openinverter forum

I finally got a donor Lexus GS450h home in the shed - the idea being to use as much of it as possible to convert a 1951 Hudson Pacemaker into a user-friendly EV. I have Damien's V1 controller board for the GS450h inverter but haven't tested it yet.

This GS450h was advertised as 'theft damaged' with no key. Thankfully I found a key under a pile of trim on the passenger seat. The 12v battery is missing, the NiMh traction battery is disconnected, and various looms are disconnected under the bonnet. What looks like the original (charred) inverter/converter was sitting in the trunk. There's a replacement inverter/converter installed under the bonnet, and a replacement ABS ECU appears to have been fitted. Lots of pages of tech data was inside the cabin as though the workshop had tried valiantly to get the car fixed but failed, hence it was written off by the insurance company. Basically a mystery for me to solve!

Firstly the charred inverter/converter - how it got so charred - something shorted, maybe. Better find some high voltage gloves before I go much further ... The Lexus and the Hudson:

Not sure how internal damage to the inverter can create charring on the outside. I'd open that thing up and have a look inside. If you're lucky, you may have another working inverter.

I've seen a "blown" GS450h inverter before, it was pretty spectacular inside.

Looks like the charring on the outside came from the vent hole under the black cover - here's what the DC bus/cap connectors (?) look like! Seems there's very little magic smoke left inside this thing all I can smell is entrails ...

PacEmaker wrote: ↑Fri Mar 06, 2020 11:04 pmall I can smell is entrails ...

Far be it from me to waste a fresh corpse.

Plenty of miles still left on that one.

Get to her while she's still warm if you can.

I'm over east a bit, doing similar with a couple of Teslas and a Chevy. Love these voltrod projects, there are more turning up every month now.

Good score on the donor car, could it have been an indie mechanic got way out of his depth and then suddenly the car was stolen?

57 Chevy wrote: ↑Sat Mar 07, 2020 7:17 pm ... could it have been an indie mechanic got way out of his depth and then suddenly the car was stolen?

I did wonder about that

Now I see what a GS450h inverter looks like inside. Seems to have experienced a thermal event of some kind ... still got me mystified as to how 'theft damage' resulted in this much smoke escaping.

That looks like a high current, low voltage event rather than something on the HV. All the HV gear I have blown up goes bang and flies to bits without much smoke. Unless there was water in it, then fun stuff like that happens

Did the main cap let go, rather than the power stage?

PacEmaker wrote: ↑Sun Mar 22, 2020 8:00 am ...still got me mystified as to how 'theft damage' resulted in this much smoke escaping...

They might tried to tow that vehicle while it was shut down and MG2/MG1 did its magic

konstantin8818 wrote: ↑Sun Mar 22, 2020 4:23 pm

PacEmaker wrote: ↑Sun Mar 22, 2020 8:00 am ...still got me mystified as to how 'theft damage' resulted in this much smoke escaping...

They might tried to tow that vehicle while it was shut down and MG2/MG1 did its magic

yes Konstantin, that's exactly what I was thinking last night - either the thing was towed or rolled down a hill...

Dilbert - the main cap measures correct capacitance, and later this morning I'll check it for leakage on my old Sprague TO-5!

I'm wondering if the converter side of this box is still functional, or at least has some bits I can salvage...not exactly a priority now but just a thought.

Dilbert wrote: ↑Sun Mar 22, 2020 12:43 pm Did the main cap let go, rather than the power stage?

Nah, the main cap measures perfect using my old 'capacitor analyzer'! The power stage went poof and I think the stator windings in both MG1 and MG2 are partially shorted.

Planning for battery location/s -

I'm thinking to put a spare tyre under the boot (trunk) floor where the fuel tank previously resided. The Hudson boot is over 1.2m long so I have some space to play with for batteries, but plan to put most of the batteries in the engine bay to keep weight distribution roughly how a GS450h would have it. I expect I'll be fitting a fair bit of Lexus running gear into this old hulk...

I want to keep some practical space in the boot for normal use, so the logical rear battery space is the shelf behind the back seat. Boot 'shelf' above the diff measures 1070W x 355H x 410L, but I can extend a bit into the main boot space as required I guess.

I put my name down for 24 of the BMW hybrid batteries if the group buy goes ahead. Perhaps I could aim to fit 36 but I need to find realistic sizing data. The packs of 6 are a shape to suit the BMW hybrid platform and not so space efficient for conversions so I'll be stripping them down and re-configuring them into the available spaces in the Hudson. I read somewhere that 'BMW' cells are 369mm x 178mm x 102mm each but not sure if these are the same ones in the BMW hybrids. Searching the wiki and threads here on open inverter I haven't found cell dimensions yet.

So I'm curious what are the dimensions of the cells inside those BMW hybrid HV packs?

EDIT: I found a post by Celeron55 about BMW module dimensions: "I didn't measure very accurately but a module without BMS is something like 364*183*110mm and the BMS adds about 25mm to length or height depending where you install it."

Power output of MG2 in the original GS450h configuration appears to be 52hp, or 39kW. I got this from specs found on wikipedia here:

"217 kW (291 hp; 295 PS) (GS 450h, gasoline engine only); 256 kW (343 hp; 348 PS) (GS 450h, combined system output)"

Perhaps it's not as simple as subtracting gasoline engine only output from combined system output to get MG2 output. But if it is, then how does MG2 manage to put out 39kW if it is being fed by a boost converter that is (I think) limited to 30kW output?

I believe the combined system output is limited by the different RPMs at which the motors reach peak power.

MG2 can also be fed by MG1, since those DC busses are connected directly together after the boost converter, so MG2 can certainly output more power if you ask for it. Damien's putting lots of power through that one, not sure about the exact power levels but rumors were up to 150kw, maybe 200kw total.

Thans for your reply Isaac96.

So I'm starting to better get my head around this 'hybrid mode' - whilst MG2's inverter is supplied up to 30kW @650v from the boost converter, it draws more juice directly from the rectified output of MG1 at the same time right?

If this is the case, the contribution of MG2 to the 'combined system output' above must be something other than 39kW I guess, since some of the 217kW produced by the gas engine must be 'borrowed' to generate MG1's output, right?

As for the potential output of MG2 or combined MG1 & MG2, I'm not really concerned at present. I'm basically looking for Lexus specs that the L110 is officially contributing to the GS450h so I can tell my engineer the 'stock' electric output of the transmission. Being able to quote an 'official' figure for this should make the compliance process easier.

The combined system power is limited to the engine's max power + whatever extra the battery can provide via MG2.

http://eahart.com/prius/psd/

Same system.

The inverter pretty much acts like an AC-AC converter, of the AC-DC-AC type. Engine rotates the fork in the planetary gear (think "planetary" = open diff, "fork" = input shaft, "ring and sun gear" - output shafts), power goes where there's least resistance - on one end you have the driveshaft, on the other - MG1. The engine rotates, MG1 pushes against it (or regenerates from it) in order to send the power to the wheels. MG2 is connected to the driveshaft via a 2-stage auto (unique to the L110(F) hybrid transmission). A portion of the engine's power goes to the driveshaft mechanically (MG1 "pushing" it to the driveshaft), the other portion goes to the driveshaft via MG2 - itself supplied by energy from MG1.

The powerband in this scenario depends on MG1 & MG2's power ratings at their respective RPMs, and MG1's max RPM - as it is, the GS reaches its maximum engine RPM (6400) at ~140KPH (for EU units with the 3.266 final drive - US & Japan are 3.769, hence faster acceleration). At a standstill, it cannot go past ~3000rpm without overspinning MG1.

Putting the battery in the system nets us +35kw or however much the boost converter can supply extra to the system.

I guess this explains why the motors & inverters in Toyota's hybrid systems seem "overpowered", compared to some (but definitely not all) other makes' hybrid vehicles that pretty much sandwich a small electric motor somewhere in an automatic transmission. If you lock MG1 to the driveshaft (weld, custom reducer, whatever - IMO custom reducer to match MG1 max RPM to MG2 max RPM with MG2 in high gear) and the inverter's stock software doesn't mind, you can probably figure out what can you can achieve

Thanks Lwerewolf. That all makes sense.

I've tried trawling through various topics here on the forums and generally on the internet but still can't find what the official output rating of MG2 is in situ in the GS450h. Do you happen to know where I'd find that information? I'd like to quote a figure, not what it is capable of outside the GS450h but rather I'm looking for what Lexus rate it as in the GS450h application. Paperwork, compliance etc. reasons.

Output rating...
https://media.toyota.co.uk/wp-content/f ... h_spec.pdf
https://media.toyota.co.uk/wp-content/f ... h_spec.pdf
Transmissions are supposedly the same, so it's either the inverter, or the programming, or what it can be fed from the system (i.e. max transferable power from engine & battery combined)... who knows.

Small note - the "10,230rpm limit" of mg2 touted mostly everywhere (and notably in the ORNL article on the ls600h drivetrain) is false, not sure where it originates from. Do the math and check some gs450h/ls600h top speed videos, the number "14,400" might make a bit more sense

Lwerewolf wrote: ↑Sat Oct 17, 2020 7:23 am Output rating...
https://media.toyota.co.uk/wp-content/f ... h_spec.pdf
https://media.toyota.co.uk/wp-content/f ... h_spec.pdf
Transmissions are supposedly the same, so it's either the inverter, or the programming, or what it can be fed from the system (i.e. max transferable power from engine & battery combined)... who knows.

Small note - the "10,230rpm limit" of mg2 touted mostly everywhere (and notably in the ORNL article on the ls600h drivetrain) is false, not sure where it originates from. Do the math and check some gs450h/ls600h top speed videos, the number "14,400" might make a bit more sense

Thanks mate! That factory spec sheet is *exactly* what I was looking for to work with my engineer (compliance etc.)

The lower rpm limit is just weird, thanks for that clarification - 14,400rpm sounds quite realistic.

The maker of the transmission Aisin AW has a page that shows the AWRHT25 (which I assume is the L110 from the GS450h) and the AWRHM50 (which I had thought was in the LS600 but now I wonder if that transmission is in a later high performance Lexus coupe?).

Here is the Aisin AW link: https://www.aisin-aw.co.jp/en/products/ ... up/hv.html

Just googled it, apparently the AWRHM50 was only fitted to the LS500h, so it makes sense that the AWRHT25 with 4WD gear set was fitted to the LS600h.

Reading the specs of the LS600h MG2 output, whilst it uses the same MG2 as the GS450h it makes sense that it would be higher output due to the fact the V-8 makes more power available through MG1 to MG2 in the LS600h, compared with the V-6 in the GS450h. I get it now.

Crikey, those LS500h sell for over $200,000 here in Australia!

I'm sure the AWRHM50 would be a fun gearbox to play with (500Nm torque) but I'd hate to think what it would cost if I was lucky enough to find one for sale. This won't happen however, they seem to be a mostly USA-only model currently. Shame, they have lithium batteries now in the LS500h as well as that 500Nm thumping transmission. USA members look out for salvaged LS500h post-2017 models, wot a grunter!