I found out the price.. starts at £26k!!
🔋 Semi-Solid-State batteries revolution!
- Thread starter BikeBert
- Start date
I wonder these day if many "High Tech" companies are not selling products, but stock. I know of an EV company that leads the world in broken promises and false dreams, yet is very successful.
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earleb
New Member
People have been digging into Donut labs claims and it seems like it's supercapacitor hybrid rather than a solid state battery.
I think that’s set to change, but certainly I have some Turnigy Graphene RC batteries that are probably more accurately described as ‘graphene enhanced’ and do enjoy faster recharge times, less voltage droop as they discharge and higher energy density for the given pack size.
I could see those making it to a bicycle battery pack, not sure about solid state batteries though as how many of us really need to charge immediately following a ride to do it all again?
Perhaps bike hire firms would benefit, maybe even e-bike couriers, not sure it’s needed for everybody though unless there’s a proper weight benefit.
MountainBoy
Active member
Wow! For that price you could get a nice, low mileage Tesla Model 3 that's quicker (and has a heat pump and stereo), and a battery that's 75 kWh.
You have missed the point.
No super/hyper bike is cheap, whatever powers it.
The graphene "enhanced" are not graphene. They use a chopped carbon element in the chemistry, so they're not outright lying, but they're certainly misdirecting. It's in no way actual graphene, just a standard enhancement of lithium polymer chemistry that has been widely adopted, but a few companies have thrown their marketing spin on it.
Graphene is a 1 atom thick layer of carbon that has never been produced outside of a laboratory. It was originally hailed as the path forward to lighter, more compact batteries through more structured anodes.
Hell, you can buy car wax with "graphene" in it now. Same marketing shenanigans is happening with ss battery stuff now.
I did say that, to be fair!
Graphene batteries, from what I’m reading, are soon to become more widespread. There’s always a lag between concept and market, I think we’re still in that.
MountainBoy
Active member
You have missed the point.
I thought the point was that these leading edge batteries would be cheaper, faster, lighter, better. It looks to me as if the "holy grail" is still unobtanium.
I saw those reports and a video about Donut at CES 2026. Donut at CES were just being so evasive about this product, that is supposedly being delivered in production vehicles within the next 12 weeks.
This close to deliveries to the public, it's not a good look. They do realise that if it is delivered to the public in less than 3 months, someone is going to tear the battery apart, and let the cat out of the bag. So being so evasive this close to release, makes no sense, unless it doesn't stack up to the claims.
The only conclusion can be Vaporware to drive up investment. 400Wh/kg energy density from a super capacitor would be a massive stretch from a group of 22 people in 2 years.
Time will tell. But it appears more money grab than revolutionary product release.
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They are certainly not, beyond the marketing baloney "graphene" batteries.I did say that, to be fair!
Graphene batteries, from what I’m reading, are soon to become more widespread. There’s always a lag between concept and market, I think we’re still in that.
As mentioned, graphene has never been successfully produced outside of a research laboratory.
Yeah, its got BS written all over it.
All* "leading edge" technology is initially expensive and thus only finding its way into high value niche markets, taking a while to be scaled up at lower costs for other markets.
By far the most important question is whether new solid state battery technologies are now genuinely coming to market, or whether this is yet more 'vapourware'.
* There may be exceptions but none come immediately to mind.
MountainBoy
Active member
I can answer that question. It's vaporware.
There are many companies and organisations researching so-called solid state batteries and some will almost certainly have commercially viable products. But my guess is that they will continually develop these products and will not want to be first to market because that would open the floodgates and perhaps see other superior products released which would obsolete their product.
its on their website, the one i spec'd was about £30k
pagheca
Active member
the failure of one technology doesn’t automatically mean others won’t succeed. The real issue is that a battery with the performance being claimed would be a genuine game-changer, but to be commercially viable it needs to excel in three key dimensions: (1) energy density, (2) charging speed, and (3) cycle life. Many experts say you can usually optimize two of these, but not all three at once — and that’s before even considering safety, cost, and other constraints.
So, I’ll start believing the hype when someone can actually demonstrate strong results across at least these three fronts.
eMullet
Active member
Also, is this 400Wh/kg energy "density" by weight raw cell or final usable battery (including internal electronics, casing)? Totally 2 different things. And what about Wh/m3? Cotton candy has pretty good energy "density" by weight but not in volume.
We're talking about cells, so It's the raw cell energy density(gravimetric), not the whole battery pack. Final pack energy density will vary between different pack manufacturers.
I haven't seen any volumetric energy density specs of Donutlab cell....
Solid state will be amazing, but I dont see ebikes getting them (Mainstream at least) for another 3-4 years. Maybe even beyond that. Current battery tech keeps improving. I look at the capacity and weight for giant energypaks and bosch batteries from 3 years ago to now. weight has dropped a lot , smaller batteries. By the time solid state becomes viable, the tech of lithium will be that good will it actually offer anything above them? Its impossible to tell
Depends how much eMTB riders are prepared to pay to reduce weight.
Currently seems to be about £1 per gram (£1,000 per kg).
That measurement makes no sense. Depends on manufacturer etc. plus your taking total bike weight, not battery/motor weight. Lithium 800wh battery has dropped by over 1kg in 3 years. If it does again over the next 3 years, solid state becomes not worth the hassle/money
$1 or 1 Euro/ gram is just an old Weight Weenie formula to determine the basic value of weight loss mods.
Just because it hasn't aligned with other weight loss, such as recent battery tech, doesn't change that it's sort of the old standard that some people use to judge the relative value of money spent versus benefit gained.
Just because it hasn't aligned with other weight loss, such as recent battery tech, doesn't change that it's sort of the old standard that some people use to judge the relative value of money spent versus benefit gained.
The elephant in the room is the limited known deposits of lithium and the horrendous cost, environmental, economic and human, to mine it. Folk refer to the long term availability of oil and gas, but both far outlast supplies of lithium.
As opposed to the horrendous cost, environmental, economic and human, of extracting and refining oil?
The key difference between oil/gas and lithium for propulsion systems is that lithium is eminently recyclable.
Lithium is also one of the most abundant materials on earth and you shouldn’t confuse illegal or ‘artisanal’ extraction methods or mines with properly run commercial ones, they’re very different.
I’m also wondering what problem exactly solid state batteries are seeking to solve, from an e-bike perspective?
It’s got to be weight reduction I’d say, recharge times and cycle life are hardly issues for most e-bike owners/users, the main benefit would be lighter batteries for a given size or higher capacity ones for the same weight/size?
Whenever and in whatever these first become mainstream, I don’t think it will be bicycles.
MountainBoy
Active member
You forgot cost, which is the metric that matters most. Here's why:
Cost per kWh determines the volume the cells can be manufactured in, and it takes very high volumes of manufacture to reach acceptable costs. Cells made in low volumes can cost tens of thousands of dollars per kWh, instantly killing any potential market for those cells.
The most popular cell format for EMTBs was 18650 with 21700 taking over now, especially in higher end EMTBs. This is no coincidence. Tesla introduced the original Roadster in 2008 and followed up with the Model S, both of which used 18650 cylindrical cells, back in the day that people thought it was wrong to use cylindrical cells to power an electric car. The cars were very expensive and didn't have the range of cars today, mostly because the cells were so expensive. But as manufacturing volumes increased, cell prices fell dramatically. In 2017 Tesla co-developed the 21700 cell format with Panasonic and introduced it in the higher volume Model 3. This drove production volumes higher and costs fell further.
It's no coincidence that EMTB sales exploded after production volumes of 18650 (and later 21700) cells exploded due to their adoption in electric cars (an electric car has about 100 times more cells than an EMTB). Price determines volume and volume determines price. Manufacturing high quality cells in high volume is very difficult, it can take 6-12 years to perfect the manufacture and drive down the cost and this is after there are perfectly fine working prototypes of the cell you want to make.
We take for granted the relatively low cost of batteries these days but it's important to realize that this is only possible by the hard work of thousands of very talented engineers, supply chain specialists, advanced manufacturing experts, etc. and the investment of billions of dollars over a multi-year period. Nothing is easy, you don't just wake up one day and put decide to put a new cell into production and expect it to start selling next year. All this means it takes a long time to bring a new battery to the mass market at acceptable costs.
Toyota has been telling us they have a solid state battery ready to bring to the mass-market in two years. They have been telling us that for over 12 years! They dangle this carrot in front of us as a way of implying the current battery technology isn't good enough to replace gasoline cars. But the solid-state battery they have been promising for over 12 years never comes and they continue to sell 99% gasoline powered cars. Meanwhile, Tesla has sold over 9 million electric cars, and they do it very profitably. Evs are already better than a gas car at the same price point.
The requirements for an acceptable EMTB battery are more difficult than for a car because a car has sophisticated liquid-based battery thermal management systems that maintain the cells at optimal temperatures for fast charging and longevity. A car can heat or cool the battery at will. The original Nissan Leaf did not have a liquid based thermal management system and thus EVs developed an early reputation of not lasting very long, much like an EMTB battery that gets heavy use. Temperature and battery life is strongly linked but weight considerations have prevented EMTBs from having sophisticated thermal management systems that are effective.
All of the above are reasons why I'm highly skeptical of commercially viable solid state batteries from Donut. A party trick is not commercially viable. Because cost.
MountainBoy
Active member
It's cost. And that is only solved through volume.
So you are correct that EMTBs and electric motorcycles will not be the first mainstream use of solid state batteries. It's almost a given that the Donut e-motorcycles with solid state batteries will be sold in low volumes and at a huge loss. That is not sustainable, it's more of a party trick. I'm guessing the company sees the real profit (for the insiders at least) as coming from uninformed investors, not viable profits.
