LeonidE

Battery output: 37kw
Motors: 123kw+50kw

Why have battery pack with just 37kw max power while motors can run at 173kw?

tempestv8

Maybe the motors are not just powered by the traction battery's limited output, but also getting juice from the generator that's built into the transaxle, so overall, there is more electric power due to combined traction battery and generator.

ukrkoz

Motor generator is getting electric supply, for motive force, ONLY from traction battery via inverter. ICE does not supply any electricity to MG directly via the other MG that acts as generator. Or not. Depends what ECM tells it to do at the moment.
Traction battery NEVER gets depleted for ICE to "take over". There is minimum threshold at which ICE power is taken away to start charging traction battery.
If traction battery is depleted, vehicle becomes inoperable and won't move, as there will be no way to transmit ICE output to wheels, as it is all done via MG. Hybrid, Toyota hybrid, can not move with depleted traction battery, even if ICE were fully functional.
Hybrid ICE is tamed down on HP. Hybrid V6 under same capacity has lowered HP vs its brethren in conventional RX with same engine. Check specs. I think, they compensated for additional HP + torque from MG.
You can't take MG hypothetical output power and arithmetically add it to ICE power. It does not work that way. Total output is what spec says, not what owner wishes. This been discussed ad nauseam at toyotanation, by yours truly included.

ericsan13

Sooo....don't continuously race uphill WOT after each stoplight? No problem.

Htony

There is good Youtube tutorial how the system works(designed by NEC) by a tech college training Toyota hybrid technicians.