Project AKU: GS450h driven by GS450h transmission and GS450h inverter

[jnsaff]

A GS450h with a dead ICE showed up a local classifieds site and obviously I could not resist.

So the plan is to have it ferried to my garage and to start work on it soon.

The first thing I want to achieve is to make the car move around with the GS450h VCU from Damian which I already have without removing the ICE first using its own HV battery if I can.

After that milestone I want to start de-iceing the thing and getting it on the road quick.

For batteries I reckon I have a budget of about 400kg, I could either use the EIG C20's I already have which are high power but a bit heavy, I could get about 50kWh of them. Other option would be to go for a full Tesla pack of 85kWh but the cost would be a lot higher and may not be worth it.

I wan to use the Tesla M3 PCS for charging, DC/DC and CCS. If anyone has one (preferably with the charging port and cables) that they want to sell me for a reasonable price, PM please. There are a lot of Chademo fast chargers around so may need to figure out something for that as well.

The challenge here is to get it all done before the advanced course tackles Lexi, how hard can it be, right?

[PacEmaker]

I admire your enthusiasm and optimism Jaanus!

And looking forward to your first progress report!

Is there a place for our little friend Isabellenhütte in this diabolical plan of yours?

[drprox]

I have been considering this also.

The main challenge I can see is getting the rest of the car to continue to work (aircon / ABS / etc).

There are a lot of ECUs interconnected - even the AC compressor goes via the Hybrid ECU.

The question I am toying with is would it be better to keep the Hybrid ECU and 'fool it' into thinking these items are present:
Engine
inverter
NiMH pack

Or, eliminate the Hybrid ECU and try to get the other stuff to work via 'Hybrid ECU simulation':
Aircon
Skid control ECU
Gateway ECU

I think probably the latter - with some signal sniffing it should be possible.

J

[mdrobnak]

The least amount of signal analysis you have to do, the better.

The upside is there is software (Techstream lite?) that can get you some interesting real-time info that you can use to correlate with items on the CAN bus, for instance. So emulating the ECU may not be difficult, as long as it's not something like the Bosch MED17, which...yeah, no, don't go there.

* Battery pack - if you can sniff the messages from there, and just always report a fully charged pack, should be OK. Or scale it with relation to your actual capacity.

The main issue I see with keeping the HVECU is it wanting to command the engine to turn on past a particular amount of demand.

So, thinking out loud, I'd remove the HVECU.

So, getting a CAN capture, and unplugging the HVECU and seeing what messages go away is a good start to seeing how much work there would be from that point of view.

As far as I know, the VCU from Damien generates torque values to send to the inverter, so putting that type of information back on the CAN side of things for traction control should be fairly straightforward overall.

That all said, prepare to spend a good amount of time on this.

Good luck!

-Matt

[celeron55]

Certainly the first thing I'd do is... nothing. Just charge up the HV battery and see if it moves.

Then, as the GS450H was designed around the same time as the gen2 Prius, I would try if it can be put into an "out of gas mode" like the gen2 Prius, which then moves by electric propulsion pretty much as fast as it can go as limited by the boost converter power and not very far due to the 1kWh HV battery. I have heard and it makes sense to me that you can swap the battery to a larger one if you also swap a custom BMS that talks the prius BMS protocol to the car (not heard of that being done on the GS450H though). Now, what I don't think anyone has tried to do is to feed power after the boost converter and try to make the HVECU request more power from the inverter than what the boost converter would be limited to. So that's something to research on both the Prius and the GS450H.

The HVECU is the most complex computer on the car, so doing that could save you lots of headache. Or possibly just replace that headache with a different kind of headache.

[jnsaff]

Managed to get the car into my garage today, not without some minor incidents. The rocker cover has been taken off on one side of the engine and at some point during our effort to get it into my garage I managed to accidentally get the hybrid system into a state where it wanted to start the ICE. A little scare and small fuel-oil spill but as the ICE is toast anyway I don't care.

HV and 12V batteries are not yet dead so I will keep them charged, connect up can capture and see how I go. Luckily I verified that the power steering pump is on so I will be able to capture those commands, along with AC I hope.

The information on the NiMH battery I've found is that the pack consists of 240 cells with a nominal voltage of 1.2V each adding up to the official 288V and the fully charged voltage seems to be 324V (1.35V per cell). Regular NiMH cells seems to be charged to 1.5V which is 360V. Either way I will try to be conservative as I don't really need to drive with the battery. If anyone has more information on this please let me know.

I will also try to start spoofing the rest of the cars signals soon by disconnecting the Hybrid ECU and reconnecting until I have it all.

Just today I was reminded that Lexus GS has no tachometer but instead is showing power in kW so this will be a very nice touch for the finished EV, I doubt I will (but I sure as hell will try) max out the meter which is at 250kW.

[jnsaff]

So funny thing happened today, as the car had shown that it’s hybrid battery is empty I decided to charge it and see whether I can move it around just by electric power without any modifications.

I pulled the battery out and got it on my bench and measured 300.6V as the pack voltage. So this should be more than half of the capacity of the HV battery. I’m not sure why the car would report it as flat. The module voltages were between 7.30V and 7.68V and some of the connectors had corrosion. I want to clean them up and fully charge and balance the modules to see what the car thinks of it then. According to manual voltages need to be within 0.3V (looks like per 2 modules, so less than that for single module differences).

I did not see any BMS wires going to the cells and am thinking maybe trying to replace the NiMH modules with 79S EIG C20 cells that would weigh about the same but have 3 times the capacity. This would just mean that I’d need to charge the battery less often while working on the car pre de-ice. According to repair manual there are bms voltage sensors every other module. Should also create a charging connector so would not have to lift the sucker out every time.

[jnsaff]

So I got a delivery today. Vol 2 of the ga450h repair manual. This one is about the hybrid system, I also have the wiring diagram book and body repair book coming. If anyone has specific info they want me to look up, let me know.

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[Speedy]

This is the very project I have planned also, so I'll be keenly following along with your thread.

What will you be using to charge the hybrid battery pack in situ?

[jnsaff]

Currently I’m reconditioning the hybrid battery, this involves cleaning the corroded bus bars and charging each module to 8V with a lab power supply. For the full pack I plan to use meanwell led drivers in series. They are CC/CV and the current/voltage are adjustable. The lowest current for the ones I have is about 0.3C which is a bit higher than I like but it should be fine.

My intention is to later sell the hybrid battery as reconditioned and recoup about half of the purchase price of the car. The ICE is probably going to be scrap metal value tho.

[Xenith]

Watching any updates?

[Xenith]

Currently I’m reconditioning the hybrid battery, this involves cleaning the corroded bus bars and charging each module to 8V with a lab power supply. For the full pack I plan to use meanwell led drivers in series. They are CC/CV and the current/voltage are adjustable. The lowest current for the ones I have is about 0.3C which is a bit higher than I like but it should be fine.

My intention is to later sell the hybrid battery as reconditioned and recoup about half of the purchase price of the car. The ICE is probably going to be scrap metal value tho.

Ti start with u seamed yi be powering along with this project are there Any updates

[jnsaff]

So the status of this is that it was a really cold winter and the unheated garage was not very inviting.

I have picked up some work on it now tho. My initial plan was to get as much can capture as I can before starting to deice the car. There are tons of ECU's on the car and I believe at least 3 data bus'es. PT can seems to be really quiet, so I'm a bit worried about whether all parts connected to the PT CAN get all the messages. The most accessible CAN wires to tap were of the Steering ECU and I only get a few messages out of there. Also not sure the car was fully woke.

Besides that I pulled the inverter out and will work to bypass the boost converter for HV and need to also tap the comms lines to so I can talk to it via the OI VCU. I'm not sure that just tapping the lines going to the connector will work when I leave the lines connected to the rest of the car in the harness but I really don't want to cut the harness yet and I have not managed to source a wiring loom with this inverter connector.

If this succeeds I intend to get some spinnage immediately to boost my morale and start to work through rest of the conversion.

The car has a pretty much everything you'd want for a conversion and then some, electric power steering, electric AC as standard. There are also a lot of extra stuff that are cool but probably a pita to get working. Steering ECU, suspension ECU, radar cruise control, etc etc. The sound system is lovely but the entertainment screen is from 2006. So a lot of software work when the time comes, which would be a massive time sink but not exactly rocket science especially if we get more people with the GS450h's converted.

[Lwerewolf]

Are you sure that the engine is going to be scrap money? I don't see many (if any) 2GR-FSEs left in the EU, and they are a somewhat hot item in some destinations (say, Russia - the 5th cylinder wear problems due to dust ingress past the air filter thing).

Anyways, I wouldn't scrap it.

[jnsaff]

Are you sure that the engine is going to be scrap money? I don't see many (if any) 2GR-FSEs left in the EU, and they are a somewhat hot item in some destinations (say, Russia - the 5th cylinder wear problems due to dust ingress past the air filter thing).

I used the term 'scrap' rather loosely here, obviously I'd like to get some more money for it than scrap metal.

[Amoor]

Converting a gs450h is what i planned
And now i have a 100% working gs Runs and drives

Now on how to trick the system i have some (untested) ideas for now
As i drive the car 40+km and the battery is lower then 80% the ecu will send a signal to mg1 to run the engine

Edit (If the car is stand still when the battery is 40% to 30% the ecu will signal the engine to run)

So if we make a pack that is 340vdc at 0%soc and 100%soc is 480v in this case the hybridecu wont throw any codes if we leave it on idle (untested)
So in this case the car will run ac power steering trac abs and airbags no codes

Next idea is we leave the orignal gs inverter as is without playing with it instead we fit another gs450h inverter in the car and wire it to damion's gs450h controller to run both mg1 and mg2

In this way the orignal inverter will run everything originally came with the car and 12vdc power

And the 2nd inverters job is driving both mg1 and mg2

So in this way the first inverter is just runing idle
With accelerator wires disconnected from it

And accelerator wire connected to 2nd inverter

One problem though when the car is cold started the engine will automatically run for around 1 minute and shut down even if we have 100% battery this is something to look at


I planing on testing these soon