Featured Munro on KIA EV9

Sometimes Munro focuses on minor details and misses the mountain:

Two out of three ain't bad:

• Wye motor performance
• Delta motor performance
• Missed - step up/down Wye, power transformer
  • Driving one Wye leg doubles the voltage on the other two.
  • Driving two Wye legs halves the voltage on the other.
  • Power is limited by what the motor can handle.
  • Most 800-to-400 VAC converters limit the charging power . . . inefficient and expensive.

Regardless, here is the video:

Motor performance is nice, effectively a two-stage 'tranformation' but the built-in voltage doubling is the real gem. I have long thought about a home, fast DC charger, but the cost of a 40 A , 240 VAC transformer put me off. But if I can get a salvaged KIA 9 or IONIQ 5 motor, problem solved for a fraction of the cost.

Today, my NEMA 14-15 circuit, limited to 40 A at 240 VAC, can provide 9.6 kW. But both of my EVs have vehicle limited converters to 7.2 kW. An affordable, home, fast DC charger would bypass this limitation. Upgrading my circuit to circuit to 100 A, 80 A usable, would give 19.2 kW, 2.7 times faster:

• 1.5 hrs to fully charge depleted BMW i3-REx vs 3.8 hrs on L2 charger
• 2.8 hrs to fully charge depleted Tesla Model 3 vs 7.5 hrs on L2 charger

Of course this begs the question, why? For this retired EV driver with two EVs, not so much. While driving, the other EV is on the charger so I can just drive the other one when I get home. However, it would make a dandy taxi cab or delivery vehicle charger.

Bob Wilson