And 2) it's odd that when charged with one charger they both fail but when charged with the other, one of the batteries will work just fine.


Sent from my iPhone using Tapatalk

I have that Jetbeam flashlight. I normally will not run a 16340 battery on a light that is attempting to put out 500 plus lumens beyond momentary usage. I think that level is more geared towards bigger batteries or at least 16340 batteries with lower resistance. Still though it will get hot and I worry about long term wear out. I have done run tests with various 16340 lights but only on the medium modes. Mostly I am interested in the efficiency of the light. Another couple of batteries to keep in mind is the Fenix 16340 and the Klarus 16340. The batteries are protection type and are very similar to each other.

Having a handheld multimeter would be a good item to have when questioning why one charger behaves different than another. That way you can check the voltage on the battery after the charger thinks its charged up and see if it really is. I think the guys have addressed your issue which is either an aging battery generating higher internal resistance than when it was new, or a charger not charging all the way up. A charger that you may be interested in is the MiBoxer C4 Upgrade. That can be had for $25.99 on Amazon and has battery resistance measurement, voltage, & charges all battery types and sizes. For the longest time I have held off on buying a commercial charger because I have designed my own chargers. But when I got a flashlight that took the 21700 battery, I needed a charger that could accept the longer cells. I actually really like that Miboxer C4-Upgrade. Just thought I'd throw out my 2 cents on that :thumbsup:.

 

[Norseman]

Just thought I'd throw out my 2 cents on that :thumbsup:.

Hey thanks for the detailed reply!

I actually have a Drok multimeter and a UM4 Nitecore inbound.

I reached out to Jerbeam and they said try a new battery and let them know if it still happens and they'll see if they can replace it under warranty. That was awesome of them so I ordered a couple 16340 Efest that have good ratings. Plus I ordered a couple 16340 Olights. So since I have them incoming, I went ahead and took the battery out of my S1R Baton II and did a test in the Jet MK-II and it ran on high a little over 30 minutes (it did get hot but not too hot that I couldn't touch it).

While that was going on I had charged the Eagtacs in my Eastshine S2 and again tested them in the Jet MK-II. One failed after 30 seconds but the next one ran on high for 37 minutes. Then I tested the one that failed again (after putting it back on the Eastshine S2 to top off) and the third time it worked!

I then tested the 2 Eagtac batteries in the S1R Baton II and they work just fine.

So my conclusion is that the Fenix charger somehow causes the issue when batteries charged on it are used in the Jet MK-II.

To be thorough, I'm going to drain the 2 Eagtacs again, charge them both on the Fenix (one at a time because it only has one bay) and test them both again.

The UM4 Nitecore that I have incoming is capable of charging all sizes as well so I'm excited to get that. I'll do a test with that one as well.

I've got about a dozen flashlights and I'm doing all of this testing so that I know what i have, what works with what, what I can count on if I'm in a situation where I HAVE to rely on them ...that kind of thing.

If I'm going to be a flashlightaholic I'm going all in!! LOL



Sent from my iPhone using Tapatalk