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So the 750 A and 500 A current values, despite being shown with battery voltages, are likely RMS motor currents for the S2 (short time duty) condition with two-minute duration.
Thanks @brian for all the sleuthing, which all makes perfect sense. In particular, the bolded above, is very helpful - the ACX1 manual and data sheets I have seen often referred to things like 'max power(2')' or 'Max RMS (2')' - I didn't know what the 2' meant but now, having looked up S2, it makes sense.

So now we know what the specs are saying ... still don't know how to limit the current the controller can pull from my pack!
 

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I too am scratching my head over this motor. I'm in the preliminary design phase for a 98 Wrangler conversion and am trying to size my battery pack and wiring, but can't get a sense of the number of continuous DC amps I should be expecting the controller to pull. Anyone worked this out yet? Trying to find the right cables and connectors by amp rating.
 

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I too am scratching my head over this motor. I'm in the preliminary design phase for a 98 Wrangler conversion and am trying to size my battery pack and wiring, but can't get a sense of the number of continuous DC amps I should be expecting the controller to pull. Anyone worked this out yet? Trying to find the right cables and connectors by amp rating.
Well, all in all I'd say the motor is good and the controller, whilst it has some foibles, is also good. It has its own precharge circuitry which is one less thing to worry about. I use the low voltage version, with 5 Tesla packs.

I am running a VW Beetle so a pretty light car and I very rarely run more than 300A DC continuous - what tends to happen is you pull maybe up to 300A briefly when accelerating away, depending on how heavy your foot is, and then once you are up to speed the current draw is much lower (as you fight wind and rolling resistance). The motor itself I think is rated for 350A ish continuous. I use 70mm2 cabling for the HV throughout (00 AWG), and you could probably get away with 50mm2 if you weren't going to hammer the power.

Not a very scientific answer but in short, use 00 AWG, and you'll be fine ...
 

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Look up the specs on resistance per foot on your cables, multiply that by an arbitrary 300 amps and see what the voltage drop is per foot. Volt cars use about a 2awg flat strip and get a decent resultant power reduction. If that matters then you need thicker cables, if it doesnt use whatever you want that won't melt under maximum power. 2 awg is fine for 50 hp volksies, but sucks in a 300 hp Camaro
 

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I'm running aluminium power cable for the long (>1metre) run from my X1 to battery pack. 500kcmil which is just over 250mm² ! It's still lighter and cheaper than Copper for the equivalent voltage drop though. I'm probably going to use aluminium bus bars in the pack for the same reason.
 

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Aluminum wire and bus will crack and eventually break under vibration. It is not the best choice for an EV. Go with what the masses are doing...
 

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Aluminum wire and bus will crack and eventually break under vibration. It is not the best choice for an EV. Go with what the masses are doing...
Hmmm... maybe someone should tell Tesla that. ;) The Plaid pack has aluminum bar conductors which extend the entire length of the pack, plus shorter aluminum bar conductors connecting components at the front end.
Model S Plaid Battery Tear-down video

I agree that cracking due to vibration is a concern, and needs to be considered in the alloy selection and mechanical design of aluminum conductors.
 

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Are you endorsing his use of aluminum wire?

Brian, You seem to enjoy playing the guru role. You should be more careful with your words to the general DIY hobbyists. This is a DIY forum and has no relevance whatsoever to a Tesla engineered pack. What basis did you conclude that the connection bars are aluminum? They look like tinned copper to me.

Again, this is a DIY community and "we" should be steering builders to the materials and methods that most can successfully accomplish at home.
 

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Aluminum wire and bus will crack and eventually break under vibration. It is not the best choice for an EV. Go with what the masses are doing...
The cross section of each individual strand in that power cable is several mm², likewise the bus bars are about 8mm x 20mm section! Neither of them are going to be cracking under vibration. I accept that I have 11 years as an automotive OEM Powertrain Design Engineer and therefore access to material and processes that the average DIY home enthusiast does not. But to be fair I have never advocated anything to anyone, simply sharing how I am going about things on my project for other people's interest and consideration.
 

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Are you endorsing his use of aluminum wire?
No, I didn't say that at all.

You should be more careful with your words to the general DIY hobbyists. This is a DIY forum and has no relevance whatsoever to a Tesla engineered pack.
This forum has huge relevance to those packs; DIY hobbyists discussing their projects in this forum routinely use Tesla modules outside of that pack, taking on the responsibility for duplicating the features and capabilities of the Tesla OEM pack... usually with vastly inferior results (for enclosure strength, for instance), which seems to be okay with almost everyone in the forum.

What basis did you conclude that the connection bars are aluminum? They look like tinned copper to me.
They just appear to have too much cross-sectional area to be copper, and it makes little sense to tin the entire length of a conductor bar instead of covering it with insulation. This would be a continuation of Tesla's long-established use of aluminum conductors, as module bus plates and in stranded cables. But I may be mistaken; after all, the aluminum rotor bars of Tesla's original induction motors have been superseded by copper bars in the current generation of Tesla induction motors. I assume that no one would be stupid enough to use a random bar of aluminum just because a OEM apparently used a different bar of aluminum.

Regardless of the material used by Tesla, I advised that "cracking due to vibration is a concern, and needs to be considered in the alloy selection and mechanical design of aluminum conductors." If someone doesn't know how to handle those considerations, they should not use aluminum.

Of course, similar concerns exist with copper, but apparently we're assuming that DIYers have a sound understanding of the conductivity of the various classes of copper alloys and the properties of those alloys with respect to fatigue strength. :ROFLMAO: In fact, the average builder assumes that all "copper" is the same, so a crushed copper water pipe makes an ideal conductor... and it might - I don't know. :)

Again, this is a DIY community and "we" should be steering builders to the materials and methods that most can successfully accomplish at home.
Absolutely true... and the only design of EV which every DIYer is qualified to build is the one that is purchased new from a car dealership, for which the "build" is the order sheet. ;)
At the very least, the assumed morons of the DIY world should be restricted to using commercially fabricated cable assemblies, right? Oh, right... they're allowed to select conductors, and to select and install connectors on them, but not to select conductor material.... hmmmm.

Many builders in this forum have never welded, but it is okay to discuss welding structures. Maybe we should be steering builders to only bolting stuff together, since most cannot successfully accomplish the fabrication of welded structures at home? No.


I do understand the idea of promoting technology which is appropriate for the user. As an example from another subject area of online discussion (not EVs), many commercial trailer frames are built in aluminum, but I shudder at amatuer plans to use aluminum; they are likely safer to stick to mild steel. What I don't do is declare that no one should discuss the possibility of using aluminum for that application.
 
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