P7 MAG 3D with KD driver and 3 D size

I'm going to give building a 3D P7 Mag a try.

I ordered 3 D-sized protected Li-ions from kaidomain and their $12 driver. Will this be sufficient to regulate 3 D sized Li-ions ? I've seem to have read some good and bad threads on this driver...

What sort of runtimes can expect on high vs med vs low ?

Also, does anyone know how i can get in touch with them ? I got an account activation link and was able to see my order, but when I tried again I havent been able to log in, and the help section requires a login too.

you should know that the KD driver overheats even with 2 Li ion cells.
if you have a proper heatsink on it then 8,4 volts are ok.

But 3 li ion cells will cook it. no change for that build :sigh:

you can try to contact KD via email....but accounts and order tracking did never work -.-

Hi,

the KD driver does not overheat. I use it in 2 Ultrafire Wf-1000:








I never had a problem with this driver although the pills look terrible. The advandage is: At about 7.3 Volt it has a low battary warning. Maybe some people had bad luck with this driver but overheating is not a general problem.

I guarantee that you will have MUCH better luck with the:

Shark Buck by the Sandwich Shoppe
https://www.candlepowerforums.com/threads/211599

or the

SSC P7 Buck Converter by Der Wichtel
https://www.candlepowerforums.com/threads/201981

Both are superior buck drivers specifically made for the P7 or parallel wired MC-E

Packesel said:

the KD driver does not overheat....

I never had a problem with this driver......

Maybe some people had bad luck with this driver but overheating is not a general problem.

Click to expand...

I would say you've had good luck.

There are multiple threads covering the overheating problems and other issues with this driver.

-Michael

Got to say go with Der Wichtel driver got two you can tune them to your forward voltage, VGQ , buy one you'll not regret it :twothumbs IMO cheers DocD

I too am going to say I have reservations about using 3 li-ion cells with the KD driver. Dont get me wrong its a great driver for the money, I run one on the KD 2 pack, and I heatsinked the driver to the wall of the light using thermal grease to help it stay cool. I can run my light for about 20 continuous minutes on high before the driver will kick to low. If you are going to use 3 cells you may have to sandwich the driver between a couple of very thick washers with some thermal grease or somthing to keep it cool enough. Anyway good luck

thanks for the info guys, i'll see what i can do with the kd driver, since its already in the mail and i'll upgrade to der wichtel after i get something put together and cant get it working decent with some additional heat sinking.

Any thoughts on what I can expect for runtime at the different levels given the source of 3 D li-ions?

i stumbled upon this forum and this modding scene, but ordered up a storm already. i've seen a lot other people mention the same, not surprising. this stuffs fun!

I think in "theory" (please someone correct me if I am wrong) an led that draws 3.7 volts and 2.8-3.0 amps run times could be loosely calculated like this. Each cell is rated at 5 amps(or 5000mah) and since you do not need more than the voltage than one cell puts out you can add the amperage and not the voltage. So 5+5+5=15 amp available divided by 3 amps needed (on high) is 5 hours. This is a very rough estimate though as it depends on weather or not the cells perform at rated capacity, also on the efficiency of the driver etc.

Another tip for calculating runtimes is this. When cells are combined in series ie like in your light +-+-+- for an incandescent light you would add the voltage together and not the amperage. You would have 11.1 volts and 5000mah, if your bulb draws 5 amps at 11.1 volts you will have one hours run time. However when cells are wired in paralell ie side by side +++--- (like if you put 3 cells side by side with all the Pos ends up) that would give only 3.7 volts but 15 amps so if your bulb still draws 5 amp (which it wouldn't) you would get 3 hours run time. The reason the math for your light is differnt than this is because of the driver.

There are more exact ways to do this (converting to amp hours) but I wanted to try and keep it simple for now. Hope this helps.

+1 for the driver from 'Der Wichtel' :thumbsup:

I have two of them and they both work perfectly never had any problems with them and they don't get warm even while running continuously for a long time.

rayman

I have very bad experience with KD driver (in Mag 2D P7 6AA). Thermal protection kicks in after less then one minute!

@ phantom23

Was this without heatsinking the driver?

Glued to heatsink by heatconducting glue. The only change is it cools faster (I can switch to high mode after shorter time).

From what I hear, the heatsink actually accelerates the problem, since the LED heats up the driverboard. Better to heatsink to flashlight body!

Scattergun said:

From what I hear, the heatsink actually accelerates the problem, since the LED heats up the driverboard.

Click to expand...

After one minute?! No way!

Scattergun said:

From what I hear, the heatsink actually accelerates the problem, since the LED heats up the driverboard. Better to heatsink to flashlight body!

Click to expand...

+1 for heatsinking on the body, as close to the switch as possible.

i got the KD D-sized batteries in the mail recently -- i didnt realize they wouldnt all fit, they measure out to some cover some of the thread.

anyone know of a way to make this fit ? or is there some way to extend the length of my mag ?

phantom23 said:

I have very bad experience with KD driver (in Mag 2D P7 6AA). Thermal protection kicks in after less then one minute!

Click to expand...

+1
Mine makes it just over 1 min., but not by much! Heatsinked to the battery tube, waiting for the updated BuckShark to solve that problem, or a new smaller DerWitchel.

I really doubt the KD will work with 3 Li-Ion, if my 2 Li-Ion are fully charged to 4.2 ea. the protection kicks in even faster, as the cells settle down around 3.7 ea, it takes longer for the protection to kick in. Sounds like it doesn't like anything >8v.

Here is your extension tubes:
https://www.candlepowerforums.com/threads/206419

thanks, i'll check out those extensions.

what if i run the batteries in parallel, will the kd driver be able to manage that ok ?

ironmang said:

thanks, i'll check out those extensions.

what if i run the batteries in parallel, will the kd driver be able to manage that ok ?

Click to expand...

The driver probably would not work because I think it requires a minimum of 5.5 volts to operate and if you ran them in parallel it would only produce 3.7-4.2 volts max.