openinverter forum

Since im working on a vw t3 with tesla sdu I was wondering what would be the minimum amount of tesla batteries to use. Are you still planning a 8+4 module setup? Or with the higher capacity p100 modules only 8 under the floor?

In my t3 I can fit 2 layers of 5 modules under the floor without cutting in the chassis by making one battery box. Im only doubting if 10 modules would be sufficient to run the SDU efficiently. At almost empty it would be around 200V.

Also for CCS charging. All sockets I find have a 200amp max. With 10 modules this would be 50kwh fast charging. A bit faster would be nice.....

Thx for your thoughts and nice progress!

larsrengersen wrote: ↑Sun Feb 02, 2020 1:50 pm Do the colors imply you have a in/out (assuming cooling)?

Correct... it just helps us identify what's going where when we have so little space.

larsrengersen wrote: ↑Sun Feb 02, 2020 1:50 pm I was expecting counter flow for better heat exchange.

We're very constrained by the space available in the belly battery box. We took a view that we could easily cool a battery with a single small motor running at ~280V when the original system was designed for a dual motor ludicrous at ~350V

tmotion wrote: ↑Sun Feb 02, 2020 3:59 pmAre you still planning a 8+4 module setup?

Yes, 50kWh in the belly battery box and 25kWh in the rear battery box.

tmotion wrote: ↑Sun Feb 02, 2020 3:59 pmAt almost empty it would be around 200V.

You may have issues with top road speed at this voltage. I don't know anyone who's tested the SDU on the road at that voltage.

If you only want to use a small number of modules then consider modifying them to ~50V each.

tmotion wrote: ↑Sun Feb 02, 2020 3:59 pmAlso for CCS charging. All sockets I find have a 200amp max. With 10 modules this would be 50kwh fast charging. A bit faster would be nice.....

We know the Tesla Model 3 CCS connector is being used to charge the Model 3 at 250kW which is ~700A at 350V

That said, if you're down around 200V you may find CCS does not work (the spec says it should but AFAIK it's never been tested) and we also know that most CHAdeMO chargers don't work at this voltage (see Damien/EVTV testing).

Thanks! You confirmed my doubts. I like to have a belly batterybox in the centerline of the van. Of course i have plenty of space next to it, but also from a side collissiin safety point of view I prefer not to have additional batterymodules on the edge of the impact zone.

I’ll do some additional measuring where to fit the other 4. Just like you in the former engine compartment will probably be best.

Looking forward seeing this bus in June during the ev course!

tmotion wrote: ↑Mon Feb 03, 2020 6:18 pm I’ll do some additional measuring where to fit the other 4. Just like you in the former engine compartment will probably be best.

Have a look at fitting four of the shorter Model 3 Battery Modules in the central cavity. It may be possible if you're undertaking chassis upgrades. Please start a project thread if you'd like to discuss this further.

tmotion wrote: ↑Mon Feb 03, 2020 6:18 pm Looking forward seeing this bus in June during the ev course!

Great, we can go for a ride in the bus

I hv just found your thread in https://www.diyelectriccar.com/forums/s ... 89p11.html
Learn so much from it.

Thank you very much.

r12410 wrote: ↑Wed Feb 19, 2020 12:45 pm I hv just found your thread in https://www.diyelectriccar.com/forums/s ... 89p11.html
Learn so much from it.

Thank you very much.

I'm glad you like it, has been a fun project

I am planning to convert a classic mini pickup with tesla's SDU and Damien's logic board

Do you have tips for me?

r12410 wrote: ↑Thu Feb 20, 2020 2:02 pm Do you have tips for me?

Read the forum and wiki

ok
thx

Kevin Sharpe wrote: ↑Thu Feb 20, 2020 6:35 pm

r12410 wrote: ↑Thu Feb 20, 2020 2:02 pm Do you have tips for me?

Read the forum and wiki

I recently loaded the Tesla modules into the 'belly' battery box and spun up SimpBMS. Impressive to see that after two years on the shelf the difference between high and low cells on 8 modules is 8mV

Had some fun modifying the Tesla Model 3 HV connector ready for final assembly of the "belly" battery

Happy to report you can anneal and straighten the ~4mm copper without damaging the 'tin' surface used in the connector wiper area.

I've been experimenting with terminating the screens on Tesla HV cables.

For the 35mm2 SDU cables I used three ferrels which had the screen braid sandwiched between them. This sandwich was gently crimped with a 95mm2 die (being careful not to damage the insulation of the central HV cable) and then heat shrink was applied to both ends to make the assembly look neat. The end result makes a good electrical connection to the screen and fits nicely in the Tesla HVJB.

When I get time I'll try some of the larger Tesla cables.

How is the screen itself terminated to ground? Via the glands?

Where did you source the model3 HV connector?

JaniK wrote: ↑Tue Aug 25, 2020 4:55 pm Where did you source the model3 HV connector?

Wherever they are cheap

So its used then..? Have to ask around

JaniK wrote: ↑Tue Aug 25, 2020 5:12 pm So its used then..? Have to ask around

If you search for eBay vendors who are selling the Tesla Model 3 PCS you will often find they are selling the HV connectors;

Here's the motor connector for 70 USD;

https://www.ebay.com/itm/Tesla-Model-3- ... 3686667523

And rapid charging connector for 170 USD;

https://www.ebay.com/itm/2017-2019-Tesl ... 4029399114

DaveH wrote: ↑Tue Aug 25, 2020 4:40 pm How is the screen itself terminated to ground? Via the glands?

The glands are clamped into the Tesla HVJB just like the original cables.

been following the build, i cannot determine how the 2 packs are connected together and what BMC is being used to guarantee balance between the two packs during charge/discharge. can someone point me to the post that has this information?
I've have been restoring a 78; thinking about retrofitting a tesla power-train similar to this thread; I looked at EVWest and their kit consists of a 96V controller https://www.evwest.com/catalog/product_ ... 34c5b3d93e. i'd like to maximize range, and was thinking about using a parallel battery pack modules to keep at 96, but from what i've read, its not a recommended/safe arrangement...

Kevin will most likely not answer, he's not active in the community anymore.