To EV Mod or not to EV Mod, that is the question...

I've had the Costal EV switch since it first became available. In fact I was the first member of Prius Chat to install it.

First of all, it is NEVER a good idea to run your battery down using the EV switch, because the ICE will have to run later to recharge it. The best use of the switch is in situations when the car should not be running the ICE, but for one reason or other it does. Some examples:

When the battery SOC is high, and the power demand is low (slow speed on level ground, for example) but the car is not yet warm enough, or not yet in Stage-4 operation.

When you are going to drive such a short distance that the ICE would not warm up (less than a minute or so).

You will never get up those steep SF hills in EV mode, because acceleration is extremely limited. HOWEVER, if your short trip is all downhill one way, it would be very helpful to use EV on the downhill leg, since the ICE will serve no useful purpose at all, but would start automatically without the EV switch.

It's also surprisingly fun to be able to shut off the ICE in parking lots.

If you find that, due to the car's not being warmed up enough, it sometimes does not shut off the ICE going down a hill, then the EV switch is a big help.

Personally, I love it.

 

<div class='quotetop'>QUOTE(lhparkiv @ Apr 14 2007, 09:42 PM) [snapback]423462[/snapback]</div>

<div class='quotetop'>QUOTE(daniel @ Apr 14 2007, 10:24 PM) [snapback]423473[/snapback]</div>

Sorry. I'm new to this process. I too am interested in the EV switch. My concern is voiding any warrantee on my new Prius. Where does the switch come in on this issue?

 

<div class='quotetop'>QUOTE(jfogal @ Apr 15 2007, 05:59 AM) [snapback]423569[/snapback]</div>

The Prius sold in Japan and in Europe has an "EV" button. It engages software in the computer that shuts off the ICE (internal combustion engine) if and only if conditions permit. The battery SOC must be high enough, certain temperature limits apply, you must be going 34 mph or less, you cannot be accelerating, etc. If the proper conditions do not apply, the computer says "No" with three beeps and nothing happens. If you are in EV mode and the conditions cease to exist, the computer starts the ICE, again with three beeps.

But the North American version of the Prius does not have the button. It has all the software. Only the switch to activate it is left off. There is a socket, in which a pin could be inserted, but there is no pin there. If you insert a pin, and then ground it momentarily, which activates the software already in the car and go into EV mode, if conditions permit. That's all the switch does.

If you damage the car while installing the switch, your warranty will not cover the damage. If your switch itself causes damage, you will not be covered. But it is very unlikely that Toyota could deny warranty service on damage unrelated to your switch, merely because you had installed it.

As always, there is risk any time you mess with your car. There is also risk (of death) every time you drive or ride in any car. I am not aware of any person who has ever been denied warranty service on account of having installed an EV switch. Personally, it was a risk I was willing to take, because I judged it to be miniscule, and I really really wanted it. And I've been very happy with it. But then, I am a gadget-freak, and the fact that the Prius sometimes runs the ICE when I don't want it to, was the single most annoying aspect of the car for me.

 

Ordered the coastal ev mod and due to arrive Monday.
Since we have two cars the prius has to be pulled out in order to get the electric car out.
so figure it will be nice not to have the ice start up when not needed. Plus daily commute is 6mi. round trip or so and there will be some spots along that route that will be benificial to the ev mod.

I am looking forward to it

 

<div class='quotetop'>QUOTE(priussoris @ Apr 15 2007, 08:14 AM) [snapback]423604[/snapback]</div>

Yup, that's a perfect use for it. You still have to be careful not to step on the gas too hard, though, or you'll kick it out of EV mode...

 

So am I to understand that the EV mod simply tells the computer to be more aggressive about using the battery only (or less aggressive about starting the engine)? And that the software defines the absolute limits, and beeps at you and does what it wants when the system reaches those limits?

Sounds like a no-brainer to me, if you're jockeying cars around the driveway and whatnot--or have a 1 mile commute on flat roads (maybe to the nearby grocery store).

 

<div class='quotetop'>QUOTE(efusco @ Apr 15 2007, 12:07 PM) [snapback]423689[/snapback]</div>

I think it's a lot more complex than only SOC: Engine and battery temperature seem to affect the threashholds. At an extreme, I think it was at a battery temperature of 103 or 105 or thereabouts that it won't go into EV mode at all. Even the conditions to go into Stage 4 operation seem more complex than we used to think, taking into account battery temperature and SOC as well as engine temp. This is all just my general impression.

 

<div class='quotetop'>QUOTE(efusco @ Apr 15 2007, 06:07 PM) [snapback]423787[/snapback]</div>

All I have is a gut feeling. Nothing seems straightforward on this car.