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Discussion Starter · #1 · (Edited)
I am planning a late model (+2000) Toyota Celica conversion.

The cars curb weight is 1100 kg (2425 lbs) on the base models.
· I plan to keep the car near the original weight and I believe I can do so using 45 – 50 100 Ah lithium cells. 14 - 16kW battery pack
· I am thinking of a Warp 9 or ADC motor
· I am thinking 144 -156 volts nominal voltage

The only problem with the mentioned 100Ah batteries is I am limited to 3C thundersky and 4C on the CALB batteries. But I don't think I would need a 500 amp draw on such a light car... I don’t plan on racing the car, I just want something that looks sporty and is light.

My area is flat and my current drive to work does not have a speed limit above 90 km/h (55 mph) and my city driving is 60 km/h and under. My current drive to work is ~ 10km (6 miles) one way. As you can see, I don't need a lot of battery, but I do have a friends that live about 35 km round trip, so I would like to be able to have a 65 km (40 mile) range at 70% dod range on this car.

Does this seem reasonable? Could I run 160 volts (nominal) on the DC motors mentioned above with a 400 amp draw limit? Or should I think about going lower voltage with a higher Ah Lithium?
 

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The only problem with the mentioned 100Ah batteries is I am limited to 3C thundersky and 4C on the CALB batteries. But I don't think I would need a 500 amp draw on such a light car...
If you're worried about Amp draw, use more, lower Ah batteries, in order to get your volts up (assuming same total capacity). Then the controller can do all it's fancy trickery to get the volts down to whetever you deem safe levels for your motor.
So you could aim for a nominal 200V from the batteries, but still only see 120V on the motor.

My area is flat and my current drive to work does not have a speed limit above 90 km/h (55 mph) and my city driving is 60 km/h and under. My current drive to work is ~ 10km (6 miles) one way. As you can see, I don't need a lot of battery, but I do have a friends that live about 35 km round trip, so I would like to be able to have a 65 km (40 mile) range at 70% dod range on this car.
Using Franky.EV's spreadsheet, that's very doable.
 

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I was messing around last summer and fall pulling 5C out of my 60 amp hour TS cells. They where up around 2.9 volts per cell and didn't get warm. I cannot pull that for more than seconds at a time because of these annoying things called speed limits. :D

TS list 3C and continuous with the peak impulse current of up to 20C (I don't see for how long, likely 20C is 1 second or less.)

CALB lists 4C continuous with a 8C or 10C for up to 10 seconds (the new 70 amp hour cells list 700 amps, the 100 amp hour cells list 800 amps).
 

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Discussion Starter · #4 ·
If you're worried about Amp draw, use more, lower Ah batteries, in order to get your volts up (assuming same total capacity). Then the controller can do all it's fancy trickery to get the volts down to whetever you deem safe levels for your motor.
So you could aim for a nominal 200V from the batteries, but still only see 120V on the motor.
I am concerned with Amp draw from the point that I want to be within the working bounds of the batteries. I guess I don't know enough about controllers yet. Your statement suggests that I could build a higher voltage pack then have the controller send the final motor voltage output. Do all DC controllers offer this feature?

I want to make sure I have this clear in my head:

200 volts at 300 amps on battery side of the controller would be 120 volts and 500 amps motor side of the controller (assuming perfect world and no losses).
 
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