openinverter forum

I do not know what works for you mechanically, but for uniform temperature along the cooling element, I would make a Y-pipe to connect the inlet to the two outer extrusion cavities and then route the coolant with another Y-pipe to the center and back. This way the cold inlet flow will "mix" with the hot return flow and result in a very small temperature gradient along the element.

Yeah I think I need to experiment with it.
The coolest option is one side in 3x en other side 3x out.

This tunnel pack will be 2x5 modules and a smaller plate of 2 at the front. 12 modules total. Good for 33.6kwh.

"I finished" the smaller plate and refined the construction process...

P.s. not my best welding while experimenting with the settings, but it's water tight.

In orde to know the space I have in the tunnel for the pack. I bit the bullit and bought a front engine too.
Will they say YES to each other?!?
Who called who?

Big puzzel; yesterday cut of some foam to get an idea about size and fitments. To ditch the AWD or not ditch it.

Would one SDU be capable anyway todo 120km/h continuously?

From a quick 'google' the continuous power of the SDU is 35kw. (47hp in the ICE part of my brain)
Not sure that would be enough for cruise in a big car like the Panamera if you encounter some long hills?
Don't know if that's just a limitation of the Tesla cooling system? combined with lack of air intakes for the radiators?

Thank u for thinking allong, that's exactly my fear too.
Heat saturation. So I will try to mount as much batteries in there as I can

The SDU is an induction motor isn't it - so I believe there is more a fundamental limit/difficulty on removing heat from the spinning rotor, PM motors tend to heat their stators so its much easier to remove heat from these.

Continous power isn't relevant for EV use, except on the race track. I wouldn't worry too much here and see what practise says as even prolonged stretches will end after some minutes

A quick calculation gives me a required continuous power of 30,2kw to maintain 120kmh. Assuming a cvalue of 0.3. Was not able to find actual c value of the panamera.

johu wrote: ↑Tue Apr 19, 2022 11:21 am Continous power isn't relevant for EV use, except on the race track. I wouldn't worry too much here and see what practise says as even prolonged stretches will end after some minutes

Maybe that's why most EV's aren't rated for towing - or when they are they can only tow light trailers? because they might run into thermal issues and restricted power?

SuperV8 wrote: ↑Wed Apr 20, 2022 2:29 pm Maybe that's why most EV's aren't rated for towing - or when they are they can only tow light trailers? because they might run into thermal issues and restricted power?

You're probably right, especially since stronger AWD versions of the same car can tow more.
So I could extend the above and say "except you're on a racetrack or towing" (or towing on a race track)

Thank u guys for giving this some thoughts. I'm gonna try if i can get 90kwh squeezed into the panamera if i can i will proceed with AWD. If i can't i will take it out and go RWD only. it means 32 modules of 150x110x390mm. Or 2 packs of 16modules, each module = 6S2P.

If i cant get enough battery in there its not completely worth the effort to have dual-motor. If i can squeeze it in i have atleast the amps range and experimenting will then decide if i stay AWD or not.

@tmotion; Cd of 0.3 isn't to far off if i remember i got 0.29; The weight of the car is another thing its very heavy...

Ok I think i can get it in. Currently working on the pack which will reside in the tunnel and partly under the rear seatings. It's super mega tight and allot of work!

I pressure tested all channels to 4bar air. No micro bubbles anymore..

Might add some pictures later.

How do we make busbars? TIG Welding copper? Or do we go alloy?
Or just solder the copper bars?

Especially the long ones (800mm)? Heatshrink? Adding PVC strips?
(for extra protection?)

Which size should I use? 25x5mm?