carguy123
carguy123 UltimaDork
7/23/21 12:42 p.m.
Robbie (Forum Supporter)
Robbie (Forum Supporter) MegaDork
7/23/21 1:19 p.m.

That's awesome. I want one!

nderwater
nderwater UltimaDork
7/23/21 2:02 p.m.

Great article.  I've been following Palatov for many, many years and have been equal parts amazed and impatient at his progress. His biggest hurdle has been funding, the prerequisite to scaling up and speeding up.  Would love to see what happens with some OEM partner investment.

GIRTHQUAKE
GIRTHQUAKE Dork
7/23/21 10:30 p.m.

Lots of benefits, but a few negatives. One of the good details he didn't mention was that by going single packs you can also use them potentially in bikes, so suddenly you potentially have 2 or 3 more markets to get into before you even leave the street. Less amperage also means you don't need the same pyrofuses that Tesla uses which are massive things built to take the brunt of kilowatts. You've got potential to use something off-shelf, which can save plenty of dosh.

There are problems here; I'm not sure how small a ~400 Volt battery can be. This is assuming a lot, but most of our EVs have been ~400 Volts total because volts equals to "pressure" or "speed" for these motors and is an easy step-up or charge from common 3-phase. Go low volts, you have less rotation and thus less top speed unless you have a gearbox. Making them modular also requires something goofy for a coolant/temperature control system, all current EVs have to use liquid cooling for a reason. Finally, if the cooling system is Leaf-tier you're gonna be seriously limited in charging because you just wont be able to shove power in without heat from resistance- so even swapping batteries might not matter when you're battery swap station has them all charging.

I believe BYD already does pack swaps and they show the limitations of it.

 

nocones
nocones GRM+ Memberand UberDork
7/23/21 11:12 p.m.

If I lived closer I would sweep Palatov's shop until they let me help.  Just anything to be around that level of innovation and quality construction.

Jesse Ransom
Jesse Ransom GRM+ Memberand UltimaDork
7/24/21 12:28 a.m.

Some motorcycle manufacturers have signed, I think, an agreement for a format for interchangeable batteries.

Given the size there, I wonder whether there's any possible overlap here...

If I didn't mix them up, one of the uses is also in one of Honda's adorable straddle-like-a-motorcycle excavators. At least in theory.

Barb_Dwyer
Barb_Dwyer New Reader
7/24/21 8:59 a.m.

In reply to carguy123 :

Excellent article.  Over the years, I have watched Palatov's progress with equal parts amazement and frustration. To scale and speed up, he has faced the biggest hurdle of all: funding.  A little OEM partner investment would be great.

Kreb (Forum Supporter)
Kreb (Forum Supporter) GRM+ Memberand UberDork
7/24/21 11:13 a.m.

Another possible plus of having a standardized battery module would be for racing. You could design a specification around a given battery package and let builders figure out how best to utilize it. 

Oapfu
Oapfu GRM+ Memberand New Reader
2/21/22 5:50 p.m.

In reply to Kreb (Forum Supporter) :

Fast fwd to half a year later, Ultra4/ King of the Hammers  is starting that exact thing with an EV class using spec motor and battery.

wearymicrobe
wearymicrobe PowerDork
2/21/22 6:10 p.m.

How do you balance out multiple packs without charging/balancing them together.

Jesse Ransom
Jesse Ransom GRM+ Memberand UltimaDork
2/23/22 12:41 p.m.

In reply to wearymicrobe :

I don't know the specific logic (like should it be trying to even them out or should it save the "fullest" for high current demand, or...), but I think modern batteries often need management even between their component cells (I don't know at what level of granularity). So I figure a system that can have parts of its battery collection swapped out arbitrarily needs to manage those units individually, but I think that already happens in a way.

Put a little differently, batteries aren't identical, and I think a lot of the modern stuff is sensitive enough that you can't rely on starting "synchronized" to allow you to treat a bunch of cells like one big battery.

That said, I do think there are more individual cells than management circuits in most EV stuff, so we come back to some notion of needing to be "granular enough."

Hrm. Just did a little searching and I think I'm on the right track but haven't found anything clear enough to be a useful link. Samsung talks about a vehicle's pack being made up of modules which are made up of cells, but I'm not sure whether they're managing per-module and calling that good, or whether perhaps each module has cell-level management...

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