(Driving) Tesla SDU in Fiat X19

[phillipschip]

I thought I'd share what I have done so far with my project. I have the motor mounted and am now moving on to the axles.
I am planning on having the Tesla Axles that I have, cut and splined for the Fiat CV outers. The Fiat uses two of the same CV setups for both the inner and outer, so when mounted, the axle has lateral movement (in and out). Seems different from the typical setup with the outer fixed and the inner to allow that type of movement. I guess I just need to measure carefully in the longest position so it isn't too short causing the risk of pulling out the diff end :0

[phillipschip]

I should probably move this to “projects”

[Bratitude]

being rwd, they are doj, double offset joints. a cv on the outer end is not needed as the rear wheels dont do steering.

youll want to measure with the wheel and the driveunit lined up perfectly, full compression of the inner cv races.

[phillipschip]

Driveshafts arrive today! I got the engine bay painted, now on to the 10 battery modules. Only 9 more to go!

[phillipschip]

Axles are in.

[phillipschip]

Interior painted and ready for some wires.
All new brakes and master cylinder done too.
Bleeding brakes in a completely dry brake system was very challenging with this car!

[tom91]

What angle is the gearbox heat exchanger? The pictures make the angle look quite serveer.

[phillipschip]

It is slightly tilted forward, but the oil pickup inside the diff is still at the bottom. I might just not be able to drain all old fluid without a pump.
I came to the conclusion that it would be fine: viewtopic.php?p=73331#p73331

[phillipschip]

Working on the battery boxes. One in the rear somewhere and one in the “frunk”

[phillipschip]

Got some work done. Decided to redo and go with polycarbonate boxes instead of the aluminum-the metal scared me :0
Almost done with both boxes and contractor box is complete. Each 39/40v module (10 total) will have charging/balancing through its own bms, temperature sensor relays (hooked to fans) and low voltage alarms for individual cell groups.

[phillipschip]

Question about dc-dc converter. I have + and - wires off of each of my 10 36v modules for charging. I was thinking about just wiring off of these in parallel and using a 36v-12v dc-dc converter for my accessories. Total amp draw with everything on would be less than 10a. Is that a silly idea?

[Proton]

If they are in series then it would not work. You would short them.

[phillipschip]

I'm confused as to what would short. Within each battery box I have 5 36v modules in series. I also have a + and - charging wire off of each module. If I just combined all the + and all the - wires in parallel for the converter to draw off the entire pack wouldn't that work?

[2fast4u]

I assume you have the modules connected in series to get enough voltage for the drive unit? Do you intend to rearrange the battery packs to a parallell configuration each time you need to use your 12v supply? You cant have the batteries connected in series and parallell at the same time unless your intention is to let the smoke out.

[phillipschip]

Yes, that makes sense. I could have figured that one out pretty easily had I drawn it out :0 I guess there would be no way to combine the draw of a 36v to 12v dc-dc across the whole pack. It might work to combine every other one in parallel? 3 out of 5? Otherwise, back to looking for an affordable 400v-12v then, or just using a larger 12v battery and charging every time I plug in and charge HV.

[Proton]

If you just want to test you can get something cheap like this one. It an only put out 55W at max.


https://www.aliexpress.us/item/32568050 ... pt=glo2usa

or this one: 750W

https://www.aliexpress.us/item/32568047 ... pt=glo2usa <-------------------

not sure how efficient they are.

[phillipschip]

I was looking at getting one of these, or one for each battery box-$19 and 240watts on Amazon:
Can't get the link to display

[Proton]

What is the reason you want to have one for each module? it does not make sense.
You need just one 400v to 12v.

[phillipschip]

Yeah, if I had a 400-12v I'd only use one. I was thinking two if them if I used 36-12v.

[phillipschip]

They look like this.
My build is kind of a hotrod grocery getter, drag racing as an option deal. I wouldn't be driving more than 20- 30min on a charge (about a 30 mile range) so would be plugged in most of the time. I figured I could use one of these 36-12v dc-dc converters tapped into 3 out of 5 of my modules.

[Romale]

.... I figured I could use one of these 36-12v dc-dc converters tapped into 3 out of 5 of my modules.

I still can't understand why you don't take a very cheap affordable pdm from Nissan leaf gen 1, opening it you will get 4 contactors and one compact dc/dc for one and a half kW output, gives ideally 14 volts, works from 150 to 420 volts at the input and starts simply by applying +12 to one pin.

[Romale]

viewtopic.php?t=1532

[phillipschip]

That sounds like a good idea. I didn't know about that option. I'll look into that.

[phillipschip]

What is the weight and price on that Leaf unit? I'm looking for something light and cheap-I have very few accessories that need 12v. My build is kind of a grocery getting electric hotrod weekend at the track type of deal. I didn't have much luck with a brief check on eBay. I searched for "Nissan Leaf first generation pdm".

[Romale]

In Russia, its price is no more than $ 30. I do not know about you. here is the part number to search for and the appearance.