Okay, the teacher always said there's no such thing as a dumb question, so here goes:
What do I need to do to take a stock, single cell flashlight and convert it to direct drive? I understand the concept, which is operating without a driver, but how do I get to that point? What about a light like the HD2010? Also, how would it react with an IMR 26650, or any IMR for that matter (for general learning purposes)?
There is going to be some resistance from the tip of the battery to the emitter through the spring and then the wires before the power gets to the emitter, you want to limit the flow of current here by adding resistance. If you used some really small wires and a small spring it might survive. With big wires and no spring or a large heavy duty spring it would probably turn an angry blue and self destruct after a while with that battery. I have some direct drive lights, but I limit the current with small wires and don't use batteries that will deliver a ridicules amount of current like a 26650.
I suppose ideally I would want two modes. I just assumed direct drive would be easiest, but maybe not. I'm looking for "turbo" (run time isn't a concern) and a workable low mode. That's all. I couldn't locate a driver to meet those needs so I started thinking about the direct drive approach. Based on your response I'll steer away from that when we're talking 26650 for a single XM-L.
The AMC7135 based 2.8A driver that Illumination Supply sells can be configured for two modes and will run on a 26650 cell.
I can add a couple extra 7135 chips to the Nanjg105C to give 3.1, 3.5 or 3.8amps for you if you want and you can select the 2 mode star and get exactly what you want.
So then does a 26650 put out more current then a18650? Thanks.
Keith
I think its more a case of: 26650s voltage doesnt sag so fast and voltage determines current. So the LED will be able to pull more current for longer time, tho there are limits. I've got XMLs that wont go over 3.5A but also one that easily consumes 4.5A..
Here is what I need to know. My Blues bro 3xaa/26650 pulls about 2.1 amps (about 450 lm) on an 18650. Will said light pull more amps (be brighter) on a 26650? I am not concerned with run time but whether or not i will benefit (investing in 26650) in terms of more lm with a 26650. Thanks.
Keith
Whats the emitter? My guess is it wont pull much more.
It's an XM-L.
Ok, now I get it. You are talking about the Blues Brother Maglite from OL. Well, its an XML with current regulated driver. Tho from the pictures I thought it was a 2.8A driver.. so it wont pull more, unless you make it DD or swap the driver. Or your 18650 cells arent good, I dont know what you got. :)
[quote=NightCrawl]
If a 18650 shows 4.15 can it still be bad? I guess it could be bad if it has high resistance? It is a ultrafire. It pulls the same amp as 3xaa NiMh. I was thinking bad batt but since it shows 4.15 I was not sure. So, bad batt? I The batts came with MXDL zoomie package deal. Probably rejects/fakes. I"m thinking a good 18650/26650 will give me more amps/lm. I"m learning. Thanks for the help.
Keith
some of the *fire cells from DX have quite high internal resistance, so they struggle to supply high amps, even though they do fine on lower power LEDs. If you can find some Samsung/ Sanyo/ Panasonic 18650s you should be able to do better :)
Don't forget that some drivers are direct drive on high (such as the HD2010). This is probably what you want - a driver which is direct drive on high. Other's can chime in on which drivers are available which are direct drive on high. I questioned a little while ago about whether direct drive drivers were really just inefficient.
-Garry
Yes. Is your DMM accurate? I just asked OL and he said it was either a 2.8 or 3A driver from KD. So either your DMM (the leads) or cells are bad.
Yes, I was aware it is at least 2.8 A and am using a Fluke that has been checked (at my sons work) so it is the crap batt. The MXDL was my first foray into 18650 so I was not sure what I was dealing with. Now that i am sure it is a bad batt I shall order some 26650"s. Right now the light is brighter then my JB-PA40 using 3xaa so am thinking about 500lm. A good 26650 should approach 1000? What you think? Thanks.
Keith
What AAs are you using? Eneloops should be able to drive it at max. But getting some better cells is a must. Along with a good charger, some 18650s and more flashlights.. and more flashlights.. :P
Eneloop, EneloopXX. 2.1 amp with each. Had my son check as well.
If they are all fully charged pretty much everything except for your meter is ruled out. Do you have clamps? Can you clamp the meter and then use a thicker wire in parallel to see if the light gets brighter?
Batts fully charged. As I stated i have a Fluke (my son gave me) that was calibrated against a new (son bought a new one) one so can rule out meter. My son is cert in electrical/hydraulic & sub contracts for Detroit Postal service. Keeps all their high tech electrical/hydraulic systems working in all their vehicles. I found out a short while back that he can do these mods in his sleep but is so very busy I did not wish to bother him with it. when he gets a break he is coming over to go through this with me and will bring his new Fluke with clamps. I do his auto cosmetics and he keeps my vehicles running properly. He will go through the light & find out why it is only pulling 2.1 amp. BTW, he also can do intricate soldering. He will figure it out. I just don"t want to invest in Li-ion for the light if they are only going to pull the same amp as NiMh. Thanks.
Keith