Question about EV mode

In purposeless driving I managed 3.1miles in battery power only(gas engine not on) in a couple loops around my subdivision. Then the gas engine kicked on. The trick is to start out with EV depressed, build up your speed and at about 20mph disengage the EV button, let your foot off the gas at 24mph and slightly depress gas again. You may get to about 30mph with the right touch and road surface. With a series of rolling hills and rolling stops you will go beyond 1 mile. Have fun.

Battery was at full charge when I started this and the engine was warm.

 

The only problem is motor temperature.

After a cold start the ICE always starts to reach the necessary temp.

If you have a warm ICE, you do not need the EV mode. Just be gentle on the accellerator. You can go up to about 45 mph without the ICE kicking in. Make sure there is no traffic behind you. Accelleration is really slow...

When the battery was completely full (after going downhill) I even reached speeds above 60 mph with no gas going to the ICE.

 

i do this regularly. my daily commute the last 5 miles of it is all electric. in normal driving mode just acclerate without crossing the halfway line and the ICE won't come on, on my car, until 47mph. if the engine is warm, and you are going under 47mph, no need for the ICE to run if you mind your right foot.

 

if you had a drive through up hills and down, you would extend the electric range by charging on the down hills. but you would eventually run out of battery and the ICE will turn on to charge for you. you can not regenerate the same amount of energy used to drive the car.

 

If memory serves, pre-Gen III Prius would allow this, but Gen III will not. The owner's manual confirms:


5-2. Steps to take in an emergency

[FONT=Arial,Arial][FONT=Arial,Arial]If the hybrid system still does not start after following the correct starting procedure ([/FONT][/FONT][FONT=Arial,Arial][FONT=Arial,Arial]→[/FONT][/FONT][FONT=Arial,Arial][FONT=Arial,Arial]P. 162), confirm the following points:[/FONT][/FONT]

[FONT=Arial,Arial][FONT=Arial,Arial]The hybrid system will not start even if you are carrying the correct key.[/FONT][/FONT]

[FONT=Arial,Arial][FONT=Arial,Arial]One of the following may be the cause of the problem.[/FONT][/FONT]

[FONT=Arial,Arial][FONT=Arial,Arial]There may not be sufficient fuel in the vehicle’s tank. Refuel the vehicle.[/FONT][/FONT][FONT=Arial,Arial]
[/FONT]

 

There have been times when I use the EV mode in a certain kind of stop and go rush-hour traffic on a freeway. The amount of regenerative braking is a high percentage of time. In this type I can go a number of miles and maintain a good SOC without automatically turning off the EV mode because the ICE needs to start charging the drive battery. You have to keep the speed down to below 25 mph. This is not purposeless driving because you have to stop because of the frequent stopping of the car in front of you. This EV mode is more useful because, if you can keep the SOC high enough through the braking, you prevent the ICE from turning on while going up some types of inclines. Even while going up certain types of slight inclines, you will see the HSI will go to the right side but the ICE will not turn on. Sometimes the HSD turns the EV mode off, but it really depends upon the amount of braking that you are doing.

You can recharge the HV drive battery either through the brake pedal use or while coasting down hill. You learn to feather the brake in order to maximize the regenerative braking (minimizing friction braking with the pads). What you are doing is transferring the kinetic energy built up directly back into the battery without using the normal brake pads, which lose battery energy and turn the kinetic energy (caused by the battery) into heat.

 

if you drive the right speed, and the outside temp is warm enough, and if the terrain is correct, and the soc is high, and no heat or a/c, you can theoretically drive forever without the ice coming on.:wacko:

 

If the ICE isn't running, how do you propose to recharge the battery? If you are coasting downhill you can recharge through regenerative braking, but if you only plan to coast downhill you don't need any power at all.

The OP's question sounds like he is looking for some sort of perpetual motion machine, which of course doesn't exist. Did I miss something, or is this really what this thread is about?

Tom

 

Yep.

Smirv: Consider the source of losses and why the energy is going to have to come from somewhere, in this case w/the ICE running and burning gasoline.

(This may not be a complete list) Aerodynamic drag, friction in the wheel bearings and that of MGs, rolling friction from the tires, and resistance in the battery, wiring, motor windings, inverter and other circuitry causing waste heat. Not to mention that there's a constant draw to power the car even when not in motion. (It's typically at least 1.5 to 2 amps at ~220 volts in my 2nd gen.)

 

Even Death vally in summer is cold for an ICE. Bus as temperature difference is smaller the process of heating engine and catalytic converter takes less time

BTW catalytic converters work best at temperatures between 600 and 1500°F.

Martin