Then you would need to assume that 1 row of the 120mm would do the same amount of power as 2 of 70mm.
If so that could mean a narrower battery pack. If not, nobody is gonna want a Varg that can get less far than the old one.
Yes I did this kind of calculations on page 2, I'll update here using Molicel P50B specs.
We don't know which 21700 5.0 Ah cells they use in the 7.2 kWh pack, just that they're not Molicel P50B but since we have to start somewhere, I used P50B specs which are state-of-the-art 5.0 Ah cells with gravimetric energy density of 260 Wh/kg and volumetric energy density of 714 Wh/l, giving a volumetric mass of 2.75 kg/l (or g/cm³).
For 26120 I used gravimetric energy density of 330 Wh/kg (which is their performance target), we don't know volumetric energy density nor volumetric mass so I made an assumption, using volumetric mass of 2.75 kg/l identical to P50B would give volumetric energy density of 908 Wh/l.
So to make a 7.2 kWh pack, as in Varg MX1.2/EX/SM, you could have either
400 21700 cells
total cell weight 27.7 kg
total cell volume 10.1 l
or
124-ish larger 26120 cells
total cell weight 21.8 kg
total cell volume 7.9 l
Of course there are uncertainties in this, in particular precise dimensions for the cells could play on overall volume and volumetric energy density is unknown (though with Molicel P60B given at 888-838 Wh/l, 900ish does not seem too unrealistic). Using Molicel P60B volumetric mass of 3.0 for the calculation would give even smaller pack of 7.3 l.
Bottom line: using 26120 cells, one can expect saving about 25% in weight and volume for any given pack (or more realistically 25% gain in range, that is getting over 9 kWh for the same weight and volume of the current 7.2 kWh pack).
With the added benefit of much better cooling, limiting overheating issues and enabling fast charging.
I would suspect they want the same width since they can keep the same frame, same plastics, same everything. That would outweigh having 2 types of cells i suppose.
I'm not saying they should stick to the old cells. More use the same tech in cells the same size.
Yes but in this case the form factor itself, enabling cooling on both sides for demanding applications like dirtbikes, is a lot of the "new tech". So downsizing it to 21700 would lose many of its advantages while complicating logistics and manufacturing.
