Z3 EV Conversion
- Thread starter Andybpowell
- Start date
Probably 60-70 miles
- Joined
- Dec 8, 2011
- Points
- 145
Bugger me. Did you realise it would be so little when you started the project? I would enjoy overcoming the technical challenges, but would be very disheartened by the range - unless it is 70 track miles and you can trailer it to the track. Then it would be big smile time.
I wish I knew you were doing that, I would have bought your cutout and installed it with a couple of exhaust tips on the other side of my Z, to discourage rev heads from taking me on...just got the laquer to do tomorrow and that's another job off my list (doesn't seem to get shorter)
View attachment 265333
. But now you have ruined it by filling it up with fiberglass and putty, you did a great job of it BTW , but now It,s worthless to me...Following your conversion with interest...
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yes I was aware of the range limitation most production electrics have 50Kwh plus packs completly redesigning, using all available space and swapping to the lexus drivetrain which I believe @Tom Cheesewright is going to use in his next build I believe I could fit in around 44Kwh but the battery pack alone would weigh in excess of 300Kg which would have a detrimental effect on performance, range and handling it's all a big juggling act and as I rarely do more than 12-15 miles in one trip this particular compromise suits me
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Same. I drive my kids to their clubs and do the occasional shop in this car. Rarely more than 15 miles in a day.yes I was aware of the range limitation most production electrics have 50Kw plus packs completly redesigning, using all available space and swapping to the lexus drivetrain which I believe @Tom Cheesewright is going to use in his next build I believe I could fit in around 44Kw but the battery pack alone would weigh in excess of 300Kg which would have a detrimental effect on performance, range and handling it's all a big juggling act and as I rarely do more than 12-15 miles in one trip this particular compromise suits me
With a second pack I'll have about 50 mile range and with fast charging, that's absolutely loads.
Nonetheless, for the next one I'm targeting 36kwh and enough range to get from my house in Manchester to my folks in the Midlands. Or across the Pennines to see fellow EV nerds. I think that's about as much as you can put in a Z3 without ruining the dynamics, or making it unsafe, based on current battery tech.
So this is my front battery pack going back together on the surface it doesn't look much differant but it's been quite a bit of work
on the original modules I had in there I'd drilled out the mounting holes from 6mm to 8mm as it seemed a bit small for the way I was mounting the pack but it was a lot of work and I didn't want to do it this time with the new modules so I had to tap the bottom cooling plate and fit M6 inserts then cut all of the new M6 studding then make up all new spacers all before starting to reassemble the pack, applying the heatsink compound, fitting the modules connecting the BMS units and adapter boards then doing the same thing for the upper 3 modules
And here it is being tested all I have to do now is make some new HV cables and completly re-do all of the HV contactors and connections, add the OEM BMW HV plug and socket to go to the inverter, move the low voltage power and canbus connector refit the battery then I can start on the rear battery pack connections
and now you can see why it takes so long
on the original modules I had in there I'd drilled out the mounting holes from 6mm to 8mm as it seemed a bit small for the way I was mounting the pack but it was a lot of work and I didn't want to do it this time with the new modules so I had to tap the bottom cooling plate and fit M6 inserts then cut all of the new M6 studding then make up all new spacers all before starting to reassemble the pack, applying the heatsink compound, fitting the modules connecting the BMS units and adapter boards then doing the same thing for the upper 3 modules
And here it is being tested all I have to do now is make some new HV cables and completly re-do all of the HV contactors and connections, add the OEM BMW HV plug and socket to go to the inverter, move the low voltage power and canbus connector refit the battery then I can start on the rear battery pack connections
and now you can see why it takes so long
Have you got the 1.5 or 2kwh modules in your pack ?
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1.5 in the first car. 2kwh going in the second one.
It should only take me one more day to finish getting my 20Kwh pack finished then I can start some testing just need one day of good weather to get under the car to run the cables cant wait to dome some range and performance testing done
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So that one good day I needed turned into a weekIt should only take me one more day to finish getting my 20Kw pack finished then I can start some testing just need one day of good weather to get under the car to run the cables cant wait to dome some range and performance testing done
The modifications to the front battery box making new cables, re-routing many of the cables, making blanking plates and connecting the inverter via an oem bmw connector took 2 days
Making new cables for the rear batteries, sorting out the bms wiring and actually low and high voltage cables into the boot took another 2 days
It then took me 2 days yes 2 days to to run the HV cables from the front battery box to the rear I did also change the gear oil but that only took about 30 min
Then another day programming the BMS, VCU and my cockpit display to make it all work
So a week later and the Z is back on the road with a 20kwh battery instead of 9kwh I'm still tweaking the settings so it's not perfect but bloody hell it goes well
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So my Z3 is 95% finished just some tidying and retrimming to do, but I do this stuff for fun the issue lies in working space I don't have enough for a new project so would have to sell my Z3 so the real question is how difficult would it be to sell a converted car what specific problems would arise
I'm not sure that's what I want to do just yet but I'm considering it and I wouldn't even know what value to put on it the amount of man hours is obscene I'm retired and I've literally spent the last year doing this conversion but it's not about profit if I got somewhere over what it's cost in vehicle purchase and parts to fund the next project I'd be happy the car is mot'd and registered electric so theoretically it should be no differant to selling any other modified car
So any thoughts ?
I'm not sure that's what I want to do just yet but I'm considering it and I wouldn't even know what value to put on it the amount of man hours is obscene I'm retired and I've literally spent the last year doing this conversion but it's not about profit if I got somewhere over what it's cost in vehicle purchase and parts to fund the next project I'd be happy the car is mot'd and registered electric so theoretically it should be no differant to selling any other modified car
So any thoughts ?
Your market is likely to be very limited. There must be specialist/enthusiasts out there somewhere though. Maybe you could contact Classic Car weekly or like and see if they were interested in doing an article? Good luck with selling! 
Not sure I'm actually going to sell it yet but I've got my eye on an audi tt thats calling to me and just don't have the space oh and it would be another ev conversionYour market is likely to be very limited. There must be specialist/enthusiasts out there somewhere though. Maybe you could contact Classic Car weekly or like and see if they were interested in doing an article? Good luck with selling!
What sort of voltages are present on the Hv side and what is the output voltage from the inverter ?
330v for both
I'm still working on the EV conversion as there are lots of little jobs to do
the nextion display inside which gives me information on the battery, motor and charging system and allows me to make certain changes to the systems has been finalised and I'm happy with the information it provides just got to change the scaling on the temperatures also I actually got around to painting it as it's been in primer for 4 months
also did a short video of it (very boring)
View: https://youtu.be/28Y4Agc4-08
also did some tidying up under the bonnet
and started re-trimming the boot just waiting for some more carpet as I ran out
I've still got to clean up the edges and re-trim the drivers side but I ran out of carpet
the nextion display inside which gives me information on the battery, motor and charging system and allows me to make certain changes to the systems has been finalised and I'm happy with the information it provides just got to change the scaling on the temperatures also I actually got around to painting it as it's been in primer for 4 months
also did a short video of it (very boring)
also did some tidying up under the bonnet
and started re-trimming the boot just waiting for some more carpet as I ran out
I've still got to clean up the edges and re-trim the drivers side but I ran out of carpet
Just when you thought it was all over it seems I'm still playing
Certain things about the instrument cluster have really been bugging me and it's not possible to control the way I want to use the dash to display data from my ev due to limitations put in by BMW so I've decided strip the instrument cluster and rebuild and control it the way I want
View: https://youtu.be/-FllcwRhMfA
Certain things about the instrument cluster have really been bugging me and it's not possible to control the way I want to use the dash to display data from my ev due to limitations put in by BMW so I've decided strip the instrument cluster and rebuild and control it the way I want
I like your attitude towards this problem, I hope you can get it the way you want.
So just for the record I did actually finish this project minus the cluster rebuild which is almost a project in it's own right and I might actually start another thread for just that so this is the final part the finalised boot retrim
And now I'm going to rip it all out and start again
Having done 500 electric miles in the car I've never been quite happy with keeping the standard gearbox it has 120 odd thousand miles on it and had no oil in it when I checked it shortly after buying the car, the electric motor tops out at just over 10,000 rpm at which point the gearbox is screaming also I wasn't 100% happy with the coupling that I made I could fix both of these things relativly easily but I like a challenge so I'm replacing it all with a lexus is300h hybrid transmission, this has 2 electric motors within the transmission itself and is rated I believe at 105kw and 300Nm of torque the advantages of using this over my current setup is a slight weight reduction about 10kg and the weight will be moved further back towards the center of the car no coupling between motor and gearbox as it's all one unit and more room up front so I can re fit the original 12v battery but in the front, I had to fit a much smaller motorbike battery in the boot after I fitted the rear HV battery pack due to lack of space and the final and most important reason is because I'm just playing and I want to
I've already ordered the new transmission, inverter, Zombieverter controller and a lexus propshaft to cut n shut and I may or may not have spent a big chunk of money on another battery told the wife and she said "oh good then I can tell you what I just spent on egyptian cotton for the bed"
And now I'm going to rip it all out and start again
Having done 500 electric miles in the car I've never been quite happy with keeping the standard gearbox it has 120 odd thousand miles on it and had no oil in it when I checked it shortly after buying the car, the electric motor tops out at just over 10,000 rpm at which point the gearbox is screaming also I wasn't 100% happy with the coupling that I made I could fix both of these things relativly easily but I like a challenge so I'm replacing it all with a lexus is300h hybrid transmission, this has 2 electric motors within the transmission itself and is rated I believe at 105kw and 300Nm of torque the advantages of using this over my current setup is a slight weight reduction about 10kg and the weight will be moved further back towards the center of the car no coupling between motor and gearbox as it's all one unit and more room up front so I can re fit the original 12v battery but in the front, I had to fit a much smaller motorbike battery in the boot after I fitted the rear HV battery pack due to lack of space and the final and most important reason is because I'm just playing and I want to
I've already ordered the new transmission, inverter, Zombieverter controller and a lexus propshaft to cut n shut and I may or may not have spent a big chunk of money on another battery told the wife and she said "oh good then I can tell you what I just spent on egyptian cotton for the bed"