Horrendous runtimes on 14500s - help???

[hyperloop]

Need some advice from the experts here, I am no technical person, dont own a voltmeter or any such devices.

All i have are a Jetbeam Jet I, Mk II with some Ultrafire protected 14500s and a WF-138 charger.

The runtimes i am getting on the highest mode of the Jetbeam is less than five minutes whereas runtime with a 2000mAh Eneloop is 120 minutes and still going strong!

I got 14500s for more power but the short runtimes are really annoying me.

Are my cells defective?? Or is it a charger problem?? Thanks guys

 

[cl0123]

Are you referring to these? I think in the AA-size category, NiMH cells give you more bang for the buck. Eneloop (LSD) does hold more capacity than your 14500 cells.

Hope that helps.

With Aloha,

Clarence

 

[hyperloop]

Hi cl0123, yeah, those are the exact cells that i am talking about. Could i have damaged them in some way?? I didnt expect runtimes to be that short. On an eneloop 200mAh its been over 120 minutes and the Jetbeam is still going strong on the highest mode with loads of usable light.

 

[Mr Happy]

According to this page, you could expect up to half an hour of max output on a 14500 cell.

However, this might depend on the quality of the cell.

Those UltraFires are claimed as 900 mAh, but that could be optimistic. Let's suppose they are actually more like 600 mAh.

If the light drew a current of 1 amp, you would get about half an hour. If the light drew 2 amps, you would get about 15 minutes. I don't know what the lamp actually draws, but I suspect it is in the 1-2 amp region at max brightness.

If you are only getting 5 minutes, something isn't quite right. Maybe your cells are not being fully charged, or maybe they are faulty. It is hard to say.

 

[hyperloop]

I would assume so, but my Jetbeam is sooo old that it isnt even listed on that page this is the jetbeam that i own http://www.candlepowerforums.com/vb/showthread.php?p=2597528#post2597528

 

[Black Rose]

All i have are a Jetbeam Jet I, Mk II with some Ultrafire protected 14500s and a WF-138 charger.

What is the charge selector on the WF-138 set to? 3.0V or 3.6V?

 

[Fallingwater]

It might be that the cells are bad. Ultrafire is known for being a dodgy brand - Trustfire is generally thought to be better.

 

[hyperloop]

What is the charge selector on the WF-138 set to? 3.0V or 3.6V?

Doesnt seem to have a charge selector, however the output says 3.6v. Man, this is bad, i just did a runtime test and the Jetbeam on lowest output ran for only 3 hours.

Think it may be the cells, I ordered some Trustfire protected 18650s and a new WF-139, think i will wait till they get in, run down the Ultrafire cells and recharge them in the WF-139 and see if there is any difference.

I think you guys may be right and its the cells cos an eneloop runs it for 3 hours on high without much diminishing of output (naked eye test) while a generic 1400mAh cell ran it on high for about the same time (though with diminishing output)

 

[Black Rose]

Doesnt seem to have a charge selector, however the output says 3.6v.

Sorry, I forgot that there are two versions of the WF-138 - one for RCR123 cells (has the selector switch) and one for 14500 cells.

 

[matrixshaman]

Older Jetbeam electronics were not the best - I've seen various problems and what appeared to be poor designs. Newer ones have gotten better. You do realize the 18650's won't fit this light I assume?

I'd guess you probably have a bad 14500 if this is the only one doing the very short runtimes. Mr Happy is right on in his estimates of what you should be getting. If you want the best 14500 cell get one of AW's here on CPFM from AW or Lighthound.com or fenix-store.com all have them too.

 

[hyperloop]

i'm going to miss the brightness of my lights running on 14500s but the runtime is simply too low to make it practical to use it for an EDC, most likely its the cells. is that the general consensus?

 

[PhantomPhoton]

Yea I'd say its the cells. I get much better runtimes off of my 14500s using a Jetbeam MkIIx and MkIBS as well as my NDI.
I find that in the dark the difference in brightness between a 14500 and an Eneloop is barely noticeable.

 

[hyperloop]

Older Jetbeam electronics were not the best - I've seen various problems and what appeared to be poor designs. Newer ones have gotten better. You do realize the 18650's won't fit this light I assume?

I'd guess you probably have a bad 14500 if this is the only one doing the very short runtimes. Mr Happy is right on in his estimates of what you should be getting. If you want the best 14500 cell get one of AW's here on CPFM from AW or Lighthound.com or fenix-store.com all have them too.

oh yeah, the 18650s are for another light, i guess i will just stick with 200mAh eneloops for the time being. Thanks again for all the input guys

 

[5kids]

I had one dud 14500 protected ultrafire from DX (also using the WF-138 charger). This runs my L2DQ5 for run about 50 minutes on turbo, 1hr30min on high, 2hr45min on med, and 3hr40min on low. I contacted DX about the bad cell, and they sent me another 2 pack no charge. Love the brightness of the 14500, but lose the low levels on the Fenix.

 

[hyperloop]

think that it must be my cells, could it have been an overcharging issue??? think there was once when i left the cells in the charger overnight

EDIT: to quell my doubts once and for all, how do i test my batteries?? Am new to this, what equipment do i need to buy?? Might as well get it now and save all this speculation

 

[cl0123]

You have many good responses. I'd like to make just one more suggestion. Do you have access to any AA-size primary cells? Like an Energizer or Duracell equivalent? That would be a good test for your light's electronics. If the primary lithium cells delivers just another few minutes of light, it may mean the electronics on your light cannot handle the higher voltage of lithium cells (your 14500 may deliver even higher voltages, you need to test them). Otherwise, if the primaries work fine, chances are you can isolate the problems to the 14500 cells.

Best of luck to your Jet!

With Aloha,

Clarence

 

[hyperloop]

primaries are fine, Sanyo 2o00mAh eneloops can power the Jet on high for 120 minutes and still going strong. Possibly cos its unprotected and all but the light output was still very bright

 

[Flashfirstask?later]

I would assume so, but my Jetbeam is sooo old that it isnt even listed on that page this is the jetbeam that i own http://www.candlepowerforums.com/vb/showthread.php?p=2597528#post2597528

What.. its not that old , just over two years ...as I still use it as my main edc with a AW 14500.

Are the Ultrafire 14500 the only ones you have? I only have AW and some generic blue ones that I got from Mark at http://e-lectronics.net/ before getting the JetBeam Jet 1 mk1/mk2 lights and they all work great in the Jet 1 mk2/

 

[hyperloop]

well, i am thinking that i may have overcharged the 14500 cells or perhaps they are just defective. In any event, i am switching to 2000 mAh eneloops for my Jetbeam (also my primary EDC as it serves all my needs) with an E01 as a backup.

anybody can tell me how to test a cell?

 

[mdocod]

um..

you are using an unprotected cell, the jetbeam has undoubtedly destroyed the cell by over-discharging it, probably happened on the very first run you used the cell on, from there on out, the cell has been toast, if you've been trying to recharge it and test it over and over, you're lucky it didn't blow up.

The Jetbeam, and other similar style lights need to be used with protected 14500 cells, otherwise you will have no way of knowing when you have severely over-discharged the cell and destroyed it.

Get an AW brand protected 14500 and I can almost guarantee you will get good runtimes (~30+ minutes). Try to make a point of charging it up before the cell shuts down though whenever possible. Top up the cell whenever you have used some runtime and have the opportunity to do so.

Eric