Took the Prius apart, and also and interesting finding.

After hearing about the battery fan getting clogged in some Prius'es out there, I decided to go ahead and take mine apart and take a look for myself. (I had instructions from a PDF file I found on here.) So I took my Macbook and sat it in the back and went to work. After I carefully took everything out and made sure I didn't stress any panels which was easy because the file I downloaded showed me where all the screws were that I needed to take out. To my suprise, it wasn't that dirty at all. It got me and my Prius closer though, but I went ahead and took the air compressor and blew out some dust that gathered in there and re-installed the fan. By the way, my Prius did something weird this morning, I was on my way back from the park and driving down a LONG road, so I wanted to enjoy the ride, so I set the cruise at 43mph. The MFD displayed that it was using the engine to purely power the wheels, while charging the battery (which was pretty normal.) Well, I looked at my SOC (state of charge) on the screen, 6 blue bars were there so thats fairly normal, thats where it usually sits most of the time while cruising, about 4 minutes later, I look at the screen again, this time 7 green bars, almost full, so I think "hmm, well it must have charged a little more than it needed too." 3 minutes later, I look back at the screen BOOM, all 8 green bars are there, and it was still charging! Then a few seconds after it hit full and was done charging, it used the EV mode aggressively. I didn't know what her deal was, but she's fine now. I think someone at the Green Drive Expo told me that its a battery reset of some sort. Oh well.

 

Here are some pictures I took of this event with the battery this morning on my way home.

 

Yeah, I know that the electric only top speed is 42, then if you go over 42mph, even if your MFD says the engine is doing nothing, it's still spinning. I set it at 43 on purpose because if I ran it on electric only for too long, then the battery would get low then force the ICE into heavy charging, besides, at 43mph, I was getting 53+mpg while charging!

 

It can happen for example, when your getting off a ramp from the freeway. Or at least that's when I usaully experience it. But that time was different, it actually used the engine to charge it full.

 

Wow, I live in the flat lands of Illinois, and I see green bars every now-and-again. Especially when I'm on the highway and set the cruise at 55mph and the engine charges the battery to the comfortable level and then I have to coast all the way down to 35mph because I begin to hit the town, it sometimes goes to 7 green bars.

 

I promise I'm not telling porkies. I had my cruise control set at 43mph (1mph over the limiter for the electric only mode) because I was driving on long, flat ground and I didn't want the battery to go down and induce the engine into heavy charging. So, as the Prius usually acts, the engine was powering the wheels, while also sending power to the battery, AND it had 6 blue bars. Normal. Then about 5 minutes later, I look over again and see the same process, but this time the battery was at 7 green bars, so I thought (Hm, must have charged a little bit more than it wanted too because I know the Prius is comfortable at that 20-80% battery range." Well, wrong, after a few more minutes, bang, the 8th green bar. Then literally 2 seconds after hitting that last bar, it used EV to power the car aggressively.

 

No, max speed for EV mode in all generations in the Prius are 42mph, once you hit 43, you can feel the engine start, but you have to concentrate very hard to get it to 42mph in EV.