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Which makes my point that a performance LDU a waste of money and weight...the M3 performance seems like a better choice all around, including physical track width.
A smaller drive unit makes sense, but since the idea is to use the stock suspension, something with the motor behind the axle line fits better than one with the motor in front (like the Model 3 rear unit) - Tesla units with the motor behind the axle would be the small Model S/X induction unit, or the front (not rear) Model 3 drive unit (which has an induction motor), or the related newer Model S front unit. I don't know if there is any hobbyist or aftermarket support for use of these units outside of the OEM installation.

It should be possible to turn the Model 3 rear unit around to run in reverse, as has been done with the original Model S units, but I haven't looked into the details.
 

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Discussion Starter · #24 ·
Ok purchased the ldu today. Also got the axles, gv200 solenoids and the pyro fuse. Anything else I should grab from the donor car? Gas pedal was already gone. Any one using the t2-c controller from ev west?
 

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Thoughts on the lg chem super cells from ev west?
The term "super cells" is bizarre: they're modules (not individual cells) and there's nothing "super" about them. I assume that you are considering the JH3 modules (which LG Chem builds for standby power systems in buildings, not EVs), not the no-longer-available 16S1P modules.

My comments from another thread:
I had not heard of a "JH3" cell or module, so I did a quick search...

An LG Chem catalog suggests that JH3 is the "Energy" (rather than "High Energy" or "Power") variant in their range of cells for large energy storage systems. It may not be intended for use in a vehicle, as it is intended for discharge rates under 1C. Based on this catalog, the 7S 63 Ah JH3 module appears to be one of two used in LG Chem's smallest residential energy storage system, the "48 V" RESU3.3. The other RESU models may use more of the same modules in parallel. The catalog shows that stationary ESS and automotive applications are distinct.

Whether this is the same cell construction as used in EVs or not, the JH3 modules being sold by EV West at 3.22 Wh/USD (or USD $312/kWh) is a 7S (26 V) 63 Ah module; it is not the 16S (60 V) 43 Ah module used in the Chrysler Pacifica, and not even built of the same cells. The Pacifica module is designed to thermal management via a bottom plate, but it is not apparent whether or not there is any thermal management provision in the JH3 module, although the general construction is similar. The JH3 module is a recent addition to the EV West website.


At 63 AH, a 98S pack to run near the 360 V typical of current EVs (and thus suitable if using a Tesla or Nissan motor) would require 14 modules, adding up to 275 lb (125 kg) - plus structure, enclosure, wiring, etc - for 22 kWh. That's a relatively small but usable capacity in a relatively light pack, compared to a complete salvaged EV battery.
 

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Discussion Starter · #29 ·
Wow the negativity is strong in this group. I said from the beginning I鈥檓 building a toy not an electric 1000 mile range yugo with a top speed of 35 to carry the kids to kindergarten. I鈥檓 done with that phase. Thought y鈥檃ll would appreciate something different. I definitely walk to different beat. guess I鈥檓 on my own here.
 

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Wow the negativity is strong in this group. I said from the beginning I鈥檓 building a toy not an electric 1000 mile range yugo with a top speed of 35 to carry the kids to kindergarten. I鈥檓 done with that phase. Thought y鈥檃ll would appreciate something different. I definitely walk to different beat. guess I鈥檓 on my own here.
What "group" negativity?

You got an assessment of a stationary tech being inappropriate for vehicle use. You could just buy them and spend the money, since the answer came from a prolifically posting "troll" that should be limited in the number of replies 馃槀

You also got an answer to your question on high current from me. Along with the cost. You didn't state that weight was a constraint, so you were warned about it.

Lithium is not a high current technology. You asked for high current out of the blue. If you plan to do:

"for sale. VW Beetle. Low miles. Driven by little old lady 1/4 mile at a time", then say so. It's a totally different solution set on the engineering side.

Engineering is not a place for snowflakes. Either man up and take the unbiased information as candidly given, which is what engineers are trained to do, or ignore it and do what you prefer because someone sprinkled sugar on it cuz they have some to ditch on eBay.

If you want high current, lithium's not the best choice, imo. There's no magic lithium chemistry that will give it to you, like you thought you found. Mother Nature doesn't make free sandwiches. Someone pointed that out to you.

My upbringing says to thank the person for their time, research, and OPINION vs whining about its delivery. It also gives everyone a voice and doesn't mob-muzzle valuable contributors just because you don't like their posts, content, or contrarian perspective...in good engineering, contrarian perspective is invited, not shunned.
 

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Old lg cells sure looked like an easy solution. What are people using now for high current draw? Not concerned with range at this point.
Among non-competition automotive applications, the place where high power output relative to battery size (or energy capacity) is needed is in hybrids: they need to put out enough power to drive the vehicle, despite being small.

When the energy capacity required is really small (a classic hybrid that can only move a few blocks on the battery alone) nickel metal-hydride (NiMH) is still viable - Toyota still uses it quite successfully.

When more energy is required, for plug-in hybrids (and the logic would apply to short-range EVs), lithium-ion is used, but in specific electrode chemistries for power density (at the expense of energy density) and with sufficient cooling that it survives. That is a reason for the popularity of Chevrolet Volt batteries in relatively high-performance DIY conversions: in addition to being plentiful, and having been around for a while, a 16 kWh Volt battery can put out 120 kW for at least 10 seconds at a time even by GM's conservative ratings. The LG Chem modules built for the Chrysler Pacifica have been popular as well: plug-in hybrid power capability, and while the Pacifica Hybrid is rare compared to the Volt, the modules (new) were sold by various suppliers. There are other plug-in hybrids, although none are as common as the Volt and none of their modules are as available as the Pacifica modules were.

When the supply of Pacifica modules was cut off, EV West apparently went looking for something else they can buy and found the JH3 modules. They have apparently found them suitable at high C-rates; my concern is that this is not endorsed by LG Chem and this isn't even the ideal choice from among the ESS product line for high discharge rate. Maybe they'll work at repeated sustained high discharge rate, but I'll bet EV West won't warranty them for that.


The other solution is simply to use a big battery. Any cell technology is limited in its discharge rate relative to its capacity, so if you double the battery size you get double the power capability, even though you don't need the energy and don't want the weight or bulk. It's not a coincidence that when two Tesla models have the same motors, if one has higher rated power it also has a bigger battery. You might hope for a Model 3 Performance with the less expensive and lighter standard-size battery, but they know that won't work so they won't sell it to you (and they have more mercenary reasons as well, of course;)).


There have also been companies offering high-power cells for drag racing applications. Maybe they are still operating; they're certainly not relevant to reasonable street-driven EVs.
 

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Discussion Starter · #36 ·
Among non-competition automotive applications, the place where high power output relative to battery size (or energy capacity) is needed is in hybrids: they need to put out enough power to drive the vehicle, despite being small.

When the energy capacity required is really small (a classic hybrid that can only move a few blocks on the battery alone) nickel metal-hydride (NiMH) is still viable - Toyota still uses it quite successfully.

When more energy is required, for plug-in hybrids (and the logic would apply to short-range EVs), lithium-ion is used, but in specific electrode chemistries for power density (at the expense of energy density) and with sufficient cooling that it survives. That is a reason for the popularity of Chevrolet Volt batteries in relatively high-performance DIY conversions: in addition to being plentiful, and having been around for a while, a 16 kWh Volt battery can put out 120 kW for at least 10 seconds at a time even by GM's conservative ratings. The LG Chem modules built for the Chrysler Pacifica have been popular as well: plug-in hybrid power capability, and while the Pacifica Hybrid is rare compared to the Volt, the modules (new) were sold by various suppliers. There are other plug-in hybrids, although none are as common as the Volt and none of their modules are as available as the Pacifica modules were.

When the supply of Pacifica modules was cut off, EV West apparently went looking for something else they can buy and found the JH3 modules. They have apparently found them suitable at high C-rates; my concern is that this is not endorsed by LG Chem and this isn't even the ideal choice from among the ESS product line for high discharge rate. Maybe they'll work at repeated sustained high discharge rate, but I'll bet EV West won't warranty them for that.


The other solution is simply to use a big battery. Any cell technology is limited in its discharge rate relative to its capacity, so if you double the battery size you get double the power capability, even though you don't need the energy and don't want the weight or bulk. It's not a coincidence that when two Tesla models have the same motors, if one has higher rated power it also has a bigger battery. You might hope for a Model 3 Performance with the less expensive and lighter standard-size battery, but they know that won't work so they won't sell it to you (and they have more mercenary reasons as well, of course;)).


There have also been companies offering high-power cells for drag racing applications. Maybe they are still operating; they're certainly not relevant to reasonable street-driven EVs.
Thank you this Brian. As stated this is going to be a toy. I鈥檓 just looking for maximum performance and I鈥檒l adjust the range to suit. I can鈥檛 go crazy and spend $25k on batteries but I鈥檓 not afraid to buy what I need to make it what I want it to be. Obviously I won鈥檛 be able to put the torque from this Tesla sport ldu to the ground right off the line and I鈥檓 not trying. Nothing would make me happier than to need new rear tires after a long weekend. 馃榾 I鈥檓 really here because I just don鈥檛 know what direction to go. I like the idea of liquid cooling but that comes with a cost mostly added weight that being said I also want to be able to make the 20 mile drive into town mostly open road 55mph, have some fun and come home. I certainly could charge in town if needed. Thanks
 
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