DIY EV could get a shot in the arm- Hacking and re-purposing the Prius Inverter for EV use

I won’t go through the weird internet hole I went through to find this fact, but in a thread on the DIY Electric Car forums were someone is swapping a 1970 Opel GT the owner revealed there’s an open source project to turn the 2^nd generation Prius Inverter into a straight EV Inverter.

It’s wild stuff. If I understand everything properly (it’s not finished yet and I still have a LOT to learn about the angry pixies) it may be so overbuilt it could handle a 400HP electric motor and has its own built-in DC to DC rectifier, meaning that it can run 12 volt interior pieces without separate parts- or be hacked to run backwards as a charger for the battery as the creator did, allowing the potential for some kind of DC fast charging. It’s also built to be liquid-cooled from the factory for added resiliency.

With the cost of a DC-DC converter from EVWest being over $220 alone- and their cheapest inverter starting at $1,300 for DC motors only!- back-engineering this would blow the lid off of a serious restriction for homemade electric cars, with each junkyard example going for ~$175 and another $30-50 in parts and new boards. Here’s to hoping this cheap "300Kw" inverter is a reality, but they’ve already had a few motors running on test benches so it might be sooner than we think.

Link to the logic board for the Prius Inverter, 2nd gen. Also gets you to the guy's website where he has several other projects to repurpose OEM parts instead of $1,000+ aftermarket bits. Up to you if you want to load the controller over cable or wifi.

Link to the openinverter wikia. Has basic instructions, clearly was updated from the Opel GT thread within the week.

Link to the active Controller/Inverter design and discussion.

Now that is really cool.

Thank you for sharing!

Stefan said:

Now that is really cool.

Thank you for sharing!

X2!!

There is one out there already for the leaf inverter, but lack of documentation on Nissan's electrical components means the limits are "unknown". 

I'm going to have to sit down and digest this over the weekend. Thanks for nothing, because that invariably results in stupid ideas.

In reply to Keith Tanner :

Agreed. This is why I try to stay off Endless Sphere too.....

I do love Opel GTs (and have always wanted one.)  

I do have a lot of faith in Gen2 Priuses and currently own 3 of them (previously a 4th)

I enjoy learning about the Prius but so little breaks that I don't have much intimate knowledge of how the "really" work.  

Otherwise, im very interested but admittedly confused with feelings of being in over my head.  

I  would love to have it figured out and a subframe made to put the Prius guts and batteries under other bodies , 

Like the coming "VW skate" but at a GRM budget

The inverter handling a 400hp motor thing makes me go hmmmmm.  I'm guessing they are using the max ratings of the IGBTs  which is all fine and dandy for calculations but doesn't really represent what is capable more than about 1 time. Then you get into the problem of what batteries you are going to use to get to 400hp (inverter just delivers whatever power the batteries can deliver).  Tesla batteries will do that but they are $$$$$$$$$. Bolt batteries probably will too but also $$$$$$$. Volt batteries are less $ and will probably break 300hp but you are getting to a low range option at this point. Leaf batteries wont do it and prius batteries definitely wont. Then you get to the diy brain. Usually the DIY brains just take over the inverter and let you decide what you want it to do including pushing it beyond what the manufacturer thought was reasonable and maybe blowing it up. Usually the only way to get the other features like the DC/DC converter is to use a plug in that just lets you use the inverter in stock configuration (stock power) outside of the original vehicle. This is a nice thing about the Tesla setup-it is big HP from the factory so you just have to convince it it is still in a Tesla, not replace it's brain.

TLDR: optimistic power ratings for that inverter, batteries wont do that power without weight and $, and the diy brains usually just makes the inverter work not the DC/DC converter/BMS/etc.

Edit: Damien is a smart dude who has been doing this type of stuff for a while, I have no doubt his stuff will control the inverter just fine.

This is a cool hole!  Nothing meaningful to add but I do want to follow this.  The U-pull yards are charging only around $80 for these inverters...

In reply to MrJoshua :

It's a little more complicated than that, but you're concerns are grounded well.

The real idea is continuous power and maximum power. The inverter "seems"- based on testing and looking at parts- to be able to support up to 300Kw, but such a power level likely isn't continuous, much in the same way an engine can be taken to its redline but likely can't be held at it constantly. Likewise, continuous power is just that.

As for batteries, it depends on your C rating (discharge rating), how good your cooling/heating is, and how many you have. Leaf packs have some poor discharge rates, but that can be 'fixed' by just having a ton of em'. Personally with this inverter, I see it as a method to have a cheap controller for a lowcost-like EV for autocross and the like.

In reply to GIRTHQUAKE :

I haven't examined a prius controller but I am guessing they use 2 sets of 3 600V 600A IGBT's just like the Volt controller. The ability to use "both" controllers for one motor at high power means you are trying parallel IGBT's across two separate controllers. My understanding is you have trouble paralleling IGBT's even when you have a circuit specifically designed for it because they don't current share well and are prone to one going into thermal runaway. Then you get into the trouble of the cooling loop not really being made for the two controllers making power at one time. The prius looks like it might have a larger loop than the Volt but I am not sure how much. So I still contend that it is an overly optimistic rating for any length of time. Don't get me wrong, I love the idea and look forward to buying a populated board some day. I already have a Paul and Sabrina board in a Volt controller that I fully intend to try in parallel on a Leaf motor some day-but I expect it to melt at some point.

I appreciate the heads up on this. Very much in my field of interest. To be studied later. For future stuff.

I need to learn about 'lectricity and computers. 

I am totally not just posting in this thread so I can find it more easily later.

In reply to Knurled. :

That’s allowable. I didn’t just do it. 

californiamilleghia said:

I  would love to have it figured out and a subframe made to put the Prius guts and batteries under other bodies , 

Like the coming "VW skate" but at a GRM budget

You mean like my 3-wheel EV?  This was only about 5 years ago.

nimblemotorsports said:

californiamilleghia said:

I  would love to have it figured out and a subframe made to put the Prius guts and batteries under other bodies , 

Like the coming "VW skate" but at a GRM budget

You mean like my 3-wheel EV?  This was only about 5 years ago.

Did not see that.......but Big Daddy Roth had a cool Trike with a VW motor in it  and a front nose a little like a 40 ford

Knurled. said:

I am totally not just posting in this thread so I can find it more easily later.

Do you know about the Whatchlist function of the board?  To answer that, my guess is that you do not because when I click on your screen name you are not watching any threads other than one about Kia (which was probably and accident.)    As an example, click on my screen mame as you will see all that I am watching.  Then, click on SVreX's screen name and see all that he is watching.  This watchlist sort of serves as a bookmark list of threads you want to be able to access easily in the future.  

For details on how to add something to your Watchlist and how to access your Watchlist, see my words in this old thread.  

https://grassrootsmotorsports.com/forum/grm/cant-access-any-of-my-build-threads/152264/page1/

In reply to SVreX :

I wish you guys wouldn't lie about stuff like that.  I'd totally never do that.

so, does this mean you could hack the prius inverter to extract more out of an MG/2 insitu in a Gen2 Prius?  because, that'd be interesting as well.  especially if it means you can try and drive more power out of the ICE too.

Another "junkyard find" I've noticed recently are that 8th Gen Civic IMA's are around $100 on car-part.com.  Not that they are a "slamdunk", since they are relatively low power, and are meant to be sandwiched between an engine and a transmission... and pulling them in a yard would be really "hit or miss" with damaging the magnets or the stator.  still, though, I wonder if an IMA might be easier to convert to 'alternate use'... especially with a $100 toyota inverter?

I'll have to go check out the endless-sphere thread later.  maybe after I finish picking through the "four rotor ima maybe build" thread on civicforums (?), or was it crz?

In reply to sleepyhead the buffalo :

That IMA thing looks really interesting- I'd say it's about the size of a dinner plate, maybe the thickness of a deck of cards? It's the first time I've ever heard of it, what build threads with it have you found?

Adapting it with a cheap junkyard toyota inverter would open up some neat ideas- off the back of my hand, EBikes could probably use it and the cheap price from a yard would offset the fabrication costs, and it would be a heck of a lot easier to mount than some other motors people have used; probably put up with heat better too. Another idea would be a way to drive independent wheels on something like a locost or other lightweight speedster, but that's assuming these IMAs have the torque down low to move it. Is there any more info on these?

John Welsh said:

Knurled. said:

I am totally not just posting in this thread so I can find it more easily later.

Do you know about the Whatchlist function of the board?  To answer that, my guess is that you do not because when I click on your screen name you are not watching any threads other than one about Kia (which was probably and accident.) 

I don't like getting e-mail notifications so I never subscribe to any threads.

The Kia thread is a bug, EVERYONE is subscribed to it and there is no way to unsubscribe.

In your profile you can easily turn off the notification when someone posts additional to the thread. 

To delete yourself from watching the Kia thread... 

In the pull down tab of Jump to..., find the choice of Your Watch list. 

Once your watch list is opened for that Kia thread there is the capability to Remove. Click that and you are no longer watching the Kia thread. 

In reply to sleepyhead the buffalo :

Also, in looking up that IMA I found this blog where some UK guy tried to run his Insight completely off of it. Pretty small unit to be able to move a car, though it uses the transmission to multiply torque. Still provides a lot of bolt sizes and gives a clear picture of how big it is- I wonder what kind of power and torque you could get out of it? Could be an attractive, cheap little AC motor.

EDIT: Looks like the 3rd Generation IMA on the civic both has more poles AND thicker windings than the one on an Insight- probably generates more torque and has a higher spin, if I understand AC motors properly.

You could possibly 'stack' multiple IMA to get more power ... just sayin'.