Re: Batteries - EV Conversion

On 3/1/2025 2:23 PM, bp@www.zefox.net wrote:

I asked one of my drive suppliers if an industrial high voltage inverter
could be used for an EV controller.  Polyspede makes them rated upto
500HP and input voltage from 380-480.  A regenerative 200HP Polyspede
sells for about 4 grand.  For the bigger ones the price jumps quickly.
One rated at 400HP is almost 10 grand.

 Those horsepower numbers seem exceedingly large. Is it really required?
I'm thinking in terms of 100hp peak, 20hp continuous at most. It
might require a multi-speed transmission, but that's key to efficiency
anyway. Am I overlooking something? A 12 kg LiFePO4 battery can deliver
about a kilowatt for a minute or so. Do you really want 250 of them?

Well, we are talking about a full size pickup truck in my case.  Like I said if we were looking at a gen 1 Miata or a Chevy Luv we could get by with the readily available 90HP 144 volt system.  Might even feel peppy with the fact that electric motors start putting out near full torque from a relatively low RPM.  When you look at working vehicles things change a bit.  Even my S-10 pickup developed around 200HP (190ish if I recall) with its 4.3L V6.  At even 120HP of the Sonoma I had before the S-10 with its 4 banger it was a dog.  It would do freeway speed... down hill with a tail wind.  LOL.
An extended cab Ram 1500 is going to be around 5000lbs.  Maybe heavier with batteries.  Motor is lighter with EV but batteries take that back. Now I don't need highway speed, but there is no real torque benefit to lots of gears.  Not much anyway.  Most EVs drive in 1 or 2 gears.  I think most just have a single speed gear box.  They do not even have a shiftable gear box since you don't need gears for reverse.  Highway speed would not be needed for me, but I don't want some road raging socker mom ramming me with her mini van or SUV or at best riding her horn because it takes me half a minute to get up to speed.
When you get into full size pickup trucks I am thinking 160-200HP is about the minimum for hauling a load and accelerating at a reasonable rate even if you never drive over 55.  I am aware that Chevy put the 4.3L out of the S-10 in a full size truck.  That was really pushing the minimum limit for a full size truck in my opinion.  Still I think that HP range is the minimum for a full size.  Electrics have "some" torque advantages, but not enough to make up a severe lack of power.
For comparisons, all of my gas and diesel 3/4 ton trucks have developed over 300HP, and my current one supposedly bumps over 400HP.  I don't think 200ish is unreasonable for a full size half ton extended cab.  I mentioned that industrial inverters are available in larger sizes for reference, and because larger electric EV motors are readily available, and not oversized for their applications.
My real insight though was, "What if we could use industrial motor inverters instead of auto industry proprietary distribution inverters?"

 bob prohaska
 

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Bob La Londe
CNC Molds N Stuff
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