Sorry it’s been ages. My job got DOGE’d so things have been hectic. Moving to Seattle soon, and going to button the Bug up and tow it.

It’s getting there, though. Refitted the seats in to make sure they clear the batteries:
IMG_7283.jpeg

And building the battery covers out of 16-ga to protect ...

Successes so far:

- The Guition JC3248W535 display is the most mature now. So far I have been able to:
1) Generate graphics including improved fonts and BMPs for various warning indicators.
2) Touchscreen working but haven't done anything with it yet
3) Built a full simulation Serial interface ...

hmm, I think no version of the gerber files had serious issues. The ESP32 module is challenging to solder, especially the heat transfer pad. Are you sure that is making good contact to direct the heat into the PCB and away from the chip?


The heat transfer pad is also a ground, yes? Having a ...

I've been experimenting with "cheap" displays from AliExpress, with the intent of running user interface / display off of them in my Beetle project.

The display I have started with is the Guition JC3248W535 display. This is the cheapest display at <$20. It is defined as a 320 x 480 pixel 3.5" TFT ...

I have completed my front battery heat exchanger. Again caveat is that my main concern is balancing temperatures. I am not DC fast charging, but regardless I've done thermo calculations in Autodesk and I should be able to dissipate 2000 Watts of heat with the following design, even with the not ...

There are a hundred small things that I am working on that I want to provide an update to. I am finishing the mounting and wiring of the batteries, the Thunderstruck MCU (BMS, charging, and battery indication), building the cooling plates, working on CAN Bus design, control, and indication, and 3D ...

If the cables are shielded, they should not induce voltage on the pipes. And if they did, you would not want that stray voltage going to ground, because that will generate EMI on your 12v circuits which are grounded.

You can leave them ungrounded, or even better just electrically tie the ends to ...

Time to announce an answer to the question: Can the MCU run the Mercedes BMS satellites?

YES.

Here's what you need to know. First, make sure you follow all the Thunderstruck MCU instructions. You need to set up a serial communication port using PuTTY, configure it correctly, then, at a minimum ...

Here is the off-the-shelf EMPI axle shaft. That, the CVs. boots, grease, flanges, and bolts... (Which in retrospect it would have been easier to buy the whole kit but I didn't know what length I needed when I started this thing and thought it might need to be custom machined)

axle_1.jpg


The ...

Counter leaverd off the one side of the frame horns with a flat metal interface won’t be strong enough.


All motor mounts are cantilevered if you think about it.

I ran the mount design through SolidWorks and it is plenty strong. The highest stress point is right on the face of the M18 bolt. Now ...

Daveturpin wrote: ↑Mon Dec 23, 2024 3:14 pmAnd the Model 3 radiator fit overhead. Unfortunately this block off the fill hole for coolant.

Just thinking about this a teeny bit more, in order to get the coolant system filled, I either need to locate the radiator further down, or extend the fill hole further up...

Christmas update!

I have been finishing up a lot of the fab work, doing final fitting on the batteries, etc. Here is the SDU reinstalled for the first time since the suspension was redone:
SDU.jpg

Here are the locations of the non-motor electricals mocked up. Thunderstruck charger and Elcon DCDC ...

Steel, cold rolled, 20 gauge. The front box is reinforced with steel bar and the pan batteries are reinforced by the structure of the floor pans. Bolts go into nut rivets for strength. There will be covers made out of a non-conducting material, like fiberglass.

Edit: I originally put 16ga, it is ...

Following, this task is one of the next things I need to do on my project.

I have CATL prismatic cells, which are cooled conductively in the Mercedes EQ they came from with what, in my opinion, is a bit of overkill. Like it was said above they probably don't need MUCH cooling.

I built the battery ...

Update 11/4/24:

I am very close to getting the basic stuff done. Battery boxes complete, brakes rebuilt, accelerator pedal done. I at least have ON HAND most of the rest of the pieces: Contactors, 12v battery, DCDC converter, Thunderstruck MCU (BMS and Charging) and a 3kW charger. Have the 00-gauge ...

I used a gen 1 Chevy Volt dc/dc which is rated for the voltage and has easily controlled, adjustable output voltage. For me it's also a plus that it's air cooled since I didn't want to deal with running water lines to it. If you are also using a Thunderstruck MCU, it has a setting for it. Just ...

Maybe I just wasn't looking hard enough... Thanks again, Tom.

I'll give the OEM units a check.

I just feel like I'm missing something fundamental here. Presumably every single EV conversion needs a DCDC converter. But except for the very pricey EVWest unit, it doesn't seem like aftermarket companies have given it much thought, and where they have, the DCDC ...

Let me caveat that I am using a Thunderstruck charger and need a separate DC/DC converter…

I found something with the right specs… but it’s more of a laboratory-style package. Anyone use something like this, possibly in a custom enclosure? (It does say EV is a typical application)

https://www ...

I’m in the process of finalizing the install and wiring routing in my Beetle. Trying to figure out the 12v system.

I’m not finding a DC/DC converter that matches my pack, which is 90s1p (288-378v) total. I do see generic converters that would work with single module 18s1p (58-76v) or two modules ...

IMG_6633.jpeg IMG_6632.jpeg

Some updates!

I finally actually installed the openinverter SDU v.8 card, which was assembled and given initial setup by Westside EV www.westside-ev.com . Now I finally understand the “try to desolder the Tesla current sensors and if you f it up use new ones”. Yeah, I ...

So you are finding so far what I said is true.

Good to know Mercedes have not opted to try and lock down their BMS for no real reason what so ever.


Yes, and I am very appreciative of the help you are giving me. When I talked to Thunderstuck, though, they recommended against using their MCU ...

More progress! So, long story short. The "Quickeval" software and DC590 board does NOT work with the LTC6813 18-cell monitor.

So I tried using an Arduino Uno to read the cell voltages directly. That doesn't work, without building a separate LTC6813 circuit for isoSPI to SPI conversion.

Finally I ...

I had considered using the onboard charging capability in the openInverter card, but here is why I decided against it:

1) You still need a BMS, and there are fairly inexpensive solutions for BMS and charging on the same hardware.
2) What EVSE are you using? If you are using a J1772 (CCS A/C ...

Okay, just spitballing here, but I know the EQ battery BMS communicates with isoSPI protocol. It looks similar to, but is NOT the same as CAN.

Your best bet would be to use a larger EQ battery instead of trying to swap protocols?