triple stack 7135's

I have been looking around a bit and I find some people mention triple stacking 7135’s and i have even seen a pic of one that was done but I haven’t seen any one describing the best way to do it. does any one know of a post or sticky that explains the best way to do this. I would hate to not take advantage of the hard learned lessons of others. any input would be appreciated. i did my first double stack which seemed like it went fairly smoothly, I just followed old lumen’s and rmm’s how to videos. they made it very clear. I was very thankful for the time they took to make and post these. and my condolences to Mrs old lumens, all i saw was his one instructional video but could tell just from that what a genuine and nice fellow he was. I was sorry to find out of his recent passing. thanks ahead of time for any responses.


Taking a guess here as I don’t stack chips. I stacked a few “doubles” successfully, but no triples. What I would do is I either avoid bending the pins on the middle layer, or I’d bend them only a little, and then bend the top layer even more.

I think stacking is kind of out of fashion now days, FET drivers appear to have taken over, and that’s fine by me as I hate stacking. Been there, done that, ain’t going back!

theoretically why not, as many as you want. as long as you are not running teh led with 4 nimh, or 2 cr123, you can stack chips, however if you using any of the 2 mentioned power sources, you may run into heat issues, even without stacking chips shut off on hi temp protection they have built in, having 2 extra “heaters” on top wont help. not to mention stacking 3 may make it thick enough not to fit in some pills, in case with 8 chip board, if you triple bottom chips, you’ll have them higher than the spring. As mentioned above, fet driver can do same with less parts\heat issues, in smaller package.

thank you for the advice. I’ll try that. I like fet drivers but I like regulation even better. the dr. jones fet+ 7135 driver is really nice but I want the regulation to go all the way up to 6 amps or so. the direct drive is nice for turbo and the standard 3 amps regulated is nice too, but my preference is to have as high a regulated current as makes sense with xp-l2. and of course you can’t beat the stock lucid drive firmware. after some thought though I think I can just double stack 6 on bottom battery side and 2 more doubles on the led side. that should do it. thanks again for your response.

I’ve done it by glueing them into a stack and weaving fine guage wire around the pins. Recently, a member found that you can sand them down much thinner which should make stacking easier as well as more compact.

I actually thought about sanding them down but then I wasn’t sure if this would destroy them or not. any links to this other members post?

obviously too much sanding will, but the question is where is the line?

1 Thank

Shorten your 7135s for space-constrained mods!

ahhh. thank you, everyone is so helpful,:slight_smile:

A slave board might be an option to consider, providing your light can fit one behind the driver.

is there a way to test if the 7135’s are still good?

as they run all in parallel its imposible to find the defective one without desoldering em one by one

best is to test the driver after you stacked a few with a test setup on your bench
also using a DMM to check for shorts when soldering

what about if you have taken them back off, how would you test them by themselves? do they have a certain resistance to look for?

Connect a battery or other power supply
Solder an LED with heat sink to driver
Emulate switch pushing the cables together

There’s an Oshpark projects test board you can use to test individual
loose chips.

I had one chip on a driver which made all modes less bright by using too much current on the PWM pin most likely
on 100% pwm the light pulled 2.8A as expected, but it messed up the low to medium modes

Moonlight didnt even light up with it soldered, not sure if a test board can eliminate this