Stark Battery Tech Thread

[Karinshi]

I'm more thinking smaller updates. Apart from the plug all the outer dimensions of 1.0 and 1.2 are the same. Doesn't seem like a huge amount of trouble to keep that the same in upgraded bikes.

This method of new model every year depreciates value fast, making people less likely to just buy the thing when the model is a year old. Because it will be strongly outdated and no longer upgradeable after a few months.
Also imagine having 8 iterations in 10 years for wich you all mandotory need to sell spares in the EU for the first 10 years. Doesn't sound economical.

Beta for example did improve their engines a lott, but a 2013 engine fits in a 2026.
Honda updates their bikes once a century, not every year.

I get Beagle point and its true... But I don't think manufacturing a new battery with practically the same format would be a problem... they could sell it separately and whoever wants it can buy it for their Varg, both for the current one and for the future improved model... Seeing Stark's creative and daring style, it's quite possible they might consider that a good idea

 

[Bodo]

I get Beagle point and its true... But I don't think manufacturing a new battery with practically the same format would be a problem... they could sell it separately and whoever wants it can buy it for their Varg, both for the current one and for the future improved model... Seeing Stark's creative and daring style, it's quite possible they might consider that a good idea

A battery with the new 26120 cells cannot have the same format of the 100s4p 21700 battery. The existing packaging space will not accept 2x120mm instead of 2x70mm wide, and given it must be a multiple of 100 cells, it would then probably only be 1p which likely results in a lot less than 7.2kWh.

The 120mm cells will likely only be used on the street and adventure bikes (and possibly later other Eicher group bikes), which have a frame wide enough to accept 2x120mm wide instead of the Varg's 2x70mm wide.

 

[Beagle]

A battery with the new 26120 cells cannot have the same format of the 100s4p 21700 battery. The existing packaging space will not accept 2x120mm instead of 2x70mm wide, and given it must be a multiple of 100 cells, it would then probably only be 1p which likely results in a lot less than 7.2kWh.

The 120mm cells will likely only be used on the street and adventure bikes (and possibly later other Eicher group bikes), which have a frame wide enough to accept 2x120mm wide instead of the Varg's 2x70mm wide.

I think the point is that 26120 cells more or less fit with current case dimensions with one row instead of two, which is pretty much the point.

Then yes probably 2 rows for adventure bikes, which would still be way better than... '4 rows with 21700! With 4 rows you'd get 2 rows not connected on any side to the case, they'd never get air cooled.

Indeed change from Varg 1.0 to 1.2 is modest, hence why it's 1.2 instead of 2.0.
But I believe whenever they'll upgrade the battery they'll keep their upgraded batteries as close as possible for the entire motorcycle range, that is using same individual cells for all models (like MX1.2, EX and SM), likely in different packs for different applications like 9 kWh Varg and 14-18 kWh adventure bike and so on. It simplifies logistics so much.

It would be super cool from Stark to offer the possibility to upgrade old bikes with new battery (like when they'll switch from 21700 to 26120) but it might not be worth it for them.
My hope is more that if the market grows sufficiently, aftermarket will develop and independent actors will step in to offer their own battery upgrades, refurbishing, conversions and so on. The kind of stuff you can currently do for some electric cars, and of course the huge Surron upgrades aftermarket.

 

[Erwin P]

But the 1.0 and 1.2 battery's are not interchangable due to the connectors. How stupid is that. Double logistics and "unsatisfied" customers who now cannot spend money on upgrades and are skeptical about buying a 1 year old model.
I just see missed opportunitys here.

Sure if they change an entire frame for the new battery it's something else. But these modest upgrades should be interchangable.

 

[Beagle]

But the 1.0 and 1.2 battery's are not interchangable due to the connectors. How stupid is that. Double logistics and "unsatisfied" customers who now cannot spend money on upgrades and are skeptical about buying a 1 year old model.
I just see missed opportunitys here.

Sure if they change an entire frame for the new battery it's something else. But these modest upgrades should be interchangable.

Oh I know it's raging.
My guess (and it's just that) is that they had sound reasons to change the connector and that given the choice to solve problems by updating the connector design or sticking to the old design to satisfy first customers (and possibly running into more maintenance issues later on), they chose the first path.
But maybe they could have provided some "conversion" adapter?

It goes further than this, like apparently it's difficult to implement the Varg1.2 software on the 1.0 bike. Which is equally raging and damaging to the brand. It could be related purely to the phone but it could easily be more complex than that. Sometimes new solutions might not be compatible with previous versions... we all know that with software not supported on older systems, it's annoying... but that's just the way it is, backwards compatibility is not always possible, especially when systems evolve fast.

No one will go to a car dealership asking them to swap the battery pack for the more recent version, the tech will keep improving but you're pretty much stuck with what you bought... until you change your car.
I know it COULD be simpler with motorcycles, it probably SHOULD, I doubt it WILL.

 

[Bodo]

I think the point is that 26120 cells more or less fit with current case dimensions with one row instead of two, which is pretty much the point.

Then yes probably 2 rows for adventure bikes, which would still be way better than... '4 rows with 21700! With 4 rows you'd get 2 rows not connected on any side to the case, they'd never get air cooled.

Indeed change from Varg 1.0 to 1.2 is modest, hence why it's 1.2 instead of 2.0.
But I believe whenever they'll upgrade the battery they'll keep their upgraded batteries as close as possible for the entire motorcycle range, that is using same individual cells for all models (like MX1.2, EX and SM), likely in different packs for different applications like 9 kWh Varg and 14-18 kWh adventure bike and so on. It simplifies logistics so much.

It would be super cool from Stark to offer the possibility to upgrade old bikes with new battery (like when they'll switch from 21700 to 26120) but it might not be worth it for them.
My hope is more that if the market grows sufficiently, aftermarket will develop and independent actors will step in to offer their own battery upgrades, refurbishing, conversions and so on. The kind of stuff you can currently do for some electric cars, and of course the huge Surron upgrades aftermarket.

I agree, I'd like to upgrade my battery in five years and have 50% more capa at minimal weight gain. Yet, I'm not sure that works. Let me explain:

• the current battery housing is packaged into the Varg frame
• it can't get wider than that, but it may be smaller
• inside are 400 cells (100s4p), and they are distributed into two halves of the case:

pic borrowed from here

• 200 on the left, 200 on the right, each 70mm wide and ø21 with two PCBs and isolation between them (=140mm + x)

Using the same packaging space for cells 120mm long ø26 would not allow

• filling it with more cells 120mm wide + one PCB + one isolation (= 120mm +x/2) in y-direction
• the packaging for 200 cells ø21 won't allow for 200 cells ø26 in x-z-direction

Alas, there's not enough space for two cells l=120 side-by-side perpendicular to the driving axis, thus halved the qty of cells, nor place for 200 cells ø26 in the Z-plane, thus reduced the qty of cells even more. To reach the Varg voltage, you'd need a multiplier of 100 Li-Ion cells in series - though 200 cells won't fit in x-z-direction - you're limited to 100 cells.

At the same time, the 26120 cells of course have more capa than one 21700 cells - but not enough to replace four of them. Looking at the quoted energy density from earlier in this thread, the arrangement of just 100x 26120 cells would have around 5kWh.
There's probably enough engineering freedom to add some more 26120 cells, but it won't break the 200 qty in the Varg architecture - a new Varg architecture with frame packaging and battery position adjusted might break the 200 cell threshold, or even the 300 cell threshold.

Edited to wrap up: we very likely won't see a 26120 battery in the Varg 1.2 architecture as a retro-fit.

 

[Beagle]

Right, new form factor allows complete redesign of the pack, which is the point, to improve cooling and so on.

I am not sure they've mentioned any electrical characteristics like cell voltage? A 26120 pack may not be compatible with the current hardware.

Anyway, from simple geometry, about 150 26120 cells represent a similar volume to the current pack of 400 21700 cells. We don't know the volumetric energy density (they did mention aiming for gravimetric energy density of 330 Wh/kg) but one can expect that volumetric density would also improve so a 150ish-cells pack should carry more energy.
For similar capacity, a 100-120ish pack might be enough but not sure they'd go this way for a future Varg (IMHO it would make more sense to improve capacity rather than to reduce weight or volume at the moment).

As always, thanks for the stimulating conversation, I love it here!

 

[Proxxon]

 

[Karinshi]

Nice conversation; i dont care how they do it, if they change cells, formfactor, shape... IMHO we all need the same weight but with 360wh/kg so we can reach 10kwh, for me it can stay like that for 10 years that i won't care... right now range for me is not bad but i just want that little extra bit more and i will be more than happy