No wonder the Jetbeam MkIIx gets so hot!

Just finished my SSC P4 mod to an Inova T3 and was measuring its curent draw, but I got carried away and measured the power consumption of every flashlight I could find to hand:

Model Amps Volts Power in watts
Jetbeam MkIIx max 1.64 4.13 6.77
Inova X03 SSC mod 0.51 5.90 3.01
MagLed AA 0.40 2.594 1.17
Terralux Ministar 0.25 2.58 0.64
Jetbeam C-LE max 2.3 1.27 3.27
CMG Infinity 0.04 1.5 0.06

I was quite surprised by these results but I can repeat them. The Mag-LED is supposed advertised as 3watts but mine only seems to draw 1.17watts on fresh alkalines, less on NiMH where it draws only 0.33A.

The Jetbeam MKiix seems to be drawing nearly seven watts. Mine gets hot to the touch very quickly but it is unbelievably bright even next to my P1d CE (not to hand for testing).

Are you measuring voltage and current simultaneously, so that you are capturing the voltage of the power source under load?

:thinking:
wonder that the Led on Li-Ion draws this much. Goes nearly directly into the led and might kill it soon.

Normally not even in full direct drive (Li-Ion 18650 <-> Cree/seoul, without resistor) there should not be 1.5 A
(but not sure, I wont try that)

if it were a Ni-Mh, it wouldnt be a surprise
Jetbeam uses 1 AA and draws 1,6 A
divide by 3 (to get to ~ voltage of the Led) = 0.533 A
multiply with 0.85 (circuit loss) = 450 mA
450, that should be some 100 Lumen out the front

Yeah, you need to measure the voltage under load to get a more accurate reading. Even so, measuring current and voltage at the battery/ies is only giving you a power reading drawn from the battery/ies. To get a true Watt rating, you need to measure current and voltage at the LED.

1.6 amps being drawn from the single AA battery is more than most lights, but not outrageous. Many Elly single AA lights from DealExtreme draw around 1.2 to 1.3 amps, and only deliver about 250 mA or so to the emitter. You have to remember that the circuit boosts the voltage to ~3.5 V from a 1.2V battery (under load). Nothing's for free, so this voltage boost comes at the expense of more current being drawn.

But the bottom line is that it's BRIGHT! :twothumbs

Good point, I'm not measuring current and voltage simultaneously, so the voltage is without load.

I think the MkIIx is direct drive at higher voltages, so the current might be in the expected ball park. The discrepancy from the predicted 1.5A might be inaccuracy in my meter, or sample variation among the crees I suppose. Any thoughts. Whatever the reason, it seems like a lot of power to pump through a LED in such a tiny flashlight...Why is it brighter than a L1D CE with the same cell, also on direct drive? (Not to hand to measure)

What really got me was the Mag-LED drawing so little. It didn't seem any dimmer with the meter connected in series so I don't suppose the resistance of the meter is all that great, but I could be wrong.

I burned out my MkIIX using a wolfeyes 3.7v AA sized battery. Clicked it on and it ran bright for 5 secomds and shut off. Bummer, brand new light.

Ken

Oops. I've had about five hours use from my MkIIx and its going strong. Are you going to try out the lifetime warranty?

The current will be relatively accurate at the highest DMM setting, but the voltage will be way off if you are using the no-load voltage. The higher the current, the further off your voltage will be.

A second DMM to measure live voltage is the way to go, along with some battery holders and test leads with alligator clips to remove the battery. You will know exactly the power coming out of the batteries and going into the driver. If it's not direct drive, you can estimate 70% driver efficiency. (Power to LED = 0.7 * power from batteries).

Forgot to mention...Julesb, welcome to CPF! If you're measuring currents from your lights, you're already hooked...but I can see that by how many lights you already have.

Oh look! He is a new guy!

Thanks for contributing information already. We're just trying to be helpful

julesb said:

...
Model Amps Volts Power in watts
...
Jetbeam C-LE max 2.3 1.27 3.27
...

Click to expand...

There seems to be a disconnect. Netkidz runtime graph of a CLE (see first post here) shows the CLE running 2 hrs on a 2000 mAH nimh on high. That suggests that it's drawing no more - and probably a little less - than 1 Amp on high.

I HOPE the CLE doesn't draw 2.3 amps off a nimh....

That suggests that it's drawing no more - and probably a little less - than 1 Amp on high.

Just double checked...on the first setting it draws approx 1.1 amps, on the second 0.25 amps, and the third 2.3 amps again.

Also checked the MkIIx, this time with AW's protected 14500. It drew 1.4 amps

julesb said:

Oops. I've had about five hours use from my MkIIx and its going strong. Are you going to try out the lifetime warranty?

Click to expand...

Yes, I'll post a not here about how the warranty service is. Hoping for a replacement.

Ken

I think there is something wrong with your meter. I measured the C-LE current as: .90amps - high
.45 amps-med.
.089 amps-low

C-LE V1.2: .98 amps-high
.37 amps-med.
.089 amps-low

I'll try another meter.

Just finished my SSC P4 mod to an Inova T3 and was measuring its curent draw, but I got carried away and measured the power consumption of every flashlight I could find to hand:

Click to expand...

Does no one want to know the results of the Inova T3 modding?

Some pictures?:naughty: Did you use the 2007 version or the Tiros type?

How bright is it? Has anyone else modded sucessfully another T3?

Mr.Urahara


P.S: You probably fried the fine-fuse in your Multimeter, without you probaply get false results.

Are you folks using the same battery type as julesb? His meter may not be defective. The current used by the torch will depend on the input voltage available. Whether it goes up or down will depend on regulation. If you use Alkaline, Lithium, NiMH, Lithium Ion, etc. the current will probably be different for each.

I had a Jetbeam C-LE (not Mk II) that was drawing 2.0A from a NiMH. The same NiMH in my Cree Elly, drawing 1.4A, was significantly brighter. They must be using some sort of extremely inefficient converter circuit (which will simply waste power and generate heat inside the light).

The mod was to the TIROS version...and although I said T3 it was in fact to an X03. I didn't take pictures of the process as this has already been done by another member:

https://www.candlepowerforums.com/threads/97753

The beam - tested at night it is very effective. The very centre of the beam is extremely bright and it reaches further than any of my other torches. A thoroughly worthwhile project in my opinion, as the X03 was not getting much use having been thoroughly outshone by more recent purchases.

jled said:

I think there is something wrong with your meter. I measured the C-LE current as: .90amps - high
.45 amps-med.
.089 amps-low

C-LE V1.2: .98 amps-high
.37 amps-med.
.089 amps-low

Click to expand...

The Jetbeam C-LE I got from CEJ's group buy draws about the same power as yours.

The 2 Jetbeam C-LEs that I got from Deal Extreme draw even more power than Julesb measured. The higher of the 2 is pulling 3.3 A on high. It puts out over 90 lumens on high initially but the output starts dropping immediately probably due to both LED heating and the NiMH not being able to maintain voltage under that load.

Both the DX C-LEs are almost impossible to switch levels as the off/on has to be ridiculously fast. Both are being returned as they were intended for gifts for folks who don't use recharge ables and will be unuseable on alkalines. Unfortunately DX won't provide a refund only exchanges. Probably my last Jetbeam or DX purchases.

Mike