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World's 1st Sodium-Ion Flashlight: Engineered for Winter (kickstarter) (for info only, this looks ridiculous tbh) (www.kickstarter.com)

submitted 1 week ago by solrize@lemmy.world to c/flashlight@lemmy.world

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Fwiw Molicel INR 21700's are rated for discharge down to -40C (pdf) though charging only down to 0C. I don't see a need for a sodium ion flashlight just yet, but I'm posting anyway since I guess it's news despite being stupid.

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[–] dual_sport_dork@lemmy.world 7 points 1 week ago (2 children)

Sometimes baby steps are how we make progress. In the field of consumer gadgetry, said progress is often driven forward by selling objectively silly things to nerds with disposable income. Remember, in fact, how back in the late 90s and very early 2000s there were still Very Intellectual people on forums going on about how LED flashlights were just a distraction. A mere expensive curiosity for yuppies who didn't know any better, they'll never be able to achieve decent price/brightness/color, and obviously everyone knows that high powered little quartz halogen bulbs are where it's at for anyone who wants a flashlight with a truly studly output. They're what the cops use, after all. Clowns who spent a lot of money on LED lights only wound up with novelty gimmicks like this.

Uh-huh. That table turned pretty quickly.

Up until now, lots of people have been saying, "Yeah, yeah. Wake me up when sodium ion is an actual viable product." Myself included, probably. Well, here we are. (Maybe.)

This thing isn't a form factor I'm interested in or have much of a use case for, but since current sodium ion cells have a significantly lower capacity per volume than lithium ion a big ol' baseball bat of a flashlight is probably the ideal proportion for this kind of thing.

[–] Onomatopoeia@lemmy.cafe 4 points 1 week ago* (last edited 1 week ago) (1 children)

I'm kind of liking the form factor.

Having grown up with mag lite being the new consumer thing that actually worked, there's something to having a beefy light in your hand.

[–] solrize@lemmy.world 2 points 4 days ago* (last edited 4 days ago)

Wurkkos TS27 has an LFP battery and is beefy and advertised as a duty light, and it seems nice except then it has this silly RGB ring light that turns it into a fidget toy. I lost interest because of that. YMMV. :)

https://wurkkos.com/products/ts27

Added: I just looked over the kickstarter page for this light. The battery looks to be 10,000mAH nominal, size 32140 which is 4.7x the volume of a 21700. Voltage is 3.0 nominal but looking at the discharge curve at -20C it looks about 2.5V on average, so 25 WH. Not that much better than a 5000mAH 3.6V 21700 (18WH). The sodium is somewhat worse but still viable at -40C and I guess it might be beating lithium by then too, plus it has the ability to accept charging at -40C. I don't see super-cold charging as very important for a flashlight (if you're able to charge your light you can probably keep it at least a little bit warm), though super cold operation can be helpful.

Also, this is a 2500 lumen light which is a far cry from the old Maglights that were perfectly usable. The classic 2AA minimag was around 5 lumens over most of its runtime, the huge 6D was something like 36 lumens, and the nicad powered Magcharger was about 180 lumens. Surely for changing a fuse, a low powered headlamp is preferable to a huge handheld ;).

[–] solrize@lemmy.world 2 points 1 week ago

Sodium batteries are mostly of interest for grid storage or maybe stationary home batteries once they get cheap enough. They are sort of marginal for EV's but might find a place in some cold weather ones. Having them in a few weird flashlights isn't going to help ramp up manufacturing volume compared to that. The real demand will come from power utilities buying gigawatts at a time, not a few flashlight nerds.

I remember the Eternalight and it went through a few nicer incarnations over time The designer was a regular on Candlepower Forums. IDK if the company still exists. The product was cool in some ways. IIRC it uses 5mm leds. The first production flashlight with a Luxeon was the Arc LS and I had two of them. I think the semi-custom McLux TK may have been earlier but my memory by now is hazy. I still have mine. Sodium batteries are different. Aside from the very niche advantage in cold weather charging, they are worse in every way than lithium. The main feature that makes them interesting is potentially lower cost per KWH in the long run. That's great if you want a 100KWH off-grid battery for home, and maybe it can find its way into economy EV's. But nerdy flashlights, nah, battery costs are not much of an issue already. The bigger light and fancier charging and regulation circuitry negate any advantage. We could already use LFP batteries if we wanted to, but we almost never do.

[–] JustEnoughDucks@feddit.nl 5 points 1 week ago (1 children)

I would like to know what charging chip they are using for charging it, because there aren't any mass produced sodium ion charging chips that I have been able to find for my own projects and it 100% is an off the shelf part.

[–] solrize@lemmy.world 1 points 4 days ago* (last edited 4 days ago) (1 children)

It wouldn't surprise me if there's not yet any sodium charging chip for small consumer electronics like this. I haven't heard of a sodium powered flashlght, phone, or anything like that before. The only sodium consumer device I know of right now is a Bluetti power station which has 900WH: https://www.bluettipower.com/products/sodium-ion-battery-pioneer-na

It got some attention at its anouncement but tbh it's 10lb heavier and $300 more expensive than the 1024WH lithium version (Elite 100v2). So it's for early adopters only.

If you want to charge a small sodium cell, you can probably program an MCU to deliver the right charge profile, along with a few small external parts. That's how Apple phones worked at least in the past. They saved a fraction of a penny by just incorporating some extra logic and code in their big ASIC instead of having a separate charging chip. It's kind of interesting that the charger was programmed in Forth, on a special Forth processor (b16-small) that they cooked into a hardware macro: https://bernd-paysan.de/b16.html . They hired Bernd (the b16 designer) to write the code and it was pretty intricate because of the cpu's limitations. I don't think I'd have used that approach ;).

[–] JustEnoughDucks@feddit.nl 2 points 4 days ago

I know of one chip that is a sodium ion charger but I think it is only available in China and not in the west since the tech is picking up more speed there.

I guess you technically can use a Lithium ion charging chip with a programmable charge voltage like the BQ25300 but the problem is that almost every chip with a programmable charging voltage also has an under voltage shutoff to prevent deep Li-Ion discharge (usually 3, 2.5, or 2V), but that also means that you can only use like 50-80% of the already limited capacity.

One of my next projects is using GreenPak programmable signal matrix (like a very mini FPGA) to make a sodium charging chip I can put in projects.

[–] IMALlama@lemmy.world 1 points 1 week ago (1 children)

With a zoomie?!

The claim of the battery not minding getting fully discharged is nice though.

[–] solrize@lemmy.world 2 points 4 days ago

I've generally heard that it's ok to discharge LFP batteries to 0%. You just shouldn't store them that way (or at 100%) for long periods. Keep in mind that LFP has maybe half the energy density of the highest density NMC batteries, and sodium has maybe half that of LFP. Sodium really doesn't sound that good batteries for portable devices.