Toyota Aqua losing power when in high rev.

Well.. I get the impression that the high voltage to 12vdc converter in the car isn't terribly efficient. So if you're drawing your aux power from the 12v bus, you're paying a premium to get it there.

I understand that the most common ways of using a Prius as an emergency generator are to connect the HV battery to a second inverter- one that produces line voltage to plumb into the house. The trick is getting a high voltage input inverter. They exist, there's no huge trick in making them, they're just really rare in the voltage ratings you would typically use with the battery found in a Prius. Anyway, getting the power directly from that battery would be much more efficient overall. The car is still going to burn a lot of gas to go nowhere, but that's occasionally useful.

 

When you press on the brake, the car starts regen charging and lets the engine idle normally. When you take your foot off the brake, the engine resumes charging the battery again. This occurs when the battery is down to 2 bars. It does this to recharge the battery when it's low. This is as designed.
The high rpms that drop down slowly after acceleration is a heat issue. You stated it was super hot, this occurs when the HV battery inside the car is hot. Roll the windows down to let the heat out of the car and then blast the AC until the cabin is cool. But this is also a safety mechanism. It keeps the battery from being overcharged while hot, attempting to eliminate "swell".

Prius batteries are larger, but the one's usually used for the "emergency generators" are the plug in hybrids, which are a different architecture than the Prius and the PC. They are Li-ion batteries which can handle the load better and hold more capacity... to an extent. The size of the Prius Plug-In battery is still not very large and wouldn't work "well" in this situation.

You had a lot of things going on at once (hot car on a low battery), but the car handled it, just gave you what it could.

 

Yeah I was aware of what was happening and why, but wanted to post my experience on this for the OP. I "hope" to be out of my Prius by next year when the warranty expires and I hate to say this, but I could really care less what happens to this car. I nearly wrecked it this afternoon (would have been totally my fault) and in a way I was sorta sad I didn't. But that's a good thing I suppose. My sons a master honda tech, so may as well buy a Honda. (Should have to begin with, but it was an impulse buy)

 

Not sure what issues you've had with the car so far. Even when mine does this, I still get good mileage, especially compared to other cars. But then, I don't do a lot of short trips. Good luck with your Honda, just steer clear of the 2013-2015 models that were made in Mexico... they had quality issues and didn't live up to the "Honda" longevity rumor.

 

We have plenty of people race their Aqua's here. Primarily gymkhana. Watch/log your battery temperature when this happens. Pretty typical. At full throttle, it's ICE+MG2+MG1 feeding MG2+HV Battery feeding MG2. It's a series of back and forth charging and discharging the battery at it's maximum rate, and really heats things up.