EV Button

Any thoughts (pros/cons of each) re: the dashboard EV button vs. the EV switch connected to the cruise control stick?

Looks like Coastaletech will offer both, but the cruise control switch is available now.

Also, is my factory warranty toast if I install either one? And what about my purchased extended warranty? Is that void too? Doesnt seem to be a fair trade off... losing the warranties to gain EV mode...

 

thanks for the ev button instructions

Thanks to the people whose work went into creating the pdf file. I did my install today. Took me 3 hours including:

-- 2 trips to radio shack
-- getting the tools together
-- running an extension cord acrossing the apartment parking lot (decided it was easier than putting the car back together to drive it to a closer spot)
-- fumbling with the pin connectors (not sure if I ever got them FULLY inserted; I kind of forced the locking switch down)
-- fumbling with a very weak and clumsy soldering iron
-- fumbling with a drill without the correct drill pieces
-- going through various body contortions to run the wire behind the dash

Cost: $10 for radioshack parts + $20 meter expired ticket (too excited about EV mode to remember to insert quarters I specifically brought along for the purpose) = $30

All in all, it's working now and I hope my solder will hold under vibrations. I love being able to pull out the parking lot confident that I will stay silent.

I believe the ev mode also does not activate when the car has been running and the engine is off (it will activate during engine-off during the first 7 seconds after power-on)

Couldn't have done it without the guide. Thanks again and good luck to others that will try this approach.

Kirby

 

Terrific, isn't it? Lots of fun, but I'm still not sure how practical or useful it really is.

And on my car (EV via the dimmer switch):

when the car comes to a stop and the engine shuts down, if I flick the control it starts in EV mode and the engine won't start till battery, speed, or throttle makes it necessary. Lately, I've been coming off of most lights in EV mode, delighting in the beeps as I pass one trigger point or another.

 

Correction: EV mode does toggle when the engine is off. It just doesn't beep if you're already at the Energy screen.

I gave myself some errands (hmm, what's on-sale at Fry's this week?) and tested for fuel savings. I'm seeing a noticeable improvement for short trips, but it's hard to quantify.

I make sure to not push the EV mode too hard to avoid high current discharge, which hurts both fuel economy and battery life. EV mode will let you go up to 32 mph, but I only let it go that fast if it's a low-load segment. In normal mode the ECU is very sparing about using battery assist, and probably for a good reason -- I was reading about EV1 (the all electric vehicle from GM) owners having to replace their batteries after 20k-30k miles!

 

Driving around with my radioshack EV button today, I did feel it was a little hard to reach and the button a little small. My style is to integrate EV mode switching with my driving -- when I anticipate high drive drain load, I switch off, otherwise I switch on. I did wonder if it would have been better with the cruise control switch -- although the two-second delay could be disconcerting, and it would be awkward to access while turning.

I think when the time comes we'll have to argue our best the modification is not the cause of the problem, and pray that Toyota agrees..

 

I agree that excessive use of EV mode is not a good idea. I use it when I'm creeping through parking lots and I feel the ICE would be inefficient; and when the SOC is very high nearing home my last drive of the day and there would be no place for excess energy to go during the next day's warm-up. Also I would use it (this happened more in winter) if the ICE insists on running even though the SOC is very high and the load is moderate (city driving on flat streets).

I like the installation on the cruise-control stalk, but dislike the fact that that stalk rotates with the steering wheel. Still, the switch only gets used once or twice, in one trip out of 3 or 4. It gives me some control over the car's operation, but most of the time I figure the car knows best.

I figure the chance of needing a warranty repair are pretty small (didn't get the extended warranty for this reason) and I don't expect to keep this car more than 5 or 6 years. I'll trade it in as soon as the next generation Prius comes along.

 

I don't think there's such a thing as "excessive use of the EV mode."

The system is extremely protective of the battery and associated circuitry, and exercises overrides of all sorts. You cannot overcharge the battery, or drain it. If you attempt to draw excess current by accelerating, the system overrides EV and starts the engine.

I initially stuck a momentary spst switch in the blank next to the dimmer, but then moved the control to the light stalk (the "purple wire mod"). It's more convenient. Now, I routinely hit EV whenever I have a mile or less to go with little significant acceleration enroute. And...

When I come to a stoplight near my destination, and the battery's charged, I'll hit EV to keep the engine from coming on - and glide in.

Works for me, and I have no concerns about damage. Warranty, yes. But damage, no.

 

The way I figure, if EV mode did not have disadvantages over normal mode, there would be no need for normal mode. The two possibilities I could think of are fuel economy (if used to maximally supplant the ICE) and battery life.

 

In EV mode the engine does not run. Gotta run the engine to re-charge the battery. That makes normal mode kinda necessary.

The potential disadvantages of using EV mode too much would be reduced fuel economy (assuming that 99% of the time the car can do a better job of judging which is best) and reduced battery life, due to wider swings in SOC. Eisenson makes a good point about the protective circuits. So the minor increase in SOC due to heavy EV use might only result in minor shortening of battery life, and the battery might already last longer than the conventional parts.

But a real advantage of this car is the way that the ICE and the battery together can balance load. In EV the ICE does not run and this balancing does not occur.

 

I'd be real interested in knowing if there is any data to substantiate a reduction in battery life due to the use of the EV switch and the wider swings in BSOC. It may seem obvious, but, hey, until yesterday I thought it was safer to use a handsfree headset in the car....

Since EV mode is automatically disabled whenever the BSOC goes down to about 3 bars, among other conditions, the overall drain on the batteries is no more severe than in full hybrid mode. The stated battery life has to already account for worst case scenario under full-hybrid mode which could include regular discharge to 3 bars, given how the vehicle is used and the conditions under which it is driven. The EV switch is a factory option available overseas and must also have been deemed OK for use in the Prius.

Basically, unless Toyota has identified the EV factory option as a known factor in reducing battery life, then I'll consider it hearsay. In my case, I bought the extended warranty which includes the batteries up to 7 years or 100,000 miles, so I'm not too worried.

 

I'm inclined to agree with you. If there was a known reduction in battery life, they would not have make it standard equipment in Japan and Europe.

I will note, however, that I never saw my battery go down to 2 bars until I put it in EV mode and left it there until the car said, "No more of this!"

 

What I meant was, if EV mode did not contain disadvantages, there would be no need for normal mode "babying" of the battery; the hybrid system would allow the higher battery currents of EV mode *all the time*.

Beyond the SOC swings, EV mode encourages higher current draw and higher operating temperatures. If you play with R/C cars and planes, you will know these are negative factors to battery life.

Anybody know what the hybrid warranty is in Europe and Japan?

 

Re: EV mode logging

I, too, would love to see an authoritative answer to this question.

 

Well guys, I have rented a number of these cars in the last 6 months. I guarantee you the batt will go to two bars every time you nail the throttle on the fwy onramp. Take the speed up to 70 or so with full throttle. Both the ICE and the MG will be putting out 100%. By the time you reach 70MPH, batt will be at 2 bars.

And the looks from the guy in the Porsche trying to keep up with you will be worth the ride.

 

The UK hybrid system warranty is for 8 years or 100,000 miles.

 

My dealer knows about the EV switch and basically told me that as long as the 'check engine' light doesn't come on because of it, they don't care.

 

Re: EV mode logging

Excellent. Personally, I think there is way too much hand-wringing about the possible warranty implications of EV switch installations. However, I would be lying if I said that the thought hadn't crossed my mind...

FWIW I do recall seeing a message on the Yahoo boards that implied that all trouble codes, in addition to radio and MFD presets, would be wiped out if the 12v battery died. I can't attest to the reliablity of the source, though.

 

I have been reading up on the EV button. Those that have it, how much of an MPG improvement have you seen, if any? I live about 5-7 minutes from the highway which I use to go most places unless I go to the shopping center about 2 minutes away. I am wondering if its worth it for me. Most of the drive to work, malls, stores, etc. are on the highway for 90% of the trip.

Thanks

Ryan