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Discussion Starter · #1 ·
Hello Group,

I recently acquired a flooded Delorean and am rebuilding from the frame up, the engine looks like a rusted bucket of mush as is the transmission rusty and seized. Fortunately the body is in good shape and I have a not wiring harness though I might rewire the 12 V system with a painless wiring harness. I am planning on building it back as an EV and I would like a few recommendations. Ideally id like a mild increase in power from stock and range of ~100 miles, I was planning on going with small Tesla rear drive unit for a motor and 14 Tesla battery modules and was considering a kit from 057 or stealth EV. My understanding is 14 modules would be the minimum to get the voltage needed for the Tesla drive unit. I know of 2 people that have used the Tesla drive unit and I have a lead on driveshafts and mounts for this setup The difficulty with this is I would have to cut a lot of the stock fiberglass to fit modules in the Delorean frunk and likely relocate the brake booster, this would be all manageable, but the weight addition is substantial. I am open to other drive train options, but since my transmission is hosed I would likely have to buy a new transmission for anything that is not direct drive which condidering the power loss with using a transmission seems foolish no?

Has anyone had success with different battery options for a Tesla drive unit? I had one company suggest NMC prismatic cells, but It seems like I would have to fashion cooling plates myself which seems much more difficult that using Tesla modules and purchasing boxes for them. I was really excited about the specs from electric GT's oxo battery modules, but I just called them and they won't sell anything that's not a complete kit.

thanks
 

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A hyper 9 hv with 7 tesla modules would be a mild increase in power and get you 100+ miles of range. With 14 modules you'll be spending more than you need to, plus you'll still need to find a way to make them fit. Of course a transmission is also needed with the hyper 9. It's also a lot lighter as the hyper 9 is only 120lbs versus over 200lbs for the smallest Tesla drive unit available. Also substantial weight savings with 7 less modules at 55lbs each.
 

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These are the battery modules im planning on using in my build, I have a small tesla drive unit in my car too.

I'll be using 24 modules in series for a 400v 50kwh battery, should give me 280 or so kms range. Im reshaping the transmission tunnel of my car to take the full battery pack, but they are modular and have a cooling plate that you can mount them to. Something like this may work for you?
Essentially you just need a battery that has enough voltage and enough ability to flow amps to supply that SDU. they will run on a lower voltage and power too, you just dont get as much power or top speed out of it, so that could be a compromise your willing to work with if you could only fit 20 of those batteries for example. There is also a 6S2P version of that module, so you only need 16 of them to make a full battery, you dont get as much power or range off the full battery
 

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Those modules are a good option if the voltage with Tesla modules won't add up to what you need, but since he's shooting for only 100 miles of range and moderate performance, I think he could would be better off with tesla modules (cheaper and more power dense than those CALB modules) and a hyper 9. A full tesla swap (full tesla pack and complete drive unit) is typically for the high-performance, high range, conversions where cost is also not a primary concern.

For your use case those modules definitely make sense though as you're looking to run a Tesla SDU.
 

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The tesla drive train does have decent performance, as does a hyper 9 with enough voltage. But why make a golf cart? Why purposefully go with an inferior option if you don't have to? When you add up all the bits required, the tesla motor is about the same as the warp 9. The warp 9 is just simpler to mount, that's all.

The biggest 3 advantages to choosing a tesla drive unit?
1. Its made by an OEM company with millions in R&D and millions of units on the road. This should almost guarantee trouble free driving for years to come.
2. The voltage is high enough that incorporating DC fast charging into the whole system is feasible. This should make it possible to take the car on long trips wherever you want.
3. The whole unit is compact. This is a bit of a double edges sword though, because you have to use independent suspension, no live axles.
The big advantage with it all being compact is the inverter and gear reduction is built in. No bulky heavy transmission that you'll only use 2, maybe 3 gears of. More space to fit batteries low in the transmission tunnel, also room for the contactors and main fuse between the battery and motor in the transmission tunnel. If it was a front engine rear wheel drive car, there is the whole engine bay to fit batteries. you can keep the overall weight balance of the vehicle right if the battery is where the engine used to be.

The biggest challenge is going to be working around that awkward shaped backbone chassis.
 

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Some counter-points:

1. Cost. You'll end up spending a lot more for a conversion based around a Tesla SDU, mostly because of the battery voltage requirements which severely restricts your options for using OEM modules (unless you want to reuse the whole pack).

2. DCFC is feasible on a hardware level but we are far from having a large number of DCFC-capable conversions. The cooling required for DCFC is also a significant hurdle: Tesla uses a heat-exchanging block in conjunction with the air conditioning system. This is not easily replicable in a conversion. Plus the software compatibility with DCFC stations isn't available for conversions (at least in the US, Zero EV has a CCS2 kit for chargers in Europe, although it is sold out and costs $4k). And I think that the DCFC station providers will try to cut off conversions from using their network by any means possible because having homemade projects charge at their stations is a huge liability.

I've been able to fit both 5 tesla batteries and the hyper 9 in the engine bay of my FWD 2010 Ford escape.

The integrated inverter and reduction gearing is definitely a bonus, but like you said can add complications in some scenarios. The Tesla SDU is a more powerful, better motor, but it isn't necessary for more modest projects.
 

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Discussion Starter · #7 ·
I agree with both arguments. I think if i had a viable transmission i probably would go with a hyper9 like setup, easier to mount, range is not a huge factor, but in my current situation i would realistically be spending 4 grand on a transmission just to make the motor work/fit which seems like a poor choice. I think the weight and cost (when considering tranny) probably still favors hyper9 once you consider voltage needs but i think i would rather spend the tranny money on range and power.

I like the calb modules, thanks for the suggestion im not sure how to go about getting them in the us, but it looks like 24 modules would save me about 200 lbs compared to tesla modules and the cost once you include cooling plates seems similar. How are you enclosing them in the tranny tunnel? Would you share your box designs?
 

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Discussion Starter · #10 ·
Those Super cells look great, but its the cooling system that makes me hesitant. I am ok with doing some fabrication, but I am not sure how I would efficiently cool say 32 of those modules.
 

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Many people don't cool them. If you're not aggressively charging (charge overnight vs public fast chargers...note you can throttle back public chargers...the car determines the current), you don't have to. Warming is only needed for cold weather ops.

I don't think any of the batteries in Electric Car Conversions' vehicles are liquid cooled/warmed.
 

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Some counter-points:
Excellent discussions, just as a forum should be.


How are you enclosing them in the tranny tunnel? Would you share your box designs?
Here in Australia, one of the roadworthy requirements for the battery box is that it needs to be able to take a 10G impact and not split open. in a diy build this is theoretical because nobody is asking for an actual crashed vehicle as test data unless your a large volume manufacturer.
My box will be integral to the 3mm aluminium belly pan that mounts between the chassis rails. the pan will be reinforced with aluminium strapping welded to it, giving it more strength and a suitable mounting face for the top cover that will also be made of 3mm aluminium sheet, cut, folded and welded, then bolted down over the battery modules. They will be bolted to the big cooling plate, 2 modules on each side, so 4 modules to each 'brick', with 2 bricks in the transmission tunnel box end to end, then the rest in the engine bay in a big box. There will be a small cavity between the edge of the chassis rail, the bottom of the floor before it goes up to the tunnel and the floor of the belly pan. That gives a protected conduit for V lines, coolant hoses, the rear brake line etc.

I haven't drawn it up more than on napkins etc, I really need to make some time to draw it up on a computer. If anyone wanted to follow my plans, its a free world.
 

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Discussion Starter · #14 ·
Excellent discussions, just as a forum should be.


I haven't drawn it up more than on napkins etc, I really need to make some time to draw it up on a computer. If anyone wanted to follow my plans, its a free world.

Very cool, thanks. I called ev west and i think those lg modules seem like the best bet for me i think they could almost all fot in the engine bau with a few in the fuel tank area it would be a 26 total modules.

Any thought about what to do about climate control/ac? I called a couple aftermarket ac places and they really didnt seem interested in helping. Vintage air pretty much told me they wouldnt sell anything to me of i was planning on doing any thing electric and Restomod said they would sell a system but warranty and support would be void with an electric compressor. Ideally id like to do a real heat pump system like the nissan leaf but sans buying a junked leaf it seems pretty hard to pull this together. Could one just put an electric compressor with the delorean AC unit? It might work for ac but not heath i think
 

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I'm puzzled - doesn't the car have a heater core and a/c evap in the dash already?

Warranty void with an electric compressor? Won't sell? Next time you call, tell them you're dropping a Cummins in and the good ole boyz'll likely give you the 25% coal miner discount.
 

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Discussion Starter · #16 ·
Yea that was the feeling i got. if i told them i was going to run a generator to turn the compressor they would have been cool with that. The car has an evaporator and heater core but the heater could wouldnt work in our case right? i suppose i could pipe the tesla motor coolant through the core but it wouldnt get very warm. I was hoping to make a heat pump like system that could do hot or cold through the evaporator box. i would think an ac shop worth their salt would be able to advise me on it, but this isnat a very popular option.
 

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Just buy an immersion heater for the coolant loop to the heater core. The one in the Bolt EV heats coolant to 130F, so it doesn't need to be raging hot, then runs it through a normal heater core.

Not much heat comes off the inverter/motor when you need it....sitting in the driveway all night, 26F temperature, frosted windshield, and you're stepping out of a warm house.

The factory evap can be run by an electric compressor.

Heat pump is beyond the reach of most diy. That includes many AC shops.
 

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Ceramic heating element is generally the cheapest and simplest way to get cabin heat. If the heater core is accessible, I'd consider going that route.

For AC, just using an electric compressor with the original system would probably be your best bet.

Heat pump and AC shared systems are not so simple I believe, which is why many EVs have only just started to use them.
 

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Just buy an immersion heater for the coolant loop to the heater core. The one in the Bolt EV heats coolant to 130F, so it doesn't need to be raging hot, then runs it through a normal heater core.

Not much heat comes off the inverter/motor when you need it....sitting in the driveway all night, 26F temperature, frosted windshield, and you're stepping out of a warm house.

The factory evap can be run by an electric compressor.

Heat pump is beyond the reach of most diy. That includes many AC shops.
Interesting that 130f is enough for cabin heat, I've always thought that a higher temp is needed with heater cores. I feel like I don't get usable heating until the coolant gauge shows like 170f on my ICE.
 
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