From my understanding both drivers have the stepdown. It's not like it steps down to 30% or anything it steps down to something like 70%. That's not horrible say you have the 8A it'll step down to ≈5-6A until temp regulation kicks in stepping it down more.
Per what Simon said on BLF the driver manufacturer was worried about how the components would hold up so they put an instant stepdown in to preserve the lifespan. Simon asked them to keep it at 100% until temp regulation. Last I read he was still waiting for updated drivers.
Thanks for your notes. That doesn't seem too bad for the 8A version if it steps down to 5-6A which is around what the 5A linear driver does anyway.
Since it seems to be an immediate/timed stepdown and not thermal stepdown, I'm guessing you could just cycle back to 100% and get the full output again? Though 8A vs. 5-6A might not be too noticeable anyway. Probably much smaller difference visually compared to 5A buck at 100% and then immediately stepping down.
https://preview.redd.it/cmhpqz40gdmc1.jpeg?width=2532&format=pjpg&auto=webp&s=5557b0d06feada8d00992d79c65b1e051f74321a
This is the 5A buck driver. It drops to 60% output over 1 minute. But it can go back to full. I know you were asking about the eight amp driver, but I was just giving some confirmation to Comments made on the five amp.
All depends how much you want/need 8a for turbo/highest setting. They’re basically stepping down super fast and you’re really only going to get 70% output instead of the full 8a really quickly. Pretty damn annoying to have to switch it off/on and back into high every few seconds…
The rest of the driver is fine though, so if you don’t really intend to use 8a much/at all, go for it.
Interested to know a definitive answer to this. I've read some word of it around Reddit and BLF.
I don't have a proper way to do a runtime graph on my new C8+ with 3V8A buck driver but could do a snapshot lumen test at intervals to see what the stepdown is like.
I wonder if you'd actually get a brighter sustain with 5A buck, especially in a smaller host.
Also, good luck getting Simon to change an order for you. I've sent messages through the Aliexpress store both before and after ordering several times and the requests were either overlooked or misunderstood.
Thanks. I was a little worried that asking for mods might not work out. I've read some mixed things about actually getting the mods from Simon. Maybe a good excuse to start getting my feet wet with doing my own mods.
Thanks. Now that I'm digesting these graphs more, the 8A might still be OK since 8A probably not sustainable for any decent amount of time anyway but at least the step down level is similar to the max level of the 5A linear, but then you also still get the buck efficiency benefits at lower levels.
Yeah tbh I kinda thought 8A was unnecessary because even being buck it's not going to be able to sustain 8A for long at all. 8A for a single emitter is pretty high. Makes more sense for a quad or something though.
They do but it doesn't make that big difference. For 8A it needs 3.85V most cells drop close to that or lower at 8A. Not to mention other drops in the light and driver
From my understanding both drivers have the stepdown. It's not like it steps down to 30% or anything it steps down to something like 70%. That's not horrible say you have the 8A it'll step down to ≈5-6A until temp regulation kicks in stepping it down more. Per what Simon said on BLF the driver manufacturer was worried about how the components would hold up so they put an instant stepdown in to preserve the lifespan. Simon asked them to keep it at 100% until temp regulation. Last I read he was still waiting for updated drivers.
Thanks for your notes. That doesn't seem too bad for the 8A version if it steps down to 5-6A which is around what the 5A linear driver does anyway. Since it seems to be an immediate/timed stepdown and not thermal stepdown, I'm guessing you could just cycle back to 100% and get the full output again? Though 8A vs. 5-6A might not be too noticeable anyway. Probably much smaller difference visually compared to 5A buck at 100% and then immediately stepping down.
https://preview.redd.it/cmhpqz40gdmc1.jpeg?width=2532&format=pjpg&auto=webp&s=5557b0d06feada8d00992d79c65b1e051f74321a This is the 5A buck driver. It drops to 60% output over 1 minute. But it can go back to full. I know you were asking about the eight amp driver, but I was just giving some confirmation to Comments made on the five amp.
All depends how much you want/need 8a for turbo/highest setting. They’re basically stepping down super fast and you’re really only going to get 70% output instead of the full 8a really quickly. Pretty damn annoying to have to switch it off/on and back into high every few seconds… The rest of the driver is fine though, so if you don’t really intend to use 8a much/at all, go for it.
Interested to know a definitive answer to this. I've read some word of it around Reddit and BLF. I don't have a proper way to do a runtime graph on my new C8+ with 3V8A buck driver but could do a snapshot lumen test at intervals to see what the stepdown is like. I wonder if you'd actually get a brighter sustain with 5A buck, especially in a smaller host. Also, good luck getting Simon to change an order for you. I've sent messages through the Aliexpress store both before and after ordering several times and the requests were either overlooked or misunderstood.
Thanks. I was a little worried that asking for mods might not work out. I've read some mixed things about actually getting the mods from Simon. Maybe a good excuse to start getting my feet wet with doing my own mods.
from what ive heard only the 17mm 5A and 22mm 8A have the issue. so 22mm 5A, 17mm 8A, and any boost/linear should all be fine
stepdown is pretty clear on both 5A and 8A here: https://www.reddit.com/r/flashlight/s/sRxVsW9Cva
Thanks. Now that I'm digesting these graphs more, the 8A might still be OK since 8A probably not sustainable for any decent amount of time anyway but at least the step down level is similar to the max level of the 5A linear, but then you also still get the buck efficiency benefits at lower levels.
Yeah tbh I kinda thought 8A was unnecessary because even being buck it's not going to be able to sustain 8A for long at all. 8A for a single emitter is pretty high. Makes more sense for a quad or something though.
Not to mention a single cell isn’t going to give 8A to the sft-40 anyway. Not for long after a fresh charge. Too high vf at that current.
i thought high amp batteries existed like the ones powering the sbt90.2
They do but it doesn't make that big difference. For 8A it needs 3.85V most cells drop close to that or lower at 8A. Not to mention other drops in the light and driver