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Discussion Starter · #1 ·
Hi all,
Looking into converting my 71 lotus to ev. This has a renault 16 engine and box inside, so not much fun.
Will be using 5 tesla batteries or 10 lg batteries which will fit. Looks like I will need to use a hyper 9 to audi transaxle with mounts off the gearbox for bottom wishbone mounts. I originally wanted to use a leaf motor, but that's a high voltage motor and I don't think I can get all those batteries in or upset the handling. Question is am I correct about the leaf.
Thks
 

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The LG Chem 16S modules (intended for a Chrysler Pacifica Hybrid) run at 60 V (nominal), so ten of them would run at 600 volts; you probably meant a 5S2P of ten modules, for 300 volts. Or did you mean a different LG module? The Leaf has a nominal battery voltage of 360 V (like most recent EVs), and the controller and motor can run on somewhat lower voltage. Why do you think you can't get in enough battery modules for the Leaf, if one of your proposed battery configurations runs at a suitable voltage?

To use a salvaged EV motor at the intended voltage (about 360 V nominal for almost all recent EVs) using modules from a recent EV, you need a complete set (the number that came in the original pack). A complete set of Tesla modules (from any model) will be too large, but a complete set from a plug-in hybrid (such as the Chrysler Pacifica Hybrid or Chevrolet Volt) will fit.
 

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While the mass of the battery is certainly an issue, space for the battery is another substantial issue. The backbone frame design of the Europa is terrible for fitting in battery modules: if you place them over the frame in the engine area they're too high for good handling, and if you put them between the frame rails behind the axle the mass is too far back (and you can't use the original transaxle or a similar replacement).
 

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Discussion Starter · #4 ·
Hi Brian,
Lg 4p3s are 2.6khw 11volts each. So 10 is 26khw and 110volts. Zero ev in England use this on there maxda mx5 with a hyper 9, but is not cheap.
My lotus has 2 x 25 liter tanks each side, so space there and on top of the motor. Four would go under the bonnet. I can drill four holes in the fiberglass and pick up the chassis and fix mounts for a battery box mount.
Leaf would be cheaper option but higher voltage.
Fabrication work not a problem for me, spent years working on hillclimb specials.
This is my much modified ginetta g15
Motor vehicle Vehicle Hood Car Automotive design
 

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Lg 4p3s are 2.6khw 11volts each. So 10 is 26khw and 110volts. Zero ev in England use this on there maxda mx5 with a hyper 9, but is not cheap.
Ah, that makes more sense. There are many LG Chem modules, both in production EVs and offered separately, so it's necessary to be more specific.
Yes, modules which are only 3S but 6 L in volume and 12 kg in mass (typical for this format) implies 32 of them for a 360 V nominal pack, of 192 L and 385 kg total (and usually 64 to 80 kWh)... too much for the Europa. Ten makes a reasonable pack, but limits you to low-voltage motors; the HyPer 9 is built for small industrial vehicles (although sold by NetGain for EV conversions).

Those 3S4P modules are in the VDA 355 format (355 x 151 x 108 mm). There are other modules in that size, all of about the same energy capacity and typically containing 12 pouch cells, and some have different configurations. Electric GT's OX Drive Energy line includes both 4S3P and 6S2P modules, so 360 V nominal pack voltage could be reached in 24 or 16 modules. Yes, they're expensive (16 modules from Electric GT would cost $11,120 USD, for 35.2 kWh), but any new battery is. At least some variations of the VW eGolf use this size format, in 4S3P, and the Audi e-tron may use the same size, in 3S4P.
 

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My lotus has 2 x 25 liter tanks each side, so space there and on top of the motor. Four would go under the bonnet. I can drill four holes in the fiberglass and pick up the chassis and fix mounts for a battery box mount.
The fuel tank spaces are really awkward, extending in a vertical box on each side, between the rear wheels and the passenger compartment, outboard of the frame and suspension. The top portion is logically an extension of the engine space, but the bottom part is really only reachable through the access holes in the bottom of the fiberglass body. The lower parts might be good for pumps, valves, or electronics such as the charger.

If the target under-bonnet space is ahead of the axle, I would be concerned about mass distribution there. The shelf behind the front axle, over the footbox, doesn't seem large enough for modules, although it could be a good electronics and 12 V battery location.
 

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2007 Proton Jumbuck GLi running Nissan eNV200 Gear
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Tesla modules are the way to go for power density. The integrated cooling loop is also a big factor in why people use them.
True on that, however after much looking into it, really depends on the application.

I'm planning to drive mine daily, in Australia, and as I type this, it is 35 degrees C, so this is the kind of day I'll be running.

But, on that note, I'm not going to be causing that heavy of a discharge, or that heavy of a charge, so going with the Air Con loop on the Nissan eNV200 setup is fine for me and what I'm doing.

But 100%, when I build the next rig, whatever form that takes, I'll probably be demanding a lot out of the batteries, and thus I'll need a cooling loop with some form of direct to cell cooling, rather than passive overflow cooling.

Being a Lotus, I think that the temptation to drive it hard will be overwhelming (for me at least) and I'd want to give it the Jandal every time I got the change haha
 

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Fabulous project !
Where in the UK are you ? (I'm in Dorset)

I agree with others - higher voltage motors give slightly more efficiency and most OEM EV’s tend to use 400 volts. Power = volts x amps, so 100kW = 400 volts x 250 amps.
But for more amenable battery weights and placement the lower 125 volts x 800 amps of a Hyper9 works well (as long as the modules can deliver the amps and you have thick cables) . Then you get an overall weight that Colin Chapman would approve of :).

If I were doing another lightweight lotus, caterham (or Formula Ford :cool: ), I'd probably use some iPace, LG or Calb packs from Zero EV. These have similar costs and weight per kWh, as Tesla modules, but in smaller more useful units > Modules - Zero EV . Only advantage of Tesla Modules I liked is simpBMS only works with them along with other ex OEM packs (tesla, GM, Mitsubishi etc.). Instead you'll probably need to wire up the (superior) Orion BMS, or similar.
 

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If I were doing another lightweight lotus, caterham (or Formula Ford :cool: ), I'd probably use some iPace, LG or Calb packs from Zero EV. These have similar costs and weight per kWh, as Tesla modules, but in smaller more useful units > Modules - Zero EV .
Those are the VDA 355 (or "shoebox") format which I mentioned earlier. I forgot to mention the I-Pace; as discussed in another thread (and another thread) the LG modules listed by Zero EV were previously identified as "X590" (Jaguar's internal project ID for the I-Pace).
 

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Discussion Starter · #13 ·
Hi 4foxtrot,
Yep, I did look at lg batteries from zero ev as they use in there mx5 conversion. 10 lg batteries wouldn't be a big problem to space around motor and under bonnet. I think I have more space than you did.😀 I'm usec to squeezing things in. My ginetta g15 was tight with a front wheel drive volvo turbo in the back of the space frame. With the lg batteries what would the difference be using 12 as apposed to 10. Once you get the voltage correct for motor is max power made and the extra battery just gives you range. I should know this as a industrial electrical engineer. Back to the coupling, did you get from industrial suppliers and get machined to fit motor or did it come 1.125 imperial. If you had a part number or better picture that would help. Thanks Paul.
Oh and I live in Kent on the end of biggin Hill Airport. Love the sound of the spitfires taking off and landing all day long taking people on joy rides.
 

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Hi Paul
Like G15's too.
Adding extra batteries in series increases both voltage and range, but limited by the controller Hyper9 AX1 upper voltage level is around 130 volts. But as I find, voltage varies enormously depending on SOC, Regen and amps pulled .. so if your pack is near the max voltage the controller can handle, regen would not be available (and if set up badly, you could over-volt the packs which could be expensive !!).

I bought a standard motor coupler (on ebay from USA or an ev store, ev west / ecc etc $50 iirc ) as it was already tolerance correctly for motor shafts and keys. I then had a machine shop make the matching Ali part. I cadded + cnc'd up the 'bellhousing replacement' optimised for weight and strength.

couplers standard parts in USA

Nice part of the world, Biggin Hill
cheers
Mark
 

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With the lg batteries what would the difference be using 12 as apposed to 10. Once you get the voltage correct for motor is max power made and the extra battery just gives you range.
But there is no "correct" voltage for the motor. More pack voltage means more voltage available to the motor, which means motor output sustained to a higher speed... until you violate the upper voltage limit of the controller (you're unlikely to have an issue with excessive motor voltage).

Sustaining high torque to higher motor speed can mean not just more power available at high road speed, but also the ability to use a greater gear reduction ratio (called "shorter gearing"), and thus more available torque to the wheels at all speeds. If you can't deliver enough power from the battery to use this it's pointless, if you don't have shorter gearing available that's not an advantage, if you have a multi-speed transmission that's not much of an advantage, and if you can already spin the motor as fast as it mechanically allowed the electromagnetic ability to run faster doesn't help. ;)

The I-Pace/X590 VDA 355-sized modules (from Zero EV or others) are 3S4P, so ten or twelve of them is 30S or 36S. At 11 V nominal and 12.6 V max, that's
  • 10 modules @ 3S each: 110 V nominal, 126 V max (26 kWh)
  • 12 modules @ 3S each: 132 V nominal, 151 V max (31 kWh)
Assuming that the plan is still a HyPer 9 motor, with one of the AC-X1 controllers sold for them, you would presumably need the higher-voltage version to use either of these battery configurations, assuming that what NetGain is calling an AC-X1 is the version for nominal voltage up to 100 V. NetGain publishes performance data for the regular (not "HV" or high-voltage) version of the HyPer 9 up to 132 V, so the 10-module configuration is not capable of driving this motor to its highest power capability.

Also, if there is a real spec somewhere for current or power output ratings for these modules, you may find that you need more than ten modules to handle what the motor can use; more modules means less current for the same power from the pack.
 

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Discussion Starter · #17 ·
Hi Paul
Like G15's too.
Adding extra batteries in series increases both voltage and range, but limited by the controller Hyper9 AX1 upper voltage level is around 130 volts. But as I find, voltage varies enormously depending on SOC, Regen and amps pulled .. so if your pack is near the max voltage the controller can handle, regen would not be available (and if set up badly, you could over-volt the packs which could be expensive !!).

I bought a standard motor coupler (on ebay from USA or an ev store, ev west / ecc etc $50 iirc ) as it was already tolerance correctly for motor shafts and keys. I then had a machine shop make the matching Ali part. I cadded + cnc'd up the 'bellhousing replacement' optimised for weight and strength.

couplers standard parts in USA

Nice part of the world, Biggin Hill
cheers
Mark
Hi 4foxtrot,
Yep, I did look at lg batteries from zero ev as they use in there mx5 conversion. 10 lg batteries wouldn't be a big problem to space around motor and under bonnet. I think I have more space than you did.😀 I'm usec to squeezing things in. My ginetta g15 was tight with a front wheel drive volvo turbo in the back of the space frame. With the lg batteries what would the difference be using 12 as apposed to 10. Once you get the voltage correct for motor is max power made and the extra battery just gives you range. I should know this as a industrial electrical engineer. Back to the coupling, did you get from industrial suppliers and get machined to fit motor or did it come 1.125 imperial. If you had a part number or better picture that would help. Thanks Paul.
Oh and I live in Kent on the end of biggin Hill Airport. Love the sound of the spitfires taking off and landing all day long taking people on joy rides.
 

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Discussion Starter · #18 ·
Hi 4foxtrot,
Now that you've been on the road for sometime, would you preferred to have a clutch or not. In two minds. Or is it OK to change on the move on the way up the box.
I'm going to use a 5 speed audi a4 box and modify the bottom link two a twin link system so I can use cv's. And beef up the chassis.
Thks paul
 

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Hi 4foxtrot,
Now that you've been on the road for sometime, would you preferred to have a clutch or not. In two minds. Or is it OK to change on the move on the way up the box.
I'm going to use a 5 speed audi a4 box and modify the bottom link two a twin link system so I can use cv's. And beef up the chassis.
Thks paul
TBH 50:50 to keep the clutch- it would be quicker to change gear than the software (regen off) solution, but adds weight and more to go wrong -- I also have BIG feet so 2 pedals are very very nice :)
 

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Hi all,
Looking into converting my 71 lotus to ev. This has a renault 16 engine and box inside, so not much fun.
Will be using 5 tesla batteries or 10 lg batteries which will fit. Looks like I will need to use a hyper 9 to audi transaxle with mounts off the gearbox for bottom wishbone mounts. I originally wanted to use a leaf motor, but that's a high voltage motor and I don't think I can get all those batteries in or upset the handling. Question is am I correct about the leaf.
Thks
 
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