I'm seriously thinking about having my Prius modified to just run on electric!

Tracy,

Welcome to the club. If I can help with any information or contacts please let me know. I just got the ok from my wife to do this last month. I've begun to buy items for the conversion already and I plan to make about five wire harnesses for this type of conversion to make things easer. I'm going for a PHEV not full electric. For a Prius to go full electric it might me harder then you think because of the computers that control everything. We can talk about that later.

 

To the OP, I don't think it's worth it. I've heard of plug-in conversion kits complete w/extra batteries for $10K. Doing anything like that would certainly void the warranty on much of your car. Is that worth it?

I came across http://privatenrg.com/PriusBattery.htm long ago but he notes "With all that extra Ah of battery, your EV mode distances can get rather lengthy. The system doesn't provide lubrication to the planetary gear system during 'EV mode' or 'Stealth Mode' and that is partially why Toyota doesn't allow us very much EV time. Oil inside the hybrid drive housing (transaxle) splash lubricates the bearings, gears, and other moving parts while the ICE powered transaxle-oil pump (not the ICE oil pump) supplies lubricating oil to the planetary gear system. I bought this pump to fit to the HSD and I know where I need to tie in but, after 100,000+ miles, I still haven't done it so, I have had to limit my 'EV' events to 7 miles and then force a startup so that those few parts can be lubricated. I need to install this thing & see how much real EV time or distance I can muster within my SOC ran"

I think the most that's reasonable at this point (for the cost) is the EV mode switch. Even w/that, it's questionable what might happen if say the HV battery fails/wears out before the warranty expires and they find you have the EV switch mod.

Edit: I later stumbled across http://www.calcars.org/howtoget.html. This should help you.

 

<div class='quotetop'>QUOTE(Cheap! @ Dec 3 2006, 07:50 PM) [snapback]357122[/snapback]</div>

Oh really? Is it possible for you to send detailed written step-by-step instructions on how you managed that???

I'm still working on getting her to allow an EV switch. Quoting, "It'll void the warranty. Do you know what you're doing? If it worked good they would have put it on in the first place."

 

<div class='quotetop'>QUOTE(cwerdna @ Dec 3 2006, 05:14 PM) [snapback]357129[/snapback]</div>

Not worth it? That depends if you are talking financially or environmentally. I’ll be the first to tell you financially it is not worth it! However, environmentally is another story as I plan to use wind energy to charge it at night.

Thank you though for talking about the lubrication as electricblue has noticed an automatic ICE spin that happens about two miles in. The ICE is not using gas, but it does spin and we were trying to figure out why. I bet that is it. You may have just given us a great solution to a problem we did not know we had. That must be why the gear system did not overheat as you thought it would. The gears were being lube but a pump might be more efficient and keep the gears lubed and cool enough to stop that engine spin.

Thanks!


<div class='quotetop'>QUOTE(sub3marathonman @ Dec 3 2006, 09:08 PM) [snapback]357198[/snapback]</div>

Well, let’s just say we spoil each other.

As far as the EV switch, Vass went on a trip to meet with head engineer of the Prius and we now have official word. The reason we do not have the EV switch in the U.S.A. even though it is every where else in the world, is because if the EV switch is used improperly, the engine could cool off to much and it would increase its emissions for short periods of time.

As far as the warranty issue, if something were to go wrong, Toyota would have to prove that the switch caused the damage, just as if you installed a CB into your car and the MFD went bad. They could say the CB caused it, but that is not enough, they have to prove it. How are they going to prove that the EV switch is working properly all over the world and then suddenly when it is installed properly on your car something went wrong? Besides that thousands of the EV installs have been done with no ill effect.

What convince my wife about the EV switch.(That I installed while she was out,) was when I drove her and showed her how it worked. We got in and I pulled back my headlight flasher, that is where I installed it, and we drove off silently. Then when the battery got to low and we were on the main road, we heard three beeps and the ICE started. Then while the ICE was warming up, I said watch the screen, and I pulled back the flasher again. A message popped down saying “Cannot enter EV mode now.†When she saw the fact that the programming for the EV mode was already in the car she was convinced.

I installed my first EV switch for free as I already had a piece of 22 gauge wire and some solder. Later I moved it to a push button on one of the blanks as I hated flashing people at night just to go into EV mode. Now I will get a real EV button that should have come with the car in the first place.

 

My bet is wait for the Toyota's official PHEV, perhaps in 2010.

Ken@Japan

 

<div class='quotetop'>QUOTE(ken1784 @ Dec 3 2006, 10:58 PM) [snapback]357216[/snapback]</div>

Now that is a safe bet.

 

<div class='quotetop'>QUOTE(sub3marathonman @ Dec 3 2006, 07:08 PM) [snapback]357198[/snapback]</div>

Point out to her that they did put it in in the first place. And then they removed the button (just the button, not the EV system) from the North American units only, but that everywhere else in the world they still have it in.

Point out to her that all you will be doing is installing a switch that does what the button does on the Priuses sold elsewhere.

FWIW, I personally think the headlight-flasher version is a poor choice, since it flashes the lights at the same time. Go with Evan's version, that uses a dedicated button, or the more expensive but easier to install Costal Tech version.

<div class='quotetop'>QUOTE(tracysbeans @ Dec 3 2006, 02:42 PM) [snapback]357117[/snapback]</div>

I would seriously consider the EDrive Systems conversion, if they were actually doing it. I have no idea what's going on with them. However, it's a very limited system because of the speed and power limitations of the Prius in EV mode. The mod, which I think is based on CalCars' work, adds a good chunk of grid power into the mix, but I doubt it will spend much time in pure EV mode in real-life driving.

What I really want is a proper EV. I'd keep my Prius for road trips.

 

<div class='quotetop'>QUOTE(Cheap! @ Dec 3 2006, 08:23 PM) [snapback]357212[/snapback]</div>

I'm glad you admit that it's not worth it financially as I was alluding to.

So you have a windmill and a consistent source of wind? How can you be sure that any/all of the electricity used to charge the Prius will be from wind?

There's also been talk about the EV switch potentially cycling the HV battery too much and shortening its life. The battery is warranted for 10 years/150K miles in California and a few other states. Is it that long in any/all those other countries w/the EV switch? How about 8 years/100K miles? How many of these Priuses w/the EV switch have been around for 8 years, 10 years or 100K or 150K miles? The answer to the first two parts for the current gene is obviously 0.

I also recall a guy here on Priuschat or Priusonline who damaged a connector in the process of installing his EV switch causing all sorts of probs/weirdness. I wish I could find the thread.

Personally, I think the EV switch is as far as I might want to go (and even I won't do it). Doing extensive modifications so that the Prius can run longer on electric alone like adding extra batteries will surely void much of the warranty.

 

<div class='quotetop'>QUOTE(ken1784 @ Dec 3 2006, 11:58 PM) [snapback]357216[/snapback]</div>

By that year I'll probably drive another 8000 Ml ( very conservative figure) in electric mode only.

 

<div class='quotetop'>QUOTE(tracysbeans @ Dec 3 2006, 05:42 PM) [snapback]357117[/snapback]</div>

I too want a PHEV modification. I've been tracking the commercially available PHEV modifications pretty closely. My post #33 in this thread:
http://priuschat.com/index.php?showtopic=26342&st=20
gives what I think is an accurate summary of the three firms planning to offer Prisu PHEV mods in the US. Might be more out there that I haven't found. Of these, Hymotion appears closest to having a commercially available product.

My understanding is that, for Hymotion, at least, the issue of lubrication of the transmission does not arise. For better or worse. It runs just like a Prius with a very full (green) battery. So, as I understand it, the ICE runs at startup, and runs if you want hard acceleration, and runs if you go fast enough. In other words, the ICE will run a bit anyway. Nevertheless, most of the time, around town, it should be in EV mode.

Other than cost, the main thing stopping me from getting the PHEV mod is concern about battery life. Hymotion, for example, offers a 2 year warranty, the others offer no warranty whatsoever on their batteries. Moreover, for a traditional Li-Ion battery, maybe 1000 cycles (3 years, every day) would be a reasonable expectation of battery life. (Clett, on this forum, is knowledgeable about batteries and suggests that newer Li-Ion batteries will have significantly longer life. In particular, the Altairnano batteries slated to go into Phoenix Motorcars' $45,000 EVs to be offered in CA in 2007 are reputed to be a life-of-the-car battery. But they aren't being used for PHEV mods - yet.) So, maybe the Hymotion warranty is an accurate reflection of the batteries they use, which means that maybe 2 years from now you'll be wondering how to recycle a 200 lb dead lithium-ion battery. (Hymotion, by the way, removes the original Prius battery, so its not clear what happens when the Hymotion battery dies.) For my part, I'd also be wondering whether you're coming out ahead in terms of total fossil fuel consumption. Does the fossil fuel saved by 2 years of EV mode exceeds the fossil fuel needed to create the Li-ion battery? I assume you'd come out ahead, because the US average wall-socket-electric-powered mile produces maybe 60% of the C02 of a gas-powered mile, but it's not clear how much ahead you'd be.

PHEV battery life is short not just because of the Li-Ion chemistry, but because the batteries are used hard (full range of charge), as opposed to the Prius NiMH battery, which the Prius protects by using only lightly. My understanding is that this is why we don't have a US EV switch but we do have an 8 year warranty on the battery in the US. The EV switch lets you use the battery harder. So, my second-hand understanding is that this is why Toyotay has a European setup (EV switch plus lower battery warranty) and a US setup (no EV switch, longer battery warranty), and if you put in an EV switch, you void you battery warranty. Having said that, I still haven't heard of anybody killing their battery with an EV switch -- the car still protects the battery well.

On the issue of an EV switch, you need to understand that that's fundamentally different from a PHEV modification, because of how the battery is charged. A PHEV mod gets charged out of the wall socket. With an EV switch, all the energy in the battery comes from running the ICE. My understanding is that, for the Prius, the environmental advantages of PHEV come because you charge from the wall socket. I also believe that, for the typical user, an EV switch is a (very slight) net environmental negative.

So, for me, it's not the warranty issue that's stopping me from getting an EV switch, it's that a) I can't get anywhere of interest (and back) in the 1 mile EV range, and b) my understanding is that, if you have to warm up and use the ICE anyway, using the EV switch to run in EV mode increases fossil-fuel use. Nothing's free. The energy that comes out of the battery gets put there by burning gasoline in the ICE. And, as Dr. Fusco and others have pointed out here, in threads on maximizing MPG, charging and discharging the battery wastes about 20% of the energy that the ICE produces. So, if you can run the ICE at an efficient load, it uses less gas to run the ICE to turn the wheels, than it does to run the ICE to charge the battery, then use the battery to turn the wheels. (You only come ahead with the hybrid setup because of that "efficient load" clause above -- the electric portion allows you not to run the ICE at times when the ICE would be inefficiently, lightly loaded, such as idling along in traffic and such.) This is why the threads on maximizing MPG say you should not accelerate slowly from a stop using EV mode. You'll actually use more gas that way, due to the losses incurred in the eventual charge/discharge cycle of the battery, to replace the electric energy you used for that acceleration. Instead, you should load the ICE fully with a moderaltely brisk acceleration, then go into stealth (EV) mode once the car is up to speed.

Obviously, if you can use the EV switch to avoid turning on the ICE at all, you can come ahead, because you don't have to warm up the engine. And I'd go so far as to say that some savvy EV switch users might, by using their EV switch wisely, be able to outdo the programming that Toyota built into the car to choose the most efficient combination of gas/electric. And there are times when you just don't want to run the ICE. And if you could charge the Prius battery out of a wall-socket, they you could come ahead (C02 wise) with an EV switch. Or if you just want one, that's OK. But I think that the average user would slightly increase gas usage (and C02 output) by using an EV switch.

At this point, I'm considering the Hymotion conversion. They seem to be the farthest down the road, and I understand what they do (replace the Prius battery with a bigger one, and fool the car into thinking the battery is on "green"). Seems pretty harmless. Right now they are focused on fleet conversions, not individuals, but they promise a 2007 product for individual purchase. Apparently the conversion takes about 2 hours. I just want to be sure it's an actual winner, environmentally.

 

You can absolutely do better with proper use of an EV switch. Such
as lengthening the distance traveled during those nasty warmup
stages, and get closer to 40-50 mpg bargraph segments for that time
rather than those sub-25s that most people see. Once you're in stage
4 it's less relevant since you get shutdown much more easily anyways,
but it's still nice in some slow-n-go traffic for a little while or
trying to play the "empty it by the top" hill-climb game to try and
leave more regen headroom on the way back down.
.
_H*

 

Get the EV button installed. If that's not hardcore enough for you, instead of converting an existing Prius to a plug-in the better thing to do environmentally would be to sell it as-is to someone else and buy a purpose-built electric vehicle. Then there would be two very clean vehicles on the road instead of one.

 

I agree with Hobbit: Correct use of the EV switch can help a little bit with efficiency. Improper use will hurt a little bit. The point is not to "get somewhere" in EV mode. The point is to be able to force the car to act as though it was in stage 4 operation when it is not (cold weather, high SOC), draw down the battery before a downhill, and draw down the battery in the evening, so next morning's compulsory warm-up has battery head room to send all that electricity to.

It is not a substitute for a PHEV or a real EV. But it's the best we can do without spending many thousands of dollars on a radical modification of the car.

 

This is precisely the same question I raised to the HyMotion people,
whose rather indeterminate answer was "we haven't had a problem yet".
After having a good look inside a transaxle, though, it seems that
the system *would* be relatively immune to longish EV stints --
there is a certain amount of splash lube going on, even if minor,
the bearings are mostly ball or roller, and electric motors will
place evenly-balanced torque on shafts rather than the one-sided
pounding that crankshaft bearings take. There are still differing
points of view on exactly how high the transaxle fluid sits in the
sump and how likely it is for parts to pick up some sling without
help from the pump. The pump's output appears to only go down the
center of the various nested shafts and feed various bearings along
the way. I still don't know offhand if there's a specific exit hole
into the PSD itself, but I will try to find out. It's actually
fairly hard to tell where the pump output is channeled to even with
all the parts laid open in one's hands. Should have taken an air
compressor to it while I had the chance...
.
_H*

 

<div class='quotetop'>QUOTE(cwerdna @ Dec 3 2006, 06:14 PM) [snapback]357129[/snapback]</div>

Assuming the quote from privatenrg.com is correct. For people that are going to do the PHEV mod or already done the PHEV mod, how do you solve the PSD lubrication issue? Or is that even a concern?

 

Tracy good luck on your quest. its only with strong proactive consumer demand will the plug ins be made and you will help get it off the ground. its easy to play it safe, wait until the technology has been tested, modified and improved and the cost lowered. but if everyone takes a wait and see attitude, then it never gets started.

i thank you for "taking one for the team"

 

<div class='quotetop'>QUOTE(daniel @ Dec 3 2006, 10:44 PM) [snapback]357261[/snapback]</div>

And I personally think it is a great starting point to determine if you like it. Non-invasive, totally hidden and reversible. If you like the EV mode, you can VERY easily add a switch to control it some other way. The high beams only flash if the lights are already on. They won't flash if starting from off. I started this way, and eventually put in the factory EV switch. The only problem is that I sometimes forget, and still reach for the flasher!

<div class='quotetop'>QUOTE(cwerdna @ Dec 4 2006, 12:19 AM) [snapback]357271[/snapback]</div>

Where are you going with this? Our primary car is a full battery EV. And ALL of the power for that car is generated from the sun. How do I know? Because I know how much my PV system generates, and I know exactly how much energy I put into the car. This is pretty far from rocket science, and is something you cannot do with a gasoline vehicle.

There is little you can do that will "surely" void any of the warranty. Crushing your car may be one of them, however.


<div class='quotetop'>QUOTE(chogan @ Dec 4 2006, 05:54 AM) [snapback]357314[/snapback]</div>

Absolutely! I use it to shuffle my cars around the garage/driveway. Otherwise, the ICE would start cold every time, and there's no question that is a worse situation for pollution and FE. When I'm actually going to be driving the car, I let it fire the ICE and warm up normally.

<div class='quotetop'>QUOTE(DaveinOlyWA @ Dec 8 2006, 10:16 AM) [snapback]359363[/snapback]</div>

As do I!