You can see that the cooling channels in the Tesla pack are these hollow undulating aluminum shapes. Can imagine they're not very cheap. Also the Tesla packs are filled with some kind of bonding foam, making repairs near impossible.
Is that maybe to reduce the spread of fire? I know Tesla put a lot of work into that. Others too, I hope.
You could probably ship them staggered, but I’m betting they are at a weight limit anyway so making them more dense doesn’t save you anything.
They don’t bother with smaller secondary batteries because the extra manufacturing cost and operational complexity isn’t worth it for a 5%-10% bump in volumetric energy density.
If there any single car that has made the general public comfortable with very expensive batteries in their car: it’s the Prius.
Just Toyota doing Toyota things.
Also I would strongly disagree on the Prius comment. A lot of "HV battery fault" cars out there back in the day, refurbing them was a pretty good business for a while. The NiMH pack in the Prius was the basis for so many slack jawed comments "EVs will never work! You're just going to have to replace the battery every 5 years!"
Your quote about rollout of the Prius is exactly my point. That opinion was widespread when the Prius was introduced. The reliability of the Prius since then has changed public opinion greatly.
NiMH infamously has HORRIBLE self discharge performance in comparison to pretty much any lithium chemistry.
Multiple lithium chemistries outperform NiMH in low temperature performance. Even LFP which is generally not recommended for unregulated conditions below about -10 degree will function at reduced capacity at -40c. Nearly all chemistries, except maybe LMO, have superior high temperature performance.
I also don't understand what you mean by more forgiving chemistry?
Production yields? Modern lithium cell plants can easily do 80%+
Tolerance to production variations? Multiple lithium chemistries are just as tolerant.
Fire/puncture resistance? Multiple lithium chemistries areas as safe or safer
Voltaic efficiency/Energy Efficiency/etc? Lithium chemistries are SIGNIFICANTLY better
Memory effect or reduced voltage? NIMH yes while lithium none
Cycle life? Once again nearly every lithium chemistry is superior. Some even still have acceptable performance after an order of magnitude more cycles than a NiMH cell.
At this point there is literally no reason someone would chose NiMH for a ground up design in a consumer vehicle other than cost ....seriously like none.
Also yes Prius reliability is pretty good, but the reliability and performance of the NiMH battery packs were not even in the range for what would be acceptable in a commercially successful EV.
At the time when commercial lithium batteries were $1000-$5000/kwh hour sure they were a fantastic compromise, but it's not even close now.
If Tesla had started with NiMH they would have been dead meat right out of the gate. Gone out of business in a couple years at most.
There are, for sure, a tons of great lithium chemistries in existence. But, outside of some very specific markets, they are not used in cars yet.
But for LFP or iron based batteries which don't have such issues, the blade design should be cheaper, more maintainable, more space and weight efficient etc. There's no glue so you can actually just switch individual blades. Cooling channels can be straight.