Lexus GS450H VCU Support Thread

[Jack Bauer]

GS450H kit build video coming soon.

[Jack Bauer]

[xp677]

Good to know that the JLCPCB rolls of electrical tape come in different colours!

[Bassmobile]

Before I go making videos or writing up How-TO's wanted to make sure that there wasn't already a play-by-play for programming firmware to the VCU over USB with Arduino Studio that I wasn't aware of.

[Jack Bauer]

I certainly have'nt made any. Would be much appreciated.

[Jack Bauer]

CNC machined HV terminal posts now available:
https://www.evbmw.com/index.php/evbmw-w ... term-posts

[RE3Rotor]

CNC machined HV terminal posts now available:
https://www.evbmw.com/index.php/evbmw-w ... term-posts

Can I use the original connection if I have the wiring+connector? I see they are connected to the same two terminals inside the inverter.

[Bassmobile]

Before I go making videos or writing up How-TO's wanted to make sure that there wasn't already a play-by-play for programming firmware to the VCU over USB with Arduino Studio that I wasn't aware of.

I certainly have'nt made any. Would be much appreciated.

As soon as I can get it to work on my own unit I will do so.
Currently, I'm struggling to get both wifi & VCU main firmware to compile. Trouble is with external libraries that the code requires to compile. Without a package manifest it's hard to know what other libs need to be made available to the IDE.
Made an issue on GitHub here -> https://github.com/damienmaguire/Lexus- ... r/issues/2

If anyone could jump on and help out with that, would be much appreciated.

I'm keen on Platform IO https://platformio.org/platformio-ide. It's quite a bit more intuitive than the Arduino IDE. Anyone else using it?

[Bassmobile]

Can I use the original connection if I have the wiring+connector? I see they are connected to the same two terminals inside the inverter.

There should be no issue doing so. So long as the connectors are in good condition, and you can feel confident that they will conduct with no resistance. If it was my project, I would clean the connectors and terminals really well, and use MG 846 high carbon conductive grease on the terminals before connecting them.

Get that grease here: https://www.mgchemicals.com/products/gr ... grease-846

[Eflyers]

CNC machined HV terminal posts now available:
https://www.evbmw.com/index.php/evbmw-w ... term-posts

Can I use the original connection if I have the wiring+connector? I see they are connected to the same two terminals inside the inverter.

Can you measure the dimensions of the connector blades of the receptacle for the battery power in (the bottom one in your photo)? That would be the thickness of the blade, the width, and the length. You might be able to use calipers to do the measurements, or to estimate the dimensions. I'm working with another inverter that has a similar receptacle for battery power in. The connector blades seem to be undersized for the max current they are reported as carrying. This would be 100-200 amps in my case. The blades on my inverter receptacle appear to be silver plated near their ends.
Also, could you include a photo(s) of the connector area of the plug that you have that goes into this receptacle?

Thank you

[celeron55]

Can I use the original connection if I have the wiring+connector? I see they are connected to the same two terminals inside the inverter.

Aren't those the outputs for an AC compressor and a heater? Definitely not enough for supplying the current needed for driving the actual motors, unless you're limiting your GS450H system to something like 30A...

If you mean using those for their orginal purpose, then of course why not.

[RE3Rotor]

Aren't those the outputs for an AC compressor and a heater? Definitely not enough for supplying the current needed for driving the actual motors, unless you're limiting your GS450H system to something like 30A...

If you mean using those for their orginal purpose, then of course why not.

One of the connector comes from the traction battery of the GS450h. If you open up the inverter, the connections actually ties to the two posts behind the block-off plate.

[celeron55]

One of the connector comes from the traction battery of the GS450h. If you open up the inverter, the connections actually ties to the two posts behind the block-off plate.

Wait you're right, there's no other connector for the battery. So one is for original battery on the boost lower voltage side, other one is something on the boost higher voltage side?

So as this inverter has a 30kW boost converter, those are going to be rated for about 100 amps by Toyota. So if you take up all the safety margin, it just might be enough to power the entire system...

EDIT: I wouldn't do it though. I think if you're going to use the GS450H stuff, you want to feed it 400 A, at least sometimes. And you don't want your battery connection to sometimes violently burn up and explode.

[Jack Bauer]

The reason I went out and had those brass terminals made is that to use the full power of the inverter you need to feed HV directly into its main cap thus bypassing the boost converter.

[Eflyers]

This is what Mauswerkz, on his now dormant Blog, did with his GS450H inverter: https://cdn.hackaday.io/images/4500861487049316359.jpg

[Jack Bauer]

Such a shame all that info wasn't shared and had to be reinvented years later...

[Jack Bauer]

Ok so I've been rattling around a plan in my head to get this thing more user friendly. The big obstacle is software. No one seems to want to dive in so I'll have to do it. Now in no way do I have the skills to do this so I'm going to pay someone to basically put a user interface wrapper on the code that drives the inverter. This will involve coding on the SAM3 and on the ESP wifi module to give something like a version of the Hubner interface where things like status can be observed, throttle calibrated, options selected etc. This won't happen overnight and will need extensive testing by many people to get it right. So here we go...

[xp677]

Backtracking a bit, you cannot (should not) use the factory battery/compressor connectors on this unit, they connect to the buck/boost converter and not the inverter. They are also intended for approx 100A max in the Lexus system. Whether or not they can handle more is a mystery. Note that the metal blades are encased in plastic, it is not known how thick they are in there.

Removing the DC capacitor access panel and adding extended posts is the way to go for this.

[xp677]

Ok so I've been rattling around a plan in my head to get this thing more user friendly. The big obstacle is software. No one seems to want to dive in so I'll have to do it. Now in no way do I have the skills to do this so I'm going to pay someone to basically put a user interface wrapper on the code that drives the inverter. This will involve coding on the SAM3 and on the ESP wifi module to give something like a version of the Hubner interface where things like status can be observed, throttle calibrated, options selected etc. This won't happen overnight and will need extensive testing by many people to get it right. So here we go...

What needs doing? I did not know that there was more software work to be done on this. I'd be happy to have a look at this, but wasn't aware it was a thing.

I realise that the hardware has evolved since my early versions, and now includes IO for contactors, a WiFi unit, etc.

What needs adding? Support for various pedals? A way to configure the IO?

The setup system for the Gen3 Tesla charger looked suitable for things like that. Can't we reuse this?

[Jack Bauer]

From my perspective its fine and needs nothing:) However as more of these controllers are selling and more of the knowledge of how to use them is getting out there it needs a more user friendly interface. Even calibrating the throttle seems to be a chore what I'm proposing is a wifi based front end that lets these things be done much easier and shows status of various functions etc. People don't get that even speccing out what this will be takes time and energy let alone implementing it then documenting it. I had a post in the open tasks area which got nothing :
viewtopic.php?f=18&t=642

[Kevin Sharpe]

From my perspective its fine and needs nothing:) However as more of these controllers are selling and more of the knowledge of how to use them is getting out there it needs a more user friendly interface.

Could you document the current setup with a step by step video and see whether that's enough? I think your most recent construction videos are an excellent example and probably enough detail for most people to get the VCU working. A video on wiring up the VCU would also be invaluable for those of us trying to offer 'community' support.

I know you are desperate to start another development project but maybe we can put that off for a bit

[RE3Rotor]

Backtracking a bit, you cannot (should not) use the factory battery/compressor connectors on this unit, they connect to the buck/boost converter and not the inverter. They are also intended for approx 100A max in the Lexus system. Whether or not they can handle more is a mystery. Note that the metal blades are encased in plastic, it is not known how thick they are in there.

Removing the DC capacitor access panel and adding extended posts is the way to go for this.

In that case, connecting to the terminals in behind the access panel will also energize the converter? Then I can use the mod to buck the pack voltage to the voltage for the AC compressor?

[xp677]

In that case, connecting to the terminals in behind the access panel will also energize the converter? Then I can use the mod to buck the pack voltage to the voltage for the AC compressor?

Yes, but you'll need to remove the internal bus bars and add a fuse in line with the converter. I've noticed an issue with the current method of controlling the converter which occasionally makes it do this: https://imgur.com/a/27bV9Ge

I'm still working on why this happens, for some reason every few seconds/minutes of use at high voltage (>300VDC) it makes a loud "ping" sound, and after a few hundred of these, it explodes violently. A fuse, rated to within the rating of the IGBTs, would protect against this. But this is a topic for another thread.

For now, just note that you need to fuse the converter. This is done in the Lexus within the battery pack.

[xp677]

From my perspective its fine and needs nothing:) However as more of these controllers are selling and more of the knowledge of how to use them is getting out there it needs a more user friendly interface.

I'm not sure what the intended scope of this project is. As I imagined, it was always meant to be purely a GS450h inverter/transmission controller, which would always form part of an EV conversion, rather than be the sole controller for a complete conversion. With that in mind, the unit works well as-is, it could be configurable to response to various CAN inputs, many common pedal inputs, and, as you say, a "pedal learning" function would be good (I imagine this would require an EEPROM, however).

With this in mind, it would be necessary for the end user to have sufficient knowledge to integrate this VCU into a complete EV project.

[mdrobnak]

From my perspective you could put together customized versions which drop into various vehicles, like E46 BMWs as there is sufficient documentation to build a Plug-and-Play solution from the control side of things. However, even with that variables like BMS, contactor setup, etc are enough variance that this is not easy to be done for the end user without having knowledge and access to certain tools.

As a result I think it opens up a market for an integrator to put this all together and make some cash off that while still allowing it to be a pretty cheap conversion. Except for the damn oil pump...places on eBay are removing them from the transmission...

-Matt