Originally Posted by subcooledheatpump
720 volts is too high for a 460 volt drive anyway.
680 is the max battery voltage.
The dynamic brake chopper activates at 730 volts on most 460 volt drives
Yes, you seem to be correct. I was extrapolating from the specs on my 240V 2HP Fuji/GE drive, which allows 200-400 VDC. My 7.5 HP Toshiba G3 drive specifies the bus voltage range to be 395 to 720 VDC. The 680 VDC you stated is the peak voltage of a 480 VAC sine wave.
50 12V batteries topped off and charging at 14.4V is 720 VDC. At maximum current draw, they might go as low as 10V each, which is 500V. That's for lead-acid, but for Lithium the same principles apply.
Good luck to the OP on his project. I think the 25 HP motor for $675 might be a good choice. The 30 HP drive at $1450 is also probably ideal. You can't go too far wrong on those components, and making your own high power drive is a major project which can be dangerous, frustrating, and costly.
The battery pack is the biggest (and heaviest and most expensive) part of the project. 24 x 12V 105 A-H lead-acid batteries will be at least $2000 and weigh 1500 lb, and will optimistically give a range of 48 miles, but more likely 20-30. Personally, that's what I would do. For a total cost of $4125 you'd have an EV that might need little maintenance for a year. Then you would have enough experience to decide on a replacement battery pack which would probably be at least $6000 but would last 5 years or more. The biggest piece of the puzzle is the actual W-hr/mile (I used 300) which will depend on overall efficiency, weight, aerodynamics, Rolling Resistance
, and driving habits.