Something in my driver mod is causing high parasitic drain. Last night the cells were down to close to 1 volt each. I've put a warning message at the top of the OP.
You could try to see if itâs in a measurable range on your DMM. That would make it easier to troubleshoot. If youâve got spare parts it might make sense to build a clone of your driver for bench testing instead of having to repeatedly tear down this light
Thinking my DMM's are not sensitive enough, but I will give it a shot. Excellent idea on the clone.
This is the same driver that froze up in a medium mode a couple times. You and ToyKeeper suggested that it could be corrupted FW or MCU. Maybe this problem is related. I guess the clone could be a useful tool in helping trouble shot that type of problem too.
Another thing to consider, I changed the LVP resistors and the Sleep cutoff setting in the FW, but never tested those final 2 changes. Guess I can test that first since it is a fairly quick process.
Thanks wight. It may be a while before I get to it, but I'll report back on results.
If the light is getting pulled down pretty quickly it may be measurable on a cheap meter.
I wouldnât worry about low voltage step-down or cutoff. I assume when you say sleep you mean what I call LVC (cuttoff), right? If so I canât see how changes there would cause parasitic drain.
The firmware might not be sleeping the MCU properly in âoffâ mode. That would cause 3-8mA or so of parasitic drain I think. Iâd try to measure it and if itâs measurable then flash the regular STAR momentary and see if that fixes it.
Yes, LVC. More important than sleep, it is also supposed to turn off the PWM that ends up opening the gate. I agree it doesn't seem like the culprit, unless I changed the value from 115 to 12 instead of 120, or some mistake like that.
Another idea just came to mind. There is some light that was recently determined to not totally shut off when the voltage sense resistor bank was shorted. Don't recall which light. It's fairly recent. Maybe adding two R33's is causing the drain. A few possibilities to eliminate.
I really like your idea of trying to replicate the driver first to see if it behaves the same way first. After the problem is hopefully identified and corrected, I could use the clone in one of several lights that are waiting for some attention.
Sounds like a good UI, although im not that into tactical stuff. Still, I would like to try it when I eventually get around to flashing drivers... :)
[quote=ImA4Wheelr]
Hmmm, None of my MT-G2 satisfy me yet for various reasons.
[/quote]
One day you and I might have to realize that there is no such thing as the perfect flashlight. Until then, we will continue to buy and mod! :beer:
No sure if it's tactical FW or not, but it's very sweet. JonnC and Tom E made something nice with that. I know, it's hard to detect that I like it a whole lot.
One flashlight that I really like a lot for a whole bunch of different reasons is that TK75 you reported on here. Mine is still unmodded. My wife and I are using it all the time.
MT-G2 + versatile UI with super low and extreme regulated output. Quite nice form factor, etc.. Who wouldn't like it? :) Seems like you have created a great light..
Yeah, the TK75 is a sweet light. The one in my mod thread got sold to a local (I had a feeling he would choose that light after testing it). So Im making another one for me. Work in progress, but I cant wait to have one up and running again. Might play around a bit with emitters and maybe do some experimenting with DC-fix...
What would be a brighter light? Stuck between crelant 7g10 mtg2 or thrunite tn30. Never seen them in person. Hoping someone in here has both and can help me decide.
Hi, jamesjackson and welcome to the forum. I don't have a TN30, so take my input with a grain of salt.
Stock, the TN30 will trounce all over the 7G10. The 7G10 is severely under driven and has other significant issues that need to be corrected to make it competitive with the TN30. Not sure which one would win if both were modded. I would think the 7G10 would win due to 15mm wider reflector, more cell capacity and better heat sink potential.
ImA4Wheelr, thanks for the lead to your mod, excellent info!! Bookmarked! This will come in handy!!! 
Thanks KawiB. The copper in the head was overkill, but it was something I wanted to try out.
Looking forward to what you do yours using the XHP70 (90CRI). Seems like it will be a great combo. Hope you do a build thread on it. The 7G10 doesn't get enough love.
I will and post here on your thread if thatâs ok?! 
Itâs just where it falls in the line up of my winter mods? (2) Couruiâs (3) Jaxâs X6âs (1) BTU Shocker (2) Uranusisonfire 818âs (2) SD75âs (1) Crelant 7G10 and my ever evolving TK61 XHP70 build? Thatâs if nothing else comes along to make the list longer? Got to have something else to do during a Michigan winter besides hunting and ice fishing! :bigsmile: Thanks ImA4Wheelr
My SUPER âGâ (7G10) MOD 8) The bank of R056âs were wiped off and wire/solder jumped, the (3) FETâs replaced with RMMâs N Channel MOFSETâs DPAK-2âs. The driver+ via, soldered up with 18awg, to make the post contact, 18awg to the LED lead, 18awg grnd. I made a aluminum heat sink with a 16mm x.700mm deep pocket,(press fit) to allow half the emitter board to be exposed to center the reflector. Added a brass post to the battery carrier, and bypassed all springs. The MT-G2 is pulling 9.6 amps on VTC5âs, 9amps on 25Râs and the driver still retains the smooth ramping 2 level UI which is outstanding to me!!! How could this thing NOT be LOVED! :bigsmile:
I bet that really awoke the the full potential of that light! Well done! Has the ramping been effected in its reliability of operation?
Woops almost forgot?
Again who couldnât love this thing? :heart_eyes:
No FP smooth as silk! I just could NOT give up on it because of the UI! The earlier problems of the rapid lumen drop with the XHP-70 was due to poor heat sinking, I just got some 16mm XHP-70 boards, and will try the 90cr XHP-70 again. Just enjoying this one for now!!!
Excellent work. You ripped all the weaknesses out of the light and kept it's strengths. Well done.
I'll be copying much of what you did on my next 7G10.
Thanks ImA means alot coming from you and FP!! It is one of my favorites now! The reflector of the 7G10 is coated much better than most or any OP reflectors I have seen, way better than the SD75! The beam of the 7G10 is as close to perfection as I have seen! Truly a diamond in the rough! The only gripe I have is with the battery carrier springs , way too soft, but Iâll remedy that too!! Itâs a great driver to bad more arenât made using this, absolutely love the smooth ramping and simple 2 level UI, which is all you really need in a big light and could be easily tuned down by adding resistors.
Thanks again for your comments. I also noted the high quality reflective surfaces on my G9 and G10. They appear to be right on par with Fenix and Olight flagship lights, which can easily provide +20% or more lux over lesser reflectors of the same shape and size. Id say we all scored big-time for the price of these lights as mod hosts. Your explanations and pics make it very easy to replicate your work for almost anyone able to solder⊠so MAJOR kudos go to you for sharing this one with us!
As an aside, I also enjoyed reading about how you built a simple precision jig to slice the dome off your XHP70 mod. The pic looks like Cree performed the mod at their research center while ignoring the rest of us!! |( Damn you!!! :bigsmile: