Best Plug-in Conversion System - Please Weigh In

It really depends on how your going to drive it. Are you going to be mopstly driving on the highway or city?

Thes systems do very well on the highway and with an EV button these systems do good in the city.

Hymotion
Plugin Supply
PICC
Any of the Cal-Cars plug in method for DIY.



This one is good for pretty much highway use only or very light city use.

Enginer

 

From what I have read, if you are willing to spend the money, PICC is probably the best. You can get the fastest highway speeds in EV and you don't have to turn the car off to exit EV as with others. At least is will be when the integrate the code so you don't need a laptop to run it. Enginer is the best bang for the $$. Or, you can take my approach, and DIY, but that is not for the faint of heart.

 

Hi Docbooks,

Bang for the buck: It really depends on what you are looking for. If you are looking for an extremely cheap low end system and don't mind if you only see a 10 to 25 MPG improvement for normal driving then some of these cheap $3k systems may work well enough for you. If on the other hand you want a system that will significantly boost your mileage for short trip driving (25 mile and under) without having to modify your existing driving styles (IE: a system that simply just works) then you probably want the Plugin Conversions Corp 25M system. Yes, it is more expensive than the low end systems but it really does work. I drove 14 miles today and averaged 400 MPG (exactly, ironically) during the trip. Granted, this is probably one of the better case scenarios (I drove with a lighter foot than usual), but the drive included 50+ MPH driving. You can normally expect to see between 150 and 200 MPG during normal driving for the first 20 miles or so depending on your vehicle speed.

The PICC (plugin conversion corp) system also does allow for all electric transit up to 70 MPH and does not require you to pull off the road and restart your vehicle to turn the gasoline engine back on (it's all automatic)--which is a huge safety plus as well as a convenience plus. It uses the Hybrid Energy Manager from Ewert Energy Systems which you can see a video demonstration of at Ewert Energy Systems

User friendliness: Again, the PICC system is 95% automatic in nature. All you have to do is plug it in (and unplug it before driving--though it will not let you drive the car until you unplug it). The PICC display system allows you to select the length of your trip so it can optimize when it uses the electricity--something I don't believe any other conversion currently offers. Most of the other low end systems require you to flip switches or push buttons to turn the system on and off--the PICC system is entirely driven by microprocessors and thus all the transitions are automatic. Since the PICC system replaces the OEM battery entirely, there is no need to flip any switches to shut off DC/DC converters or anything when you run out of battery power--it just switches over to the normal hybrid mode.

PICC is also working on a new display system that will interface directly with the Prius MFD (multi-function display touchscreen)
which makes it even easier to switch modes (EV, Plugin-mode, etc).

Good real world results: As I mentioned above, the low end conversion systems require you to drive special (or for example, require you to turn your car on and leave it parked for a few minutes to let the DC/DC converter catch up because it can't transfer enough current to power the car). This means that if you (the average end user) does not want to drive really slow then your real-world results are probably going to be in the 65-80 MPG range--much worse in the cold of course.

As mentioned above, with the PICC conversion I see anywhere from the low 100's to the mid 300's for the first 20 miles depending on how I drive (and of course, how far I drive. As with any conversion, once the battery depletes the mileage quickly drops). If you only drive 25 - 40 miles a day and can charge it at least once a day (over night, for example) you should see well above 100 MPG on average (EG: I've driven 700 miles on this tank so far and I still have 4 bars left...and lets just say I missed a few days of plugging the car in and it got cold here which means the gasoline engine runs more for heat).

Customer service: All I can comment on is the PICC system. Kim Adelman (president of Plugin Conversions Corp) is very helpful and is willing to stand by his conversion if problems arise. They have a 30 day return policy where if you don't like it, you can return it.

Final thoughts: I mentioned above how the PICC system was a higher powered conversion than the lower end systems. This is because they replace the OEM Toyota battery with their own bigger battery. Other conversion systems such as Hymotion and Enginer keep the OEM Toyota battery and instead feed energy from an extra battery pack to it via a DC/DC converter. This works okay if you just want a small boost to your electric usage but it's not too practical for large-scale electric usage. A DC/DC converter like the ones used in these conversions can only transfer about 10 to 25 amps between the extra battery and the OEM battery. On a hot summer night when you have your headlights on and air conditioner on your car might draw around 10 or 11 amps just in park--you can do the math but that basically means you're powering just your headlights and AC from the converter. If you try to drive the vehicle with the battery you end up running out of electricity because the DC/DC converter can't keep up. With the PICC system the the extra battery /is/ the OEM battery that directly drives the car thus you can use the full power of the battery until it runs out of energy without having to pull off the road and let the battery charge up again. This enables that system to fully utilize the electric motor before using gasoline.

Like I said to start with--it all depends on what you're expecting. If you're expecting 100+ MPG under real world conditions you probably want a more powerful conversion. If you just want something to show friends and poke fun at car companies with--you may be able to get by with something less expensive.

You can find more details about the PICC kit at:
Plug-In Home

Hopefully this helps you some.
Andrew

 

Well I can vouch for PICC's customer service. I've had one installed since August. Originally I was having issues with the programing of one of the control boards. Since my conversion was done in Indiana and I live in Houston going back to my installer wasn't really an option. When the modified boards were available Kim Adelman personally came to Houston and together we swapped out the control boards. I'm very pleased that they stand behind their product so well.

 

Why is the PICC kit better than the Hymotion kit (disclaimer - I have the Hymotion kit)? Hymotion is 5 kWh with a "blended" range of about 30 - 40 miles. I have been able to get up to 110 MPG during my 28 mile commute to San Francisco, which involves several steep climbs and freeway speeds up to 75 mph. My average MPG over a year of making this commute with the Hymotion pack is about 85 - 90 MPG. I have had several days or R/T MPG of over 100 (I can plug in at work). The Hymotion software appears to turn off the ICE when the battery can power the car alone, even at freeway speeds. I have been traveling at 65 - 70 MPH and have seen no gas being used either on the SCAN gauge or the Prius MFD. Unlike the PICC kit, however, the Hymotion will not let you select EV only mode. I would estimate that under flat lower speed conditions where the PICC kit gets 25 miles EV, the Hymotion would get 20 miles in EV mode.

The advantages of the Hymotion kit is that it is very simple to use and has Lithium Ion Phosphate batteries that should outlast the NiMH batteries and weigh substantially less. Hymotion also has a large install base and has a few years under their belt. I have had the kit for a year now and have had no problems with it. From reading about the PICC kit, I would say it has some advantages as well - notably a larger capacity, the ability to capture regen braking, and a more sophisticated user interface that allows for things such as EV mode to be selected by the driver. The downside, of course, is that the PICC system is $3500 more. The other downside for PICC has to be the weight of the system. I could not find any information on their site, but this pack has to weigh in the 300 pound range, which means you really need to upgrade the rear suspension with heavier duty shocks and springs - which could easily add another $500 or more to the cost (perhaps PICC includes this in their system price?).

One thing I should point out about PHEV kits is they really do require you to change your driving style to get maximum results. The stock Prius can pretty easily get 50 MPG with pretty normal driving styles - no hypermiling techniques required. If you drive a PHEV Prius aggressively at all, you lose many of the benefits - to the point IMO that you are wasting more energy than just with a stock PRIUS alone. As an example, my wife routinely gets 50 MPG in our Prius (with no Hymotion assist) on the same drive to San Francisco as my commute. If I really work at it, I could get maybe 52-53 MPG under the same circumstances. If I add Hymotion assist, I could double those numbers and maybe get 100 - 110 MPG; whereas my wife with the Hymotion assist would get maybe 75 - 80 MPG as she does not change her driving style (mostly this requires playing the momentum game as opposed to just setting cruise at 65 - 70).

 

If you want the ablility to "plug-in", I would choose the Enginer 2KW kit for $1995 ($3495 for 4KW). This is a good way to understand the plug-in concept and to get familiar with how the system works without paying over $10,000.

I researched both Hymotion and PICC and found them to be too pricey, techy and complicated for a layman like me. I just wanted to be able to enhance my Prius to plug-in without selling one of my kids on ebay:lol:.

Anyway, like the others have said before me. It depends on the performance you want. I have been intrigued by the high speeds at which Hymotion and PICC have been able to stay in EV, however, I have found the Enginer to meet my expectations because of how I have learned to drive it. BTW, you do not have to turn off the car or stop go to into EV mode. For the price, no one can beat it.

Hope this helps your decision process.

JOANNA

 

Oops pressed the wrong button. Sent twice.
Joanna

 

The PICC kit is better because if you try to do too much EV with the Hymotion battery it will start to drain the stock battery. I have found if you draw more than 30-40A continuous you will discharge the stock battery possibly draining too low. With the PICC you can draw 100A continuous and wont have a problem since there is no stock battery to drain.

Since you can draw more amps and not worry about damaging a stock battery the PICC can do its thing to use more electric at higher speeds.

If the PICC was available now with A123 LiOn batteries and has its interface integrated into the MFD I think I would switch to the PICC kit.

I know the NiMh batteries are good enough to get about 80% for the life of the car but I would prefer LiOn since it would be 1. More light weight for the same kWh or 2. You could stuff more kWh in their for longer range. Plus the A123 LiOn have been tested over 9000 charge discharge cycles and still hold over 80% charge.

 

As a broad class distinction, at this point I would say that any
system that's contactor-based, i.e. banging two big batteries
together electrically without regulating the current between
them, is not worth looking at. Especially with mixed chemistries.
.
_H*

 

I found this on the PICC info sheet from Luscious Garage

Additional Weight: 250 lbs (kit includes upgraded rear springs)​

So it's included as part of the cost of the conversion.

I posted a full copy of the info sheet on this post at Prius Chat.

 

zcat3 brings up a very good point. The benefit you will see from a PHEV over a stock hybrid is dependent on 3 things: The number of miles you drive each day, your access to plug-in power, and the way you drive.

If you have a 90 mile commute each day and you can't plug in at work you are not going to see much benefit. However, if like me, you drive 20 miles or less each day you will have the ability to do a lot of pure electric only driving which will raise your overall fuel economy. I drive 3 miles to work and total of 18 to 20 miles each day. My mileage on my PICC conversion averages 115 - 130 MPG. However, I have a friend who does more driving each day with a Hymotion conversion who averages 70-75MPG.

Access to plugs is important. I have a plug at work and home and can plug in just about every time I get out of the car. This increases your MPG as you are doing more driving with a "full tank" of electrons. If you can't plug in at work your mileage will decrease.

Finally, how you drive makes a big difference. If you want to just get into your car and hit the gas you won't see the benefits that you would if you spend time mode-switching and planning your route to avoid freeway speed driving. The amount of energy needed to overcome wind resistance at freeway speeds is much greater than at 30-40 MPH. Part of my high MPG average is the result of traveling on surface roads at 25-40MPH instead of on the freeway at 70. As I said, my commute is 3 miles, so this is not much of a hardship. In fact, I quite like it. I am enjoying the slower driving and the increased connection to the neighborhoods I drive through.

Finally, when comparing conversions I think one of the most important factors is regen. Let's not forget that the stock Prius gets all of its electricity (and hence efficiency) from regen. The PICC allows full regen just like the original Prius battery. This "free fill up" can be quite significant. A few nights ago I traveled 8 miles to my friend's house almost all uphill. When I left his house to head back home my battery was at 65% state of charge. Eight miles later at home at the bottom of the hill I was at 73% state of charge. Essentially, I drove 8 EV miles and recharged my battery 8% at the same time for free.

Good luck in your research. Happy driving!

 

Just to clarify the PICC weight issue:

The new battery adds 220 pounds to the car. The suspension upgrade id part of the conversion and is included in the price. Luscious Garage adds bigger springs to the car to handle the extra weight. I believe this is 40 pounds more than the Hymotion pack.

Battery weight becomes a bigger factor in your MPG if you drive longer distances each day. If you drive 20-30 miles each day you are going to be doing most of your driving with a full battery and the electric drive will increase your MPG a great deal. However, if you drive 60-80 miles each day, you are going to be doing a lot of driving in depleted battery mode. At this point your conversion will act like a similarly to a stock Prius except it has more battery weight in the back which can decrease your mileage.

 

Yes, this is correct though the extra weight is not as bad as you might expect. Since the PICC conversion battery has a lower internal resistance than the stock battery, the overall efficiency of the battery is higher and less of the energy is burned off as heat (it also allows you to capture more energy on regen-braking than the stock battery does). This helps offset some of the additional weight of the bigger battery pack. The end result is effectively the same mileage you would see with a stock battery once you have depleted (EG: if you are going on a very long trip w/o charging).

Andrew

 

I disagree that the systems all work out to be the same (I haven't filled up my car since early August and still have over 3 gallons left running the PICC system) but it does really depend on your needs. Good luck with the conversion =).

Andrew

 

I have only driven the BMS+ conversion system (from Norm at hybridinterfaces.ca ) , so I can't say it's the "best", and of course it all depends on your commute, weather, terrain, and mainly on your budget versus DIY abilities.

The BMS+ system as installed in my 2007 Prius cost me only $2200, and has performed perfectly for well over a year now. But my drives are short, and I can stay in ev most of the time, under 34 mph. I built my own charging system and cables. You have to be very careful with all of this high-voltage equipment and with the safety controls when charging NiMh batteries.

The BMS+ system has many advantages--if it fits your situation, I would certainly consider it. For more information, see my thread at http://priuschat.com/forums/prius-phev-plug-in-modifications/65501-one-year-driving-our-bms-plug-in-prius.html or at One Year of Operation in a Plug-in Prius with Norm’s BMS+ System (slightly more detail).

NW BMS+ Driver

 

I would add a note to this, if you do go BMS+ route make sure you routinely check the voltages on the extra Prius battery packs both at the high end and low end. BMS+ does not (when I last examined one) check the voltages of the two additional battery packs and if they get out of balance (happens over time) it can lead to overcharging or undercharging the batteries (inflicting permanent damage to them or worse). As long as you get the batteries balanced when you put them in and they are roughly the same calendar age you should be OK.

It's probably more of a hobby do-it-yourself approach (okay, it definitely is) but if that's your cup of tea... =)

Andrew