New here. Searched, general questions on PHEV.

I'm not speaking from experience since my Enginer kit hasn't arrived yet. But from what I understand, you won't be able to drive it in EV all the time because the kit uses a DC-DC converter to feed the stock battery. However, the converted can only handle 3,000 watts continuously so that really isn't enough to sustain EV mode for long periods. What I'm hoping my kit will do is allow longer use of EV mode than the stock prius will allow, and better fuel economy when running on gas.

 

Hi Branndon.
I would sugest you install the EV hack first. There are many threads with information on that. I did it on my 2005 so that when I pull the headlight flasher (The way the Germans do on the autobahn to signal wanting to pass) the care goes into EV. This gives 35mph EV till the Prius HV battery goes low.

Then drive your car and see how often the HV battery goes low.

The Enginer 2kwhr system is designed to keep the Prius HV battery at 7bars for about 20 miles in blended mode. So then you can drive your car for about 20 miles without having the battery go low when you are drawing energy out of it to do EV about 1/2 the time.

The Enginer system puts 10a into the Prius HV battery when it is on. EV at 35mph probubly takes 3 times that much. So if you go at 35mph in EV for several miles the Enginer "recharge" of the HV battery will get behind. If you stop at a stop light it will catch up.

If you drive above 35 mph you will run the ICE but the Enginer system will still help your mileage because with a 7bar HV battery the Prius will use more electrons and less gas.

You will always run the ICE to warm up the catalitic converter. Grill blocking will help the warm-up.

The Enginer kit will not give 100mpg. They do not claim that. I figured payback at 10 years. But I am having fun doing this as a hobby.

I hope this helps.

Thanks,
Dan

 

Hi Branndon,

Welcome to the forum and congrats on the Prius purchase.

I just recently started a thread for people to post their average MPG that they get with various conversion kits in the winter--that should give you some indication of what to expect from the various kits (hopefully more people post to give a bigger range).

Enginer does not allow for sustained EV at higher speeds--simply put the kit can only output about 2 kW electric power while the vehicle requires upwards of 21 kW to accelerate in EV mode. If you're willing to drive very slowly you may be able to get some EV driving. The idea is that the system will dump 2 kWhr (well not quite, but close) of power into the OEM battery over a long period of time at a slow rate (eg: you would see a change in mileage over a long trip versus a short trip).

It is important to note that since Enginer does not replace the OEM battery (it merely pushes power into it...so to speak) you end up drawing more power (in EV mode) from the OEM battery than the Enginer kit can provide and you eventually drain your battery and exit EV mode. I'm not saying it isn't possible to drive in EV mode with said conversion, but I think it's a little misleading to advertise 10 miles of EV range...

Since you're new, I assume you haven't come across my many rants about the 52 MPH EV mode hack and its safety / potential-for-damage risks. Send me a PM if you want to know more about it, but I would recommend using more...safe...methods for getting all EV (eg: methods that don't involve clearing all of the dealer error codes and turning the car off and on to get the gasoline engine to start up again...).

Some conversion kits will allow for greater current draw than others. For example, the Hymotion system is a beefier system than the Enginer (it also doesn't replace the battery) as it allows upwards of 7 kW power from the battery (~ 30A at 230v).

The conversion kit that I have in my car completely replaces the OEM battery with a bigger battery thus I have the full 21 kW of power available all the time (except when the batteries are frozen, in which case my battery output is cut in half...still better than the OEM battery in the cold though). For reference, the company that made the kit in my car is Plugin Conversions Corp (PICC).

Having the full 21 kW (the maximum the Prius will continuously draw in EV mode) allows for the system to take advantage of the 70 MPH EV mode system (known as the Hybrid Energy Manager by Ewert Energy Systems)--which lets me to go up to 70 MPH in EV mode.

There's a lot of stuff out there and each kit is unique: the big difference is price--what is practical for you really depends on how much you are willing to pay. I've found that you generally get what you pay for in a conversion kit...

Feel free to post any other questions you might have...this is the place to ask them =).

Andrew

 

The Enginer kit transfers 2.4kw into the Prius HV Battery. The EV hack uses the Japan and Europe EV programing that Toyota put into all Gen2 Prius's. This limits pure EV to 35mph. If I start with the battery at 7 bars and stay at 35 mph, I can stay in EV mode for several miles.

The 21kw for accelleration is only for 10-20seconds after that you are at the 35mph speed and you only need cruise power.

Thanks,
Dan

 

The 3-mile commute is what's killing your mileage. The car never gets a chance to warm up enough to use hybrid mode efficiently. As far as using the Enginer 2kwh kit for EV mode on that commute...forget it. It is not robust enough to do what you want.

If you can afford it, consider the Hymotion or PICC conversions instead. They will give you the EV range you are looking for.

I don't know what winter temps are in Orange, CA, but you might consider getting an EBH and installing a grill block.

 

To me it sounds like the BMS+ would work out good in this situation. With one or two additional packs it should be very possible to do 3 miles on EV. I'm not sure why this method hasn't been more popular, but it is more of a "do-it-yourself" conversion.

Here is a link to somebody who did this and is very happy: http://priuschat.com/forums/prius-p...1-one-year-driving-our-bms-plug-in-prius.html

 

Hi Branndon,

It's designed for moving your car in the parking lot or for parking in your garage or stuff like that. The idea is that you can drive the car for very short distances at low speeds without starting the warmup sequence (which is where a great deal of fuel is burned every time you turn the car on to warmup the catalytic converter).

People also use it for the pulse and glide situations where you accelerate hard (well, there's some discussion as to exactly how hard and I'll let TheForce comment on that since he's an actual hypermiler) with the gasoline engine and then "glide" with the electric motor by putting it into EV mode.

You have to watch the battery bars like a hawk because if you over discharge the battery (say if you go below around 52%) you end up burning more gasoline to recharge the battery than you would otherwise have saved (the gasoline engine is most efficient at moving the car forward and is relatively inefficient at charging the battery...remember the gasoline engine is only around 30% efficient under ideal circumstances).

One other thing: You want to use the gasoline engine for acceleration because, as mentioned above, it is more efficient under load. You do /not/ want to use EV Mode to accelerate. If you gotta use the gasoline engine, you might as well use it when it's most efficient to get the most mileage for your gasoline.

You don't want to be depleting your battery with EV mode.

As for your battery...If your OEM battery is actually dying, you may want to look into the Plugin Conversion Corp (PICC) system from www.pluginconversions.com

As I said before, that system replaces the OEM battery entirely with a 6.5 kWhr NiMh battery thus solving two problems with one big battery. It's more pricey than other conversions on the market but like I said before, you get what you pay for.

Andrew

 

The comments about short trips killing mileage are right on the mark. Your driving situation is just begging for an EV. I assume you realize this or you wouldn't be asking questions about PHEV conversion.

Likewise, the comments about using the EV switch are correct. It is mostly useful for moving short distances at low speeds. There are also some rather specialized situations where the EV switch can be used to burn down the SOC before a long downhill.

Despite the frustration of not getting as good of mileage as you were hoping, take some comfort in knowing that any other car with an ICE would be getting even worse mileage. The only way for you to get better mileage is to walk, take public transportation, ride a bike, or drive an EV.

Tom

 

I agree with Tom on everything except that last point. It is possible to get better mileage on short trips with a PHEV--just not necessarily with all PHEV conversion systems. Ideally if you can do the whole trip in EV you would be fine, though that would require a beefier system.

To my knowledge, the PICC system is the only one that (that is, systems directly from the factory--sorry people running the Hybrid Interfaces system, I wasn't talking about you ) allows you to go straight into EV mode when you turn the car on and drive for the duration of the battery pack until you run out of electric energy and thus turn back into a standard Prius. I know you can hack some conversions like the Hymotion system into doing this (as many have done) but if you go above 34 MPH you won't be able to use EV mode.

NOTE: The PICC system does not allow you to go straight to EV mode if the engine or the battery are very cold--this is to protect both the engine and the battery (demanding power from a cold engine will reduce its lifespan--thus it has to warm the engine up before allowing EV in case you have to floor it in an emergency). For colder environments I would suggest an electric block heater and grille blocking. Purchasing an electric block heater and blocking your grilles are the two most cost effective ways to save gasoline in a Prius in the cold.

(Sorry guys who have heard this before and are tired of it, but this post is for people who are new): The PICC system allows me to go up to 70 MPH in EV mode (granted, EV mode doesn't provide the most power in the world, 21 kW isn't much to write home about but it sure beats burning gasoline). This is different than just pushing the OEM EV mode because the OEM EV mode will actually increase the emissions produced by your vehicle by 8 to 12 times if you exit OEM EV under load (that is, if you exit EV mode because you pressed the pedal too hard or you went too fast). The PICC system goes through a controlled warmup sequence to first prime the engine before using it to prevent that from happening.

I'm not gloating or anything I'm just saying there are alternatives out there that can reduce gasoline consumption and emissions even on short trips, they just aren't necessarily cheap.

Now if you're looking to recoup your investment on a PHEV system--you can pretty much forget about it at this point (unless you're a super hyper-miler which I'm guessing you aren't). No system on the market to date will let you fully recoup your costs in a realistic time frame (even for the cheap Enginer systems you're looking at nearly 100,000 miles unless gasoline hits 8 bucks a gallon--plus don't forget to factor in the cost for electricity which can be as much as 20 cents a kWhr depending on where you live).

No, we don't do conversions to save money at this point, we do it as a statement that cars can (and should) be powered more aggressively by electricity--a sustainable and domestically produced energy source. The idea is that if enough interest is generated in said technology OEMs will have no choice but to follow suit. They can do it for cheap and on mass-scale, presumably. (Plus, it's pretty awesome to drive my car around without making noise...).

Andrew

 

Agreed. I didn't phrase that last statement correctly. I was thinking in terms of absolutes, and should of said "The ideal way to get better mileage is to..."

A PHEV is certainly better than a plain Prius, which is better than a plain car.

Tom

 

Hello Branndon,
Everyone thinks that the PHEV system that they have is the best. Be sure you are getting information from people that actually have and run the system that they are talking about, otherwise the statments may be not quite accurate.

I have the Enginer 4kwhr system in a 2005. I have the EV hooked to my turn signal lever so that when I pull it toward me(what would normally flash the head lights) the EV mode goes on. This works well and is independant of the PHEV system.

I can turn on EV on a cold car but if I get up to around 25mph before the ICE comes on. If the ICE is at 120degF, then EV works up to 35mph. This happens in less than a minute of driving. I do have grill blocking but it is 30-40degF here in Portland Or.

Today I drove for about 5 miles in EV mode. I did this without the ICE coming on at all. It was all city diving so I never did above 35mph. I had several stop signs and stop lights. I started this 5miles at 7 bars on the Prius HV battery. At the end It was at 3 bars and then the ICE came on. The Enginer system was turned on all the time.

I beleive that the Enginer system would help you. You will have the ICE come on to warm up but this will not be as big of an issue as others have indicated.

I sugest that you put the EV Hack into your car first. Then drive it to see how the EV works. You will get EV for about 3/4 mile before the battery goes down to 3 bars. Of cource the ICE will use gas to bring it back up so you will not save any gas but you will be able to experiance how it works. Then understand that what happens for that 3/4 mile can happen for 5 miles with the Enginer PHEV. At that point you can make a choice based on your own experiance.

Hope this helps,
Dan

 

Hi Brandon,
I hope the EV hack gives you some good information. I am now finding that with EV engaged I can get close to 35 mph with the ICE still off, if I am lite on the peddle. It seems to do this even with a dead cold ICE. If you can stay under 35 mph on your 3 mile communte and you are lite on the peddle, you may be able to make it all the way in EV with a 4 kwhr Enginer system. That is with no ICE at all. To do this you need to start with 7 bars on the Prius HV batteries.

You would need to turn on the car, engage the EV so that the ICE does not fire, and turn on the Enginer system and wait for 7 bars. Then start your 3 mile trip. If you do not wait, you will still get good mileage but the ICE will fire some time in the middle of your 3 miles to help bring the Prius HV battery back to a normal SOC.

If I know I have power in the Enginer batteries at the end of a run I leave the car and enginer system on to recharge the Prius HV batteries before turning the car off. Then later I charge the Enginer batteries. Then in the morning I have the Prius HV battery at 7 bars and the Enginer batteries up to full.

Today, I got 89.2 mpg for a 13 mile run. This is one of my better days because I was in town a lot and setting at stop lights enough to keep the Prius HV battery charged up.

Thanks,
Dan

 

Pretty neat stuff. I don't do any short trips, all of mine are at least 5 miles, most are over 20+ since I live away from the city. But once I'm there it would be cool to drive around in EV mode most of the time before heading back home. Could u provide info on the light switch EV mode? Thanks...

 

2-mile commute in EV mode

This is probably true, but it is possible, through careful driving, to go EV, if the streets are fairly level, with low speed limits and sufficient stop lights.

I've had a 4kWh Enginer system for 4 months. I live about 2 miles from work, and can usually drive the entire distance, both directions, entirely on EV.

I use a route with speed limits of 25-35 MPH. The most challenging part of the route is an overpass that crosses the railroad tracks. It's 35 MPH, with 3 lanes in each direction. If the lights are green, I can accelerate up to 33 before hitting the hill, and slow down to 25 when I reach the top. (The impatient drivers behind me usually pass me on the next lane.)

If the SoC is low when I get to work or home, I let it sit for a few minutes to recharge before turning it off or leaving.

 

slightly off-topic:

I recall a rough estimate that the Prius consumes about 200whr/mile ??

if so, the pay-back on installing a photovoltaic system on your roof is half, giving today price for electricity and gasoline. We have installed a 3kwhr system back in 2007; it is actually cheaper now by approx $4K with the current federal 30% rebate. I have took advantage for the $1500 federal energy rebate and installed a large heat pump to heat my house in the winter. I just love that ~300+% efficiency figure. I am now looking into converting my water heater to use heat pump technology, but only after installing direct solar water panel first.

For people in Colorado, it is a no brainer to go PHEV, with that incredible 85% state rebate. When added to the federal 10% rebate, your system costs only 5% ! Albeit I've read that the state Colorada rebate is difficult to get and have yet to hear of anyone obtaining it.

Pb