Emisar D4S review

Yes…that purple!

There have been some excellent lights recently released in the 26650 format - Thrunite, Lumintop, and now Emisar. I’m glad because I have lots of these cells, and it is a comfortable size for a hand grip. Too bad none of the big four battery cell companies are making these. 21700 may become the standard eventually, but probably still a few years off.

Sure I want one!
Hope Hank will sell the aux led pcb separately. I possibly buy 3-4 and make different led colors or multicolor boards to swap them as I want.

What are the benefit of using 21700 on the emisar d4s??

what a cool light, thanks for the review. can’t wait for it to show up in the store.

Yeah… the D4S’s blue light isn’t going to give anyone cancer.

Light, in general, tends to make people feel more awake. Particularly blue shades, but blue is also a component of white. The D4S’s 4000+ lumens of white light (of which probably 1000 is blue) are going to have a much bigger effect than half a lumen of glowy blue from the aux LEDs. Or on the low mode, it’s like 0.001 lumens. It’s completely negligible. The brightness is more important than the color. Even a 2700K incandescent bulb emits more blue light than these little aux LEDs.

Most people have at least some wakefulness response to light, but not all. Out of every 20,000 people, about 3 don’t have this response. Of those 3, statistically, 2 are actually blind. And I’m the other one. Because I see just fine, but my iPRGCs don’t work.

If you want a D4S to cause cancer, you’ll have to eat the battery or shine it at your skin point-blank on turbo, every month, repeatedly causing burns on the same place… and I’m not sure if even those would do the trick. But a tiny trickle of blue light is harmless.

The magnet is optional.

Well, the power you can push in the case of the D4S.

The highest current 21700 can push 35-40A. So, for people like Dale, you can put something like SST40s/Luxeon Vs/XPL2s and push even more power through for like 15 seconds.

Tesla designed the 21-70 to be optimal for their very specific requirements.

Which may or may not align with what’s optimal for torches or other consumer applications.

Too fat to be applicable to e.g. laptop cells or other stuff. Laptops in particular are going slim and light, with pouch cells.

As is every other EV manufacturer AFAIK. In the next two years the mainstream manufacturers will be launching real world affordable EVs, and no, they won’t be using a big pile of steel cased 71-20s, but big bespoke bagged cells, which pack far better. And can be thermally managed far better.

I sense some bandwagon jumping by those who blindly follow Tesla’s direction. They have built their Gigafactory(ies) based on a certain (bought in) manufacturing process which bought them fast time to market, and are pretty much committed down that path, but history will decide whether that is the best direction for the future. Or whether Tesla make it.

No other mainstream auto manufacturer seems to think so.

Watch this space.

What are you meaning about better thermal management?

It is always easier to cool off smaller cells rather than bigger cells, and battery packs using smaller cells are more reliable.

Yay for the strong magnet! Tail light magnets are never strong enough for me and I always have to add an extra one. Nice light!

TK, thanks for taking the time to show us how this D4S will become :wink:
I’ll wait for the final specs to be disclosed, but what was advanced make me like this light! It will be my first in 26650 format, so I’m curious about it!

BTW, those changes on the UI seem nice and, in some way, more practical than on the D4!
Let’s seen when it finally comes to public :sunglasses:

Not emptyquoting.

This looks like it is taking advantage of your Aux LED pin 3 feature of Anduril?

WOW :heart_eyes: :+1:

Well done Hank! I can’t wait to get my hands on one of those bad boys.

  • Aux LED’s look awesome! :laughing: I really like the blue. Red might be fun as well. A few options would be cool.
  • I’ve read the magnet is “optional,” does that mean its removable from the tailcap?
  • 26650 battery config is great. Is there going to be a short tube offered for 23650?

Thanks TK for the review!

Yourrid, pretty sure TK said she got two tailcaps, one with and one without the magnet. :wink:

One thing I like about the 26650 format is the extra room it gives to spread out the LEDs on the MBPCB.

Although, I have never owned an 18650-based triple or quad, I have always been suspicious that the optics on some of those lights are covered a wee bit by the bezel. In practice, I doubt it makes much difference in output, but, hey, every little bit counts.

Thanks for a great review.

Very cool light! The larger mass should help a lot with temp regulation and extend turbo for quite a bit. I hope to see a 21700 tube for it.

Well there goes the flashlight budget again, gotta have one of these now.

Tagging to keep track of when they are going to go on sale…