This is my first post. I've been reading other threads for a couple weeks and thought I'd contribute something. I just finished replacing my head gasket. Then the car wouldn't start because the hybrid battery got drained too far over the last 4 months sitting their not being used. I scratched my head a bit trying to figure out how to recharge it. Then I realized I could use my gasoline generator, a large bridge rectifier, and some large capacitors to produce the higher DC voltage that I needed to recharge it. I already had used this setup before earlier on to charge my LiFePO4 lithium battery bank for my off grid solar system. Only difference this time was that I needed to adjust the generator's AC output voltage on its voltage regulator to produce just the right DC voltage I needed. It worked great! I set the generator to output 182v AC which produced 272v DC after going through the rectifier and capacitors. This is what was measured without any load on it before I connected it to the battery pack. My battery pack was at 218v DC when I first started charging it. I measured 240Watts of charging power after it started charging. I only charged it for maybe 5 minutes at the most which brought the battery up to 225v while charging. This was enough to get the car's engine started and allow it to finish charging the hybrid battery. The car charged the battery up to 242 volts DC after it started up. It's about 34 degrees here in Idaho so I didn't bother powering on the battery pack's cooling fan for only a couple minutes of charging. But this should be done normally if you charge for longer periods of time in warmer weather. The two capacitors I used were rated at 500volts and 8200uF. Rectifier was way bigger than necessary as I only pulled less than 2 amps through it. Generator is rated at 10kw. Anyways, thought I'd share this. I posted a Short video on YouTube but can't share it here yet. My channel name is SpoonerTuner and video title is "Charged Dead Prius HV Battery With My Generator" Hope this helps or inspires someone.