MTG-2 Driver Help

Hi all,

I recently modified a 6D Maglite using a 6V MTG-2 and this driver. Now despite using 6 D-cells for a total of 9V, I'm getting some weird behavior in high mode that suggests voltage sag (I changes between H-M-L every second and just repeats. Note this is NOT what the specs list as a low voltage indicator). Given that an alkaline D-cell should handle 3 to 4A (?) I'm guessing the driver just may not be up to the task for whatever reason. That being said I have tested the setup with 2S Panasonic NCR18650 cells and high mode works fine even though fresh off the charger the pack voltage is lower (8.4V versus 9V).

So...what can I do? Are the six D-cells letting me down here? The build is for a friend and they really wanted to be able to use standard D batteries. Can someone suggest an alternate driver that provides less current but can supply the right voltage from the 9V source? My only stipulation is that it be relatively cheap if possible. My friend paid for the build but seen as it's technically my fault the driver is unsuitable, a replacement is coming out of my pocket...which he doesn't know about because there's no reason for him to worry

Any suggestions are highly appreciated. I'm all ears!

Thanks,

- Matt

Energizer D cell PDF looks awfully flaky beyond 1.0 amps. As a WAG, your voltage drop at 3-4 amps takes you well below 1.0v per cell. The driver probably realizes it's starving (Too-low voltage), changes modes, and then gets a different voltage at that different current.

Alkaline Battery Shootout

Scroll down to where the D cells are tested. Alkalines are ideal for two things: low drain applications and leaking. If you want to use D cells use Nimh instead.

i wonder where you got the idea that D cells can put out 3+A????? they start to crap out at 1,5A when fresh.

you need driver with lower power, something like this 6-15V, 3A Circuit Driver for Bike Light from KD, only has 1 mode, however.
but that is what KD has, you can use taskled b3flex driver (would need to have mag switch moded for momentary button).

but you'll be using only 1\2 of the led's power. kinda waste, you could have xml and have tighter focus due to smaller die.

alpg88 said:

i wonder where you got the idea that D cells can put out 3+A????? they start to crap out at 1,5A when fresh.

Click to expand...

Misguided youth? Haha, seriously though I built a 3A XML light using a mag3D and it didn't seem to suffer at all...I've even built a 4A model from a mag4D since then and it doesn't appear to have issues either. Both used linear drivers though, and in the case of the 4D light even voltage below 1V per cell would still allow the XML to run without issue.

I'll have a look at the NiMh suggestion. Not quite stock D-cells but makes full use of the 6D tube.

Sent from my Galaxy Nexus using Tapatalk 2

@Mattaus

So did it work with the NiMHs? I'm looking for a MT-G2 driver eswell and this one seems like a good option. Looking to drive the MT-G2 in also in a 6D Maglite at the beginning with 6 Eneloops in battery adaptors.

rayman

i too build few maglights with xml and p7's that trun on alk. D and very bright, 3d lights that use amc boards max out at 1,5A but they are still bright, compared to original bulb, night and day.
but still no 2,8A. situation a bit better with 4cells, but not for long.

http://www.mtnelectronics.com/opencart/index.php?route=product/product&path=67&product_id=53
This is the board being used for quite a few 2 x Li-ion setups for the MT-G2.

http://www.kaidomain.com/product/details.S006371
This is another board being used in a 2 x Li-ion setup for the MT-G2, being a "buck" setup this may work for you.


Note - I got this information from other folks looking into a 2 x Li-ion setup for a MT-G2

Rayman - yes with NiMh cells it worked fine. Full current measured at the tailcap was as expected and as far as I know the owner of the light has had no problems with it at all

Great, than I'll go with this one . Wasn't sure about those 2x Li-ions as I will have a higher voltage with 6xAA fresh of the charger but thanks for the recommendations.

rayman