Around here, there is a "strip" downtown, where all the nightclubs and bars are... The mainstream "spiffy" high class ones. There is a tradition amongst this place where people just drive down the main strip. It's always been this way. People just cruising down the strip, slowly. Sitting in traffic lights, bumper to bumper, people just sorta cruise the strip. This being said... I like to cruise this strip in stealth mode. However after one or two cruises, the HV battery is pretty well down, and I wonder, is there some way to command the Prius to run the engine to charge the HV battery up to the top, possibly green? While some may feel its kinda silly, it is fun to watch all the drunkards walking about, and I like to go down the strip in stealth mode so people see how quiet the car is, trying to spread the knowledge... It'd be nice to have a way to get the car to charge the HV battery without driving around town for 5 miles.
There's no hills around? or freeways where you can charge? If not, just hold the brake and accelerator pedals together. It's not the most efficient way but at least it won't cost you unnecessary miles on the odometer.
<div class='quotetop'>QUOTE(Tideland Prius @ Nov 24 2007, 02:35 AM) [snapback]543519[/snapback]</div> Heh, No hills in South Florida I've noticed that laying down the accelerator while in park will ramp up the engine, but I haven't noticed any battery charge doing that.
<div class='quotetop'>QUOTE(partipilo @ Nov 24 2007, 03:43 AM) [snapback]543531[/snapback]</div> You need to be in Drive and hold the brake down and then floor the accelerator. We call it "force charging" and, as Tideland said it's terrible for your FE, but you can get a nice pretty green battery for your cruisin'.
<div class='quotetop'>QUOTE(Tideland Prius @ Nov 23 2007, 11:35 PM) [snapback]543519[/snapback]</div> <div class='quotetop'>QUOTE(efusco @ Nov 24 2007, 03:45 AM) [snapback]543537[/snapback]</div> You can also burn out your MG-2 (motor-generator 2, the one connected to the wheels) this way. It's probably the only thing you can do to over-ride the car's own built-in protection. At the alternative fuel fair in Lacey, WA, a year ago, Frank Hudon, who somtimes posts here on PC, showed us a motor that was burned out this way: The foot on the accelerator tells the car you want to go, so it sends current to MG-2. But because you've got your foot on the brake, and MG-2 is connected to the wheels via a fixed reduction gear, it cannot turn. Sending current to an electric motor while it is prevented from turning can burn it out.
<div class='quotetop'>QUOTE(daniel @ Nov 24 2007, 08:41 AM) [snapback]543554[/snapback]</div> Interesting, had not heard that before...I'd like to hear from Hobbit or someone else what their take on that would be, but it certainly sounds plausible. Food for thought. It's not something I've done more than maybe twice in the time I've had the car, but I did do that before the MPG Challenge at Hybridfest. I guess my sense was that with the foot on the brake the current to MG2 was shut off..much like if the car is idling at a stop.
We do indeed suggest force-charging before an MPG competition, even if it pushes the numbers a little artificially high -- we did this for the press people at HF, and they turned in solid eighties and thought it was *wonderful*. . There is no appreciable, winding-damaging current sent through MG2 during force-charging. If you're holding the brake down firmly, there's *no* current sent through it. Even the hill-holding torque at standstill with the foot off the brake only pulls an amp or two from the HV battery over and above the various parasitics. . _H*
<div class='quotetop'>QUOTE(hobbit @ Nov 24 2007, 12:37 PM) [snapback]543605[/snapback]</div> Whew! That's what I thought, but couldn't be absolutely certain...thanks for clearing up that point. Now I wonder what Frank was observing?
<div class='quotetop'>QUOTE(daniel @ Nov 24 2007, 09:41 AM) [snapback]543554[/snapback]</div> That doesn't make sense. Where is the current going to come from? From the battery? No, because current is going INTO it. So, the only source of current would be from MG-1. But, MG-1 is about 1/2 the size and power of MG-2, and some (most? all?) of its current is going into the battery. So, given the that MG-2 is about twice the rating of MG-1, and that some (most? all?) of the current from MG-1 is going into the battery, is there even enough juice available to damage MG-2? Plus, the computer knows that your foot is on the brake, and the gas pedal is entirely electronic, so this is being done with the computer's full cooperation and consent. If the computer REALLY thought you wanted to accelerate, wouldn't it be pulling current OUT of the battery and into MG-2 to increase torque? I suspect that the computer is bright enough not to let the loose nut behind the wheel damage the hybrid system by such a simple act - you probably have to be much more clever in order to kill it.
Just be aware that you may be shortening the HV battery life if you run the Prius like a series hybrid (force charging and then runs on HV battery). The HV battery was intended to be used when the ICE is very inefficient. Stealthing through that bumper to bumper strip of road is a good way to use the HV battery power. However, force charging just to run 5 miles on electric only sounds more like an abuse on the HV pack.
I was just going by what Frank told me. Check with him. I believe he's a Prius mechanic. He showed us a burned-out MG-2 and said this was how it happened. Maybe Galaxee's DH can give us some insight into this.
I tried this once with my classic, and it made a really horrible noise, so I stopped. Do you know if this is ok for a classic?
