Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Alan Stewart]

Stark and Eve Energy have introduced the 26120 cylindrical battery cell, design specifically for motorcycle battery packs. Aluminum instead of steel to improve cooling and save weight.

https://enduro21.com/en/news/industry-news/stark-future-partners-with-eve-energy-for-next-generation-battery-cells

[princec]

Still peculiar why they're sticking to cylindrical format for motorcycles at all, when it's got such a lot of wasted space in a use-case so well understood to have absolute limits to weight and volume.

Cas

[Specter]

princ, the only reason i could see would be IF you wanted liquid cooling, you could flush it between the rows of batteries and get some decent surface area on each case for heat removal, although still a bit wasteful.

aluminum weighs less than steel but has a plethora of other issues.  it picks up heat pretty quick but gets rid of it a bit slower from my own experiences with it.  The weight, might save 5 lbs or so?  Steel is cheaper, and sturdier, so how much more would the aluminum cost? Granted its in a protected casing so may not need as much protection from outside environment, but still. the overall gain you might see, is it worth the premium price you WILL pay?

time will tell

Aaron

[Fran K]

Here is a quote from the article " Stark aims to integrate the new format into its next-generation on-road motorcycle".  That does not at least to me lead to "Stark and Eve Energy have introduced the 26120 cylindrical battery cell" I guess it depends on how one views the word introduce.  I was thinking how does 2170 100 in series 4 in parallel fit with a combination of these 120mm long and 26mm diameter. 


Curious what their on-road offerings are and how much is going to be shared with Royal Enfield.  They got off to a rough start but after folks getting new batteries and motor gearbox assemblies, they seem satisfied.

[T.S. Zarathustra]

"Stark Future has developed a new 26120 cylindrical battery cell format specifically for high-performance electric motorcycles, designed to overcome limitations of automotive-derived cells like the 21700.
Measuring 26 mm in diameter and 120 mm in length, this cell exploits the narrower width of motorcycle chassis for improved space efficiency and thermal performance.

Key features of the 26120 cell include:

330 Wh/kg energy density (prototype tested).
10-minute ultra-fast charging capability.
Aluminum cell enclosure for better thermal conductivity and reduced weight compared to steel cans.
Optimized for higher packing density, lower system mass, and improved heat dissipation in motorcycle applications.
The cell is being mass-produced starting in 2026 through a strategic partnership with EVE Energy, a leading global battery manufacturer and top cylindrical cell supplier in China.
 Stark Future plans to integrate the 26120 cells into its upcoming on-road electric motorcycle platforms, building on the performance proven in its VARG motocross model.

AI-generated answer. Please verify critical facts."

This makes sense. The cells are becoming ever larger, which uses the space inside the cell more efficiently. We used to be stuck with smaller cells because it was difficult to get large enough materials in consistent quality, and it was less waste/expense to have defect in smaller cells. Technology to build larger cells and quality of materials is constantly getting better.
Larger cells lead to fewer connections, which simplifies battery-pack builds and makes them less likely to fail.
Let's say they come with plugs or screws on the ends. That would make replacement of single cells easy. (Say that it's bad to replace a single cell. Yes, yes. Let the hate flow through you. ) Replacing a single cell is bad if there is no BMS. If you have BMS it will protect every cell in the whole pack. Preventing any issues. Aluminium makes the cells lighter and better at cooling. It is also better at conducting electricity. The minus in a cylindrical cell is conducted through the casing. Aluminium (instead of copper) wires become more viable option, possibly reducing cost.
Pouch cells are easier to pack but need to be encased. Cylindrical cells are better protected. You could space them few millimeters apart and have air flow through the pack. You could even make the cells a visual part of the battery design.

This cell is slightly thinner and longer than the two D cell that used to be popular in pocket lights, and lasted for a day. My 18650 single cell pocket light can stay lit for 1000 hours (42 days) on a single charge and lowest light output. If I got pocket light for this cell it could probably stay lit for 3-4 months on a single charge. If it was only used it during dark hours and turned off during sleep it could light an off grid cabin throughout the winter on a single charge.

[princec]

Something I remember from a while back when Tesla were talking about battery pack design ... the gaps between the cylindrical cells weren't an awful lot of use for cooling - almost all of the heat is concentrated at the battery terminals at the end of the cylinder, so you need a design optimised for locally cooling that part.

Cas

[Specter]

that makes sense cas, thats where the connections are and where the current ultimately concentrates at to flow thru.
maybe they can make the battery terminals out of peltier junctions so that way the batteries can be self cooling, and self heating in the winter


you wouldn't want airflow thru the battery either really, that brings contaminants from the outside in, and worse, condensation-humidity.

Aaron

[princec]

I did wonder that it might be possible to make a reasonably good temperature regulation system by just squirting some form of dielectric non-flammable liquid in at the top of the battery through a load of holes, letting it trickle down through the gaps, collected at the bottom and then pumped back up to the top via a radiator.

Cas

[Specter]

but then each individual cell must be absolutely airtight water tight, and the chemical you are squirting in, can't interfere with them, cause them to chemically alter / corrode, OR conduct electric either.   now you need pumps, the radiator, more room and weight.   
no it's not an easy task to throw liquid cooling in

aaron

[princec]

You would hope they were already absolutely impermeable already...
several non-flammable dielectric liquids already exist for this exact purpose, can't help but thinking it's not rocket science to get this implemented.

Cas

[T.S. Zarathustra]

Something I remember from a while back when Tesla were talking about battery pack design ... the gaps between the cylindrical cells weren't an awful lot of use for cooling - almost all of the heat is concentrated at the battery terminals at the end of the cylinder, so you need a design optimised for locally cooling that part.

Cas

Good point. Aluminium conducts heat better than steel. I believe the cells Tesla uses; Panasonic, LG, CATL, etc. all have steel casing.

[Specter]

but on the other hand, if something does go wrong and a cell gives up the magic smoke, aluminum may help propagate a thermal runaway much quicker, as it'll push that heat right into the next cell, possibly setting it off as well, where steel might slow heat progression down enough to stop a chain reaction.    aluminum is also a bit reactive, especially in negative voltage territories.  it'd be better for the positive terminal, and batteries where the can is a lead, typically is the negative terminal.

then again, in pouch cells, it works ok for what it does, and the weight reduction, of course. while super critical on a bike, in a car, not so much

looking forward to seeing how they behave.

aaron

[T.S. Zarathustra]

but on the other hand, if something does go wrong and a cell gives up the magic smoke, aluminum may help propagate a thermal runaway much quicker, as it'll push that heat right into the next cell, possibly setting it off as well, where steel might slow heat progression down enough to stop a chain reaction.    aluminum is also a bit reactive, especially in negative voltage territories.  it'd be better for the positive terminal, and batteries where the can is a lead, typically is the negative terminal.

then again, in pouch cells, it works ok for what it does, and the weight reduction, of course. while super critical on a bike, in a car, not so much

looking forward to seeing how they behave.

aaron

Wouldn't any possible thermal runaway propagation be slower in Aluminium cells than in pouch cells, that only have thin plastic separating them.

[princec]

It should probably be reasonably clear by now that lithium's days are numbered anyway, at least in its more dangerous incarnations. Sodium is in the ascendant, solid state's pretty much arriving shortly, etc. and I suspect that there's a bit of deliberate dithering at the moment while the manufacturers of the things wot we love wait to see what wins out.

Cas

[Specter]

show me a sodium battery that hit the market and is doing fine, same with solid state.    cute videos at aes porn fests do not equate to real world items.  one day very soon we'll have teleportation too and not have to worry about this either.

aaron