Tesla 4680 batteries...

[The Dude]

Is it just me, or am I the only one anxiously awaiting the consumer availability of the Tesla 4680 battery in order to redo the battery packs a few years from now.

 

https://bit.ly/32WnJsQ

[RagingGrandpa]

+16% energy density. (From improvements to the NMC design; not a direct result of the cell size.)

It means a 1845wh MSuper could weigh the same as today's 1600wh MSuper. Not game-changing for EUC...

Larger cans are more difficult to arrange inside a compact EUC, and have worse heat dissipation.

(Bring us a new chemistry, world!)

Edited September 23, 2020 by RagingGrandpa

[Murdomeek]

These also will probably not be available to us normies to purchase individual cells until 2-3 years later.  And they'd be marked up too

[mhpr262]

It may not be such a great idea to use those in an EUC. Tesla typically removes as many safety features as possible from their specially manufactured batteries to bring down the cost and then relies on very sophisticated battery management systems in the battery pack to keep everything healthy. If you dont have those management systems the cells may be not safe for use.

[Philip W]

I am quite excited for the new batteries, but this new one has too low voltage to be used as the main battery.

The reason they can use 60v, 84v and 100v battery pack is that the 18650 batteries are small so they can build long series of battery packs. For the new 4680, the only use for EUC is probably only as backpack batteries.

[shellac]

Or you can run the wheel at a lower voltage but a higher current, like the Ninebot Z10 does

[Murdomeek]

 

On 9/27/2020 at 9:55 AM, Philip W said:

I am quite excited for the new batteries, but this new one has too low voltage to be used as the main battery.

The reason they can use 60v, 84v and 100v battery pack is that the 18650 batteries are small so they can build long series of battery packs. For the new 4680, the only use for EUC is probably only as backpack batteries.

You can probably fit 20 or 24 cells in there depending on the wheel (84/100v)

 

On 9/27/2020 at 11:47 AM, shellac said:

Or you can run the wheel at a lower voltage but a higher current, like the Ninebot Z10 does

You'd need a ESC and motor (kv) that's designed for that.  You'd need to swap it out with another wheel's motor/esc or have a custom one made

[UniMe]

I have been reading about these batteries, the environmental and manufacturing costs savings (50% reduction in cost) are stunning. Zero cobalt to start... they also have higher density and faster discharge rates -- it leads me to think that they may overcome much of the overpower risks with current EUCs. There are many others here who know more, but it makes sense to me that a fast discharging battery would prevent overlean issues.

I believe these batteries are the final step needed to bring down EV costs and to finally decimate the gas burning vehicle market. It looks like 18 months before Tesla is building cars with them, which is spot on with my timeline for doing the swap to an EV.

The increased energy density will also transform the electric motorcycle industry which currently faces a challenging choke point where bikes have crap range but can't carry any more weight in batteries.

Edited November 9, 2020 by UniMe

[mhpr262]

On 11/9/2020 at 7:20 AM, UniMe said:

I have been reading about these batteries, the environmental and manufacturing costs savings (50% reduction in cost) are stunning. Zero cobalt to start... they also have higher density and faster discharge rates -- it leads me to think that they may overcome much of the overpower risks with current EUCs. There are many others here who know more, but it makes sense to me that a fast discharging battery would prevent overlean issues.

I believe these batteries are the final step needed to bring down EV costs and to finally decimate the gas burning vehicle market. It looks like 18 months before Tesla is building cars with them, which is spot on with my timeline for doing the swap to an EV.

The increased energy density will also transform the electric motorcycle industry which currently faces a challenging choke point where bikes have crap range but can't carry any more weight in batteries.

Yes, the tabless design massively reduces internal resistance and increases the discharge rate. Tesla says "6x power" so I wouldnt be surprised if one of those puppies could deliver 90A continuously and possibly twice that for a few seconds.

[RayRay]

Re: 4680's

On 10/14/2021 at 8:45 AM, Paul A said:

the larger 4680 has nearly 5.5 times the volume, simply due to larger dimensions

Imagine fitting 30/60/120... in an euc. (They fat!)

 

(Multiples of 30 because people kept bringing up 4680's in thread about 126V...)

Edited October 15, 2021 by RayRay

[alcatraz]

46mm thick cells won't fit in most eucs I believe. Bummer.

It would be cool if cells came with a compact connector like screw on or something smarter. It would be cool to just replace a cell without having to spotweld it.

Edited October 19, 2021 by alcatraz

[Menace]

1 hour ago, alcatraz said:

46mm thick cells won't fit in most eucs I believe. Bummer.

If the companies wanted to they could easily use them. They could go above the wheel or on the side. The sides don't have to be completely flat, they would only have to be 1 or 2 cm wider on each side (compared to 21700 packs), and it could be slimmer where your legs go (and put controller and other components there). Its definitely possible.

[Paul A]

Comparative volumes.

Cylinder volume: V = π r² h

 

Volume of 18650   

≈ 16.54049 cm³

 

6 batteries:  6 x 16.54049 ≈ 99.2 cm³

 

 

Volume of 4680

≈ 132.9522 cm³

 

The tab less innovation is the breakthrough.

Simpler, cheaper production, less metal casing required, lessened risk of internal short circuiting from imperfect welding/burrs.

Less resistance, less hot spots, more even utilization of active materials coating electrodes, more even current distribution.

Musk has ambitions to develop batteries with energy densities higher than 400 Wh/kg to enable electric commercial flight,

 

 

[alcatraz]

52 minutes ago, Menace said:

If the companies wanted to they could easily use them. They could go above the wheel or on the side. The sides don't have to be completely flat, they would only have to be 1 or 2 cm wider on each side (compared to 21700 packs), and it could be slimmer where your legs go (and put controller and other components there). Its definitely possible.

You're right. I meant for retrofitting older eheels.

[InfiniteWheelie]

We started with 18650 cells then Tesla developed the 2170 cell which eventually became available through other battery manufactures, and has now moved it's way into the majority of wheels. Tesla's newest cell is the 4680 which is about 5 times bigger, and like the 2170 will be made by other companies too. I just want to point out that although they're not available yet, they're actually going to be perfectly suited to ewheels.

Take the Monster Pro or Commander for example. They use 2170 sized cells which are divided into 4 packs. There are 192 cells, so 48 per pack. The packs are 2 layers of cells deep, with each layer being 24 cells in series. This means each pack is 2 parallel (8 parallel total).

Using 4680 cells we can create a pack with only 48 cells total (12 per pack). If you placed the cells in a grid 6 high x 2 wide (cells laying horizontally), the pack would be only a tiny bit bigger in each dimension. The packs sharing a side would then be connected in series for 24 cells (100v). This would give each half of the wheel a 1 parallel arrangement (2 parallel total). With 48 cells at 92.5 wh each, that's a total of 4440 wh.

These cells are basically the perfect size for ewheels, any bigger and they wouldn't fit well. The result is an extremely simple battery arrangement with a low part count. Another benefit is that these cells (at least Tesla's version) are designed to be tab-less, meaning they create less heat and are capable of greater charge/discharge rates. I am eagerly waiting for these cells to become available to 3rd party companies so we can see them in wheels soon.

Edited December 19, 2023 by InfiniteWheelie

[Tawpie]

I worry about 2p. But I don't know how the 4680 form factor works under load. Our need for really high currents has meant we wanted many parallel stacks to share the burden and unless the 4680 can deliver high current, it'll suffer the same voltage sag problems that my 3p S18 has.

[InfiniteWheelie]

These cells are 5 times bigger (25 ah vs 5 ah 2170s). Arranged how I described would give 50 ah versus 40 ah for the Monster Pro and Commander. That alone would be an advantage, but the tab-less design of these cells would provide even more power. The number of parallel only matters when comparing the same sized cells, it's the total amp hours of the battery pack (and c rate of the cells) which actually matters. There's no need to worry, it's actually more powerful.

Edited December 22, 2021 by InfiniteWheelie

[InfiniteWheelie]

I see my thread got merged into here which is appropriate, I didn't see this thread.

In response to the people saying these cells are too wide, that's certainly not the case. Maybe some smaller wheels use a single layer of cells, but larger wheels use a double layer. A single layer of 2170s is 21 mm, so a double layer is 42 mm (or slightly less if staggered). These new cells are only 46mm wide, which is barely any bigger.

Perhaps you could argue these cells wouldn't be good for the smallest of wheels, but anything medium and large these are ideal. I mentioned above a 100v, 2 parallel, 4440 wh arrangement for large wheels ("20+ inch"). Another option is a 100v, 1 parallel, 2220 wh arrangement for medium wheels ("18 inch", "16 inch"). Each pack would have only a single column of 6 cells, instead of 2 columns in the previous example. The 4 packs with 6 cells each would be connected in series for 100v.

As you can see these cells are perfect for medium and large wheels, providing 2220 wh or 4440 wh batteries (100v). To make smaller packs would be possible, but would require a lower voltage (small wheels are slow anyway), and the width would remain if placed on the sides.

Edited December 27, 2021 by InfiniteWheelie

[Freeforester]

Apropos fast charging… coming to an EUC (eventually):

 

[atdlzpae]

3 hours ago, Freeforester said:

Apropos fast charging… coming to an EUC (eventually):

This guy doesn't know what he's talking about. I'll go over the video:

2:03 - Wh/kg - "willow hertz per kilogram"
CATL is claiming 255Wh/kg. LIR18650 Datasheet from 2010 shows a density of 206Wh/kg. So... 23% improvement. Incremental, not bad, but not game-changing.
We've been at the limits of li-ion technology for years now. All that's left are incremental improvements.

2:26 - 1000km of range on this battery?
Tesla S has up to 647km of range. Add 23% and you get 795km. Where is the remaining 205km?

The rest of the video is just marketing fluff.

When you see videos/articles that look more like a commercial by non-engineers... Take it with a glass of salt. In mainstream you hear about a "battery breakthrough" every week or so.

On 8/20/2022 at 8:49 AM, Tryptych said:

I have a custom built 52v battery that is 14s3p using Molicel P42a batteries and a bms.

According to the datasheet of Molicel P42a the max charging current is 8.4A and standard is 4.2A. So charging it at 12.6A (4.2A * 3 in parallel) should be safe.

4A is definitely safe.

[InfiniteWheelie]

I made a picture (roughly) to scale using 4680 cells in a full sized wheel (V13 in this example). As you can see these are perfect for EUCs...

The 24 cells shown are all connected in series for 24s 1p (100v). The same is done on the other side of the wheel, making the total battery arrangement 24s 2p (roughly 4400 Wh).

 

 

Edited November 8, 2022 by InfiniteWheelie

[alcatraz]

I'm not sure these cells are made in China at the moment. For them to be cost competitive to a chinese business they usually need to be made locally.

[RagingGrandpa]

It's not graphene, nor a solid-state electrolyte, but the battery inventions continue: 

(a silicon-anode lithium-ion cell)

On 3/26/2023 at 10:56 AM, wstuart said:

 

I dont know if this is too offtopic...... but here is a novel battery chemistry that is double the capacity/kg.  Seems like this may be closer to production than the 275 other novel chemistries out there.  Sorry, I know new battery-tech is a dime a dozen.  This one just seemed legit and close to something we could see in our wheels soon

I really think in 10 years we may see a Patton size wheel that weighs 70 lbs and has the range of todays 3600wh wheels.  We will all be the old timers in the group ride telling the youngins how we had to ride 110lb wheels that only went 70 miles back in the day.

[misterdalto]

On 12/21/2021 at 8:47 PM, Tawpie said:

I worry about 2p. But I don't know how the 4680 form factor works under load. Our need for really high currents has meant we wanted many parallel stacks to share the burden and unless the 4680 can deliver high current, it'll suffer the same voltage sag problems that my 3p S18 has.

my thoughts exactly. higher voltage with minimal parallel has its place in some situations/form factors, but if wanting to use 4680s in a wheel, it would, in all honestly need to be able to physically accommodate at least a 4p. with the mTen4 being available as 20S2P OR 20S1P being a prime example of this on a smaller scale. what you would want to do with something the size of a v13 with 24S2P would not be the same as your intent with a mTen4 with 20S2P or 20S1P. it will be great for higher power, shorter duration peaks in power, while also reducing weight. e.g. stunt, racing,
but would ultimately not be an ideal commuter even if only a low mile range is needed.

yeah, this thought is not even considering what 4680 cells are(or aren't) capable of, have not dove into it honestly and is why being up front about where my perspective comes from.  in my head,  more parallel = more torque, more redundancy. there's not  practical way around fewer parallels in almost any current available technology of this formfactor.

this is also where i understand the philosophical divide between the design of esk8 v euc.
esk8 goes for higher quality electrical components that can draw, output and sustain higher currents from lower voltage systems resulting in a safer PEV at baseline.

without significantly increasing the price of EUC; euc goes for cheaper quality electrical components to undercut costs. so in EUC land, we see watts aka power via voltage driven-lens - higher amounts of power at lower current draw which is also why we find so many low powered cells in wheels, or wheels that cannot sustain the power output their controllers request from the batteries

in euc land we're like 2-5 years behind esk8 in terms of technological developments and example of this is EUC late attention and acceptance to the higher powered cells like molicel p42a and its slightly less capable competitors, other higher discharge cells. 

Edited March 27, 2023 by misterdalto

[InfiniteWheelie]

I made 2 examples of wheels with 4680 battery packs, stripped down but drawn to scale. I think these cells are perfect for medium-to-large electric wheels. They'd allow a huge parts reduction, and a much simpler battery. Hopefully these pictures help illustrate that.

The smaller one is a 20" wheel (14" rim). The entire battery is 36s 1p (151.2v) with roughly 3,300wh. - This battery is very close in all dimensions to the Lynx. A good all around wheel that can go off road, on road, commute etc.

The bigger one is a 23" wheel (17" rim). The entire battery is 36s 2p (151.2v) with roughly 6,600wh. - This would be a street wheel for racing and cruising. Capable of very high speeds, and very stable thanks to the large diameter tire and weight.

Edited December 20, 2023 by InfiniteWheelie