openinverter forum

Hello.
I thought I would start a build thread for my project. We have two Lexus GS450h in our household, 1 running 2009, and a dead 2006. I bought them both as non-runners from Copart. I managed to get the 2009 running by replacing the HV inverter, then I got carried away and bought another one, which I rebuilt the hybrid battery on, but it turns out the engine had slipped timing and a few cylinders have no compression. The plan is to remove the ICE, and install a battery pack along with a zombiverter. I am an electronics engineer by trade, so I have a tentative plan to re-layout the PCB so it can be fitted in-place in the existing Lexus wiring loom, by soldering a new PCB in place of the old one in the original Hybrid ECM. Attached is a picture of the fossil eating dinosaur.
With the engine out I should have approximately a volume 70cm x 70cm x 45cm tall. What are my battery options?

Seems like you could fit 10 Tesla Model S modules in that space. Could give you 40+ kWh. Even more if you want to add some to the trunk or where the gas tank is.

PatrcioEV-ATX wrote: ↑Tue Sep 12, 2023 3:49 pm Seems like you could fit 10 Tesla Model S modules in that space. Could give you 40+ kWh. Even more if you want to add some to the trunk or where the gas tank is.

Yes, that is one option, but will likely cost me £7000 to go that route. There is also BMW i3 modules, 6 of them would give me 36kWh and be around £3k. I wish I could fit the B250e modules in, they are even cheaper.
Now do I get the Lexus GS450h VCU or the Zombiverter ?

Project update: Just ordered a "Lexus GS450h VCU V1.0" from EVBMW.

Can you elaborate why not "just" the zombieverter? It is stated on the inverter's wiki page that gs450h board is outdated.

0tik wrote: ↑Wed Sep 13, 2023 11:54 am Can you elaborate why not "just" the zombieverter? It is stated on the inverter's wiki page that gs450h board is outdated.

Oh no, did I order the wrong one?

hazelnut wrote: ↑Wed Sep 13, 2023 1:17 pm Oh no, did I order the wrong one?

The GS450h VCU will work just fine. You don't have as many general purpose in/outs, but you're likely going to customize the code no matter what you choose.

I really want Tesla 4.3kWh packs, because they are simpler to cool. But I only have budget for 9. Does this even sound feasible? The pack Voltage would be around 225V.

I guess you'll be around stock Lexus voltage so using the inverters boost stage would provide full speed but not a massive amount of power as I understand. However, if you're geared correctly, it will spin at that voltage with a direct connection to the DC bus (eliminating the boost stage) but could be down on speed.

Jacobsmess wrote: ↑Tue Sep 26, 2023 7:19 am I guess you'll be around stock Lexus voltage so using the inverters boost stage would provide full speed but not a massive amount of power as I understand. However, if you're geared correctly, it will spin at that voltage with a direct connection to the DC bus (eliminating the boost stage) but could be down on speed.

I assumed I would have to bypass the buck/boost stage, but is the ZombiVerter able to switch on the booster ? Hope to collect some modules tomorrow if all goes well.

hazelnut wrote: ↑Tue Sep 26, 2023 6:43 pm I assumed I would have to bypass the buck/boost stage, but is the ZombiVerter able to switch on the booster ? Hope to collect some modules tomorrow if all goes well.

As I understand the boost stage is bypassed due to the high voltage battery of 400v or so. If you're down at 200v then there is no need to and it means you can still get max rpm from the motor which won't be possible if bypassing the boost stage.... at least that's as I've understood it.

I think in the normal zombie setup, the boost stage is bypassed altogether and is not used.

As mentioned in one of damiens videos, using the boost converter will work for slow speed with zombie, but if you try to use it at higher speeds you be left stranded and with a dead inverter. I think it's this one

Update - ZombieVerter arrived. So things to do include:
1) remove the fossil-burner boat anchor
2) Decide on batteries and purchase them.
3) Wire it up.
It is my understanding I will need a battery voltage >> 200V to run bypassing the boost stage on the inverter. Ideally 650V. This pretty much rules out using Tesla 18650 modules. So what are my options here? I can't find a detailed thread about this. Surely this is a common issue for GS450h conversions?
I'm happy to go 20->40kWh around 200kg.

Essentially the Lexus motors have been shown to run at between 60-650V...
On the oak ridge report they found the inverter to be most efficient at 230V where the boost stage is not boosting. By passing the boost stage allows you to still run the transmission but unless you have a 650V battery pack (unlikely) you will be below max rpm.
From what I've seen and gathered, the motors run at around 25rpm/V.

This, should provide you with guidance, however given the GS450H has two gears (1.9 and 3.9) you can probably not worry too much.

Run your tyre size/diff gear ratio and gs450H gear ratio through a speed calculator (I like the boosttown one) and it will give you your top speed. Max rpm of the engine will be based on the voltage you can feed from your battery but if you repurpose an OEM EV pack around 350-400V you should be fine.

My GS450H powered Omega ran just fine with 9 Tesla modules before I added the rest of the 13 modules that I had already bought and planned to install. One reason for 13 was to get lots of range and DC fast charging speed; the other reason was to get the voltage up there where all DC fast chargers will co-operate. Some CCS chargers won't like <200V.

If you're installing all 9 under the hood, consider the weight also. I replaced a V6 with those 9 initially, and it was too much. Now I have 6 rear 7 front which is nice.

pulling up a chair and grabbing a cold one for this one