Direct drive mt g2

Hi all

I have this one
http://www.ebay.com/itm/NEW-Power-W...243?pt=LH_DefaultDomain_0&hash=item232bb19743
It has 6v and 9.5a/h

I want to connect battery with mt g2. 6v version led (direct drive)
http://www.ebay.com/itm/Cree-MT-G2-...Power-Led-Light-Emitter-Bulb-4A-/321100696792

I'm interested in how many lumens can get this way?

That looks scary, check out the specs for the emitter on the Cree site, it should give you lumens and more important, Forward Voltage, which you shouldn't exceed. Unless someone can correct me.

The led linked to on Ebay is the older version MTG It is not an MTG2. With the MTG2 you would possibly get away direct driving the led from the six volt battery if it was on a copper star and that was mounted to a decent heat sink.

I am planning to make cooper heat sikn.
I found characteristics of that led and 6v version, max. amperage is 3a.
My batteryes voltage its ok, its has 6v, but i dont know its amperage. I know only capecity (9,5 a/h).
If amperage would be excessived, can it damige led bulb? :s

If all goes well, how many lumenis can be obtained in this way?

You need to do some reading, and CPF is the right place.
An Led will draw as much current as it can be supplied, unfortunately it can draw enough to destroy itself.
Normally you'd limit this with regulation, but you want Direct Drive - and why not? I love Direct Drive.
There's a way of limiting the current using Protected Batteries, which is what I do.
Read this thread http://www.candlepowerforums.com/vb/showthread.php?355592-Mini-Turbohead-M2-XML2-Direct-Drive. Particularly the bits by Electron Guru. There's a lot about which batteries work with Direct Drive.
Also you could use a Current Limiting Resistor, but you won't get maximum power.
I've read about Regulation Boards which can provide Direct Drive (almost) so have a snoop round.

There are a lot of people direct driving the MT-G2 off of 2 x Li-ion.

Basically, I think you need to see the maximum current that your battery will deliver (mah is milliamp hours or current over time not current delivery) and check that the current threshold doesn't exceed the current that your emitter can handle.
From your Ebay link you are looking at 2400 Lumens max. Maximum Forward Current 700ma. If your battery allows you to draw more than this, POOF!

Technical Parameters:
Quantity:1pc
Power: 6W~24W
Model Name: MT-G EasyWhite
Emitted Color: White
Color Temperature: 5000K
Highest Brightness: 2400LM
DC Forward Voltage (VF): DC36V
DC Forward Current (IF): 185mA~700mA
Maximum Pulse Voltage: 38V
Maximum Pulse Current: 900mA
LED Viewing Angle: 120 degree
Diameter: 20mm
Usage: House/Street/Architecture Illumination

Package Include:
1 x Cree MT-G1 EasyWhite White LED Light Bulb Emitter

Correct me if im wrong but I thought the current won't destroy the emmiter if it has proper & sufficent heat sinking to keep the emmiter cool.
I've used direct drive for my XML2 & MT-G2, and so far none has failed me yet just that they create alot of heat during the usage.

VOLTS need to be within the LED's limits. (If it is rated to take UP TO some voltage, don't go over that)

Its the AMPS that are going to be your variable as to the potential lumen output, and, resultant heat issues. Generally, the higher the amps, the brighter...and hotter, it will get.

Past a certain point of diminishing return, an LED might be making very little additional light compared to the additional heat....so, that point, or approaching it, is where (With a driver) you'd typically stop stacking resistors, etc....to keep it below that region, and, making a PRACTICAL output range.

When in DD, the CELLS are what drive it, so, its ALL about how many cells (The voltage) and, THEIR amps at that voltage over the discharge period. So if a certain cell combo can produce a certain amp supply at that voltage, that's what you are driving the LED at.

If the HEAT is able to be handled at what the CELLS are able to supply, your DD is good to go.

As the cells drop in amp output, the light dims. It won't dim until the draw has reduced the cells' ability it keep up, and, the amps start to drop.

Thanks guys!

I got a lot needed advice.

It isn't my purpose ro built without driver, but I haven't found any driver for mt g2 led,
wich would work with 6v battery range

Zener mod.....
I believe Mountain Electronic sells them

Direct Driving an MTG2 is a fantastic way but none of those links you reference are good my 2 cents.

The MTG2 can be purchased from USA seller on copper board for under $20 at Mtnelectronics. While there they sell a $12~$13 dollar FET Direct Drive Driver with 5 modes if you want modes and Direct Drive.


The MTG2 in direct drive works absolutely perfect via 2 Li-on cells aka 8.4V input.



Easiest way to build an MTG2 DD with 8.4V input is go the 2C Maglite route. I have built three 2C Mags with MTG2's direct drive. You don't even need battery spacers or the bodies to be bored. Mtnelectronics has IMR 26500's (exact size of 1C alkaline). With 2 of those in the Mag tube you get 8.4V input.

Best,
biGC

Very good informations for me!

So you say that i will get good results without driver. Can you told me about haw many lumens would i get?
I want to build with driver, as guys sad above, without driver may overheated and damaged led, but all drivers has few modes and i want only 1 mode

To modeficed maglite with mt-g2 led its good idea! I am planning that, but its an other project.
1. you say that 2x26500 can get 8.4v . You may mean 4.2 volt versions, but there are also 3.7 volt versions. And as i know when cells anssambled, voltage reduced. 4.2v + 4.2v will not 8.4v, but 8v. Also 3.7 + 3.7 will be about 7volt and it will be good for mt g2 6v veraion led for DD.
2. If i built that one can stock maglites swich withstand that current?

srt-8 said:

Very good informations for me!

So you say that i will get good results without driver. Can you told me about haw many lumens would i get?
I want to build with driver, as guys sad above, without driver may overheated and damaged led, but all drivers has few modes and i want only 1 mode

To modeficed maglite with mt-g2 led its good idea! I am planning that, but its an other project.
1. you say that 2x26500 can get 8.4v . You may mean 4.2 volt versions, but there are also 3.7 volt versions. And as i know when cells anssambled, voltage reduced. 4.2v + 4.2v will not 8.4v, but 8v. Also 3.7 + 3.7 will be about 7volt and it will be good for mt g2 6v veraion led for DD.
2. If i built that one can stock maglites swich withstand that current?

Click to expand...

Al Li-on cells that are 3.7V are actually 4.2V fully charged. Here on the forum we based the battery/cell Voltage based on when its charged. So, yeah you buy 2 of those IMR 26500's which combined actually give you 8.4V when fully charged. When you see 3.7V its actually a good time to recharge them again.

MTG2 6V with direct drive will give you 3A at the tailcap or up to 6A at the tailcap with 8.4V input. So, you can get 2000 lumens or 3000 lumens but since its direct drive you have to way of knowing the vF until you buy it and try it. The vF (forward voltage) the lower it is the more amps you get at the tailcap and the more lumens but again you don't know the vF until you buy the LED and test it.

Stock Maglite switch can handle 6.5A or so.

Stock Maglite switch with FET Direct Drive Driver (yes, its a driver that gives direct drive) with this FET you can push it 15A or more since the current skips the switch the FET handles the load and from the vendor he claims it does it while remaining cool, so you don't need to heatsink or pot the FET driver

It is possible to bypass all the modes and make it into a 1 mode driver.
You can get regulated output with 1 mode.

The other issue with direct drive is that the output will be very bright at the start & will start to sag as you use it.
Well, this may not be an issue if you don't mind it.

srt-8 said:

I want to build with driver, as guys sad above, without driver may overheated and damaged led, but all drivers has few modes and i want only 1 mode

Click to expand...

Use the LD-4B from International Outdoor. Will work fine for the OP. You can order them in single or 3 mode. It's what I use for my XML EZW builds.

Inspired by this thread,

2D Maglite, ha22 heatsink, MT-G2 on star from Mountain electronics and a pair of TrustFire 6000mah protected 32650. Direct drive no resistors, at the tail cap I get 5.5 amps which settles to 5 amps after a few seconds. I have only run it for five minutes at a whack because the body gets so darn hot quick. The light output is great but it gets too hot too quick.

Thanks guys.

Add a JM-PHD-D1 and you can dial in whatever current you want and add modes.

I have almost the same with. 2D mag, Ha22 using 26650 IMRs. I used Jimmys FET regulator for Mag D to run it.
I can run it full bore with overheat protection, or I can run it medium where it'll only consume 750mAh, but give me lots of useable output and run forever between charges.

http://www.candlepowerforums.com/vb/showthread.php?398562-Easy-Peasy-XHP70-Mag-2D-Build

Conte said:

Add a JM-PHD-D1 and you can dial in whatever current you want and add modes.

Click to expand...

The BLF DD fet drivers as sold via mtn are a more suitable choice for this than JM's incan drivers.

Yeah, actually, if direct drive is what you want.