[alexandrept21]

Hello,

I am working on a Fiat 600 from 1969, and i am thinking of converting it to eletric. I already choose all the components of the eletric system but i am not sure that it will run without problems so i am here to see if any of you notice something missing.

The eletric system consists on:

• HPEVS motor AC35 96V 650A
• Curtis controller 1238E-7621 (72/96V 650A) with cooling plate
• Curtis Foot Pedal
• CALB CA180FI or CA100FI batteries (still figuring out the battery boxes)
• Cooling liquid pump (and a radiator?) for the controller and batteries
• Elcon PFC2500 battery charger
• Mennekes plug and connector
• Orion BMS 2
• Gigavac GV240 contactor for starting the car
• Gigavac HBD41 manual switch for maintenance
• TBS battery monitor expert modular 12V (with shunt)
• Curtis DC/DC converter 1400 72/96V

What do you think? Should i change something or this system would work fine? I will take any help i can get!

Cheers!

 

[schelle63]

Hi Alexandre,
with 63hp you will need a new set of tyres every 4 weeks, besides of having a lot of fun. (My personal opinion: for a daily driver, half the power is sufficient.) It seems that You want to keep the transmission, which I consider wasting weight and space - both is rare and precious in a 600 FIAT. You may consider a (second-hand?) motor/diff-unit, might be unbeatably compact.
I cannot see what range You are planning, or if it is going to remain a 4-seater, but keep an eye on the car's total weight and its front/rear-distribution. Otherwise the beast will be hard to drive.
I wish You good success, and keep us informed about the progress, with many pictures!
Markus

 

[alexandrept21]

Hi Alexandre,
with 63hp you will need a new set of tyres every 4 weeks, besides of having a lot of fun. (My personal opinion: for a daily driver, half the power is sufficient.) It seems that You want to keep the transmission, which I consider wasting weight and space - both is rare and precious in a 600 FIAT. You may consider a (second-hand?) motor/diff-unit, might be unbeatably compact.
I cannot see what range You are planning, or if it is going to remain a 4-seater, but keep an eye on the car's total weight and its front/rear-distribution. Otherwise the beast will be hard to drive.
I wish You good success, and keep us informed about the progress, with many pictures!
Markus

Maybe reducing the system to 48V would work. According to the manufacturer of the motor, it would get a maximum of 27 HP that way, which is closer to the original. I would need to select a different controller but everything else could stay the same.
About the transmission, in my country is really dificult to legalize these kinds of projects so i am trying to not mess with anything that isnt really necessary and it would make the project a bit more expensive...
Its suppose to be a city car so maybe a 75-100km range would be good. A bunch of CALB batteries in the engine bay and some in the frunk and i think it would be good, at least i hope!
Thank you for your reply!

 

[schelle63]

I just found this:

Seems to be a school project.
Where do you come from? It might be an advantage (legally) to use certified parts from an OEM, such as a complete drive unit.
If reduced power does not come with a weight benefit, you should stay with the 63hp. Make the voltage as high as you can, this keeps current (Amperes) low and you save cable diameter (= weight)
100km appears reasonable, my Mini (660kg) does this with a 90kg battery pack made of 18650-cells.

Markus

 

[brian_]

I wouldn't get excited about 63 HP being too much, since that's only a peak value (can't be sustained without overheating) at the ideal speed (2900 RPM). To get anything close to that a multi-speed transmission would be needed; if you take the usual production EV approach of a single reduction ratio, at anything other than the ideal road speed it would have less power available - and that's probably okay. I assume that in picking this specific motor you have looked at the performance charts from HPEVS.

For the battery 96 volts (nominal) at 3.2 V/cell implies 30 cells in series, so
CA100FI pack would total 99 kg and 62 litres for 10 kWh, and
CA180FI pack would total 168 kg and 101 litres for 18 kWh,
... plus interconnections, structure, and housing in each case. If the volume is hard to visualize, that's a row
216 mm x 142 mm x 2 m long (CA100 cells), or
279 mm x 180 mm x 2 m long (CA180 cells).

Those are actually relatively small packs, but this is a very small car... it will be interesting to see where they go. The stock fuel tank is in front, so a small pack could go there. With a stock transmission and AC-35 there would be little room left in the rear - perhaps a row of cells to each side of the motor or one across above the motor - so the rear seat becomes the next target.

 

[alexandrept21]

I just found this:

Seems to be a school project.
Where do you come from? It might be an advantage (legally) to use certified parts from an OEM, such as a complete drive unit.
If reduced power does not come with a weight benefit, you should stay with the 63hp. Make the voltage as high as you can, this keeps current (Amperes) low and you save cable diameter (= weight)
100km appears reasonable, my Mini (660kg) does this with a 90kg battery pack made of 18650-cells.

Markus

Yeah those videos are nice, i already had seen them.
I'm from Portugal. I understand what you are saying but i feel like the less i change in the car the easier it will be to legalize, at least that is what i got from the research i did on this subject here in my country. If i change other things it needs to go to safety tests and it becomes very expensive and time consuming.
So is it okay to only have batteries in series? I saw some EV conversions and they use blocks of 4 paralel and 3 series and then they have a bunch of those blocks in series...
Can you send me the list of components you got to convert your mini? Its a similar car to mine, it would help i guess.

 

[alexandrept21]

I wouldn't get excited about 63 HP being too much, since that's only a peak value (can't be sustained without overheating) at the ideal speed (2900 RPM). To get anything close to that a multi-speed transmission would be needed; if you take the usual production EV approach of a single reduction ratio, at anything other than the ideal road speed it would have less power available - and that's probably okay. I assume that in picking this specific motor you have looked at the performance charts from HPEVS.

For the battery 96 volts (nominal) at 3.2 V/cell implies 30 cells in series, so
CA100FI pack would total 99 kg and 62 litres for 10 kWh, and
CA180FI pack would total 168 kg and 101 litres for 18 kWh,
... plus interconnections, structure, and housing in each case. If the volume is hard to visualize, that's a row
216 mm x 142 mm x 2 m long (CA100 cells), or
279 mm x 180 mm x 2 m long (CA180 cells).

Those are actually relatively small packs, but this is a very small car... it will be interesting to see where they go. The stock fuel tank is in front, so a small pack could go there. With a stock transmission and AC-35 there would be little room left in the rear - perhaps a row of cells to each side of the motor or one across above the motor - so the rear seat becomes the next target.

Hey,

Yes, i saw the performance charts from hpevs and that was why i choose the AC-35 with a 96V system, but come to think of it and maybe its a bit overkill, maybe a 72V system would be better just to have a bit more power than the original. With that it gives 48HP peak, what do you think?
Thank you for your help. I was aiming for a 15kWh but maybe just 10kWh would be sufficient. I was thinking of putting a box over the motor and a box in the frunk. If that isnt sufficient then maybe putting some in the back seats but i am trying to maintain those seats...
Here is the video that i am basing my project on:

If i get anything close to that i would be happy!

Im also making the project in CAD to see if the components fit before i buy them (and also because its part of my thesis), here is a pic of the back:

When i add the motor and the battery packs i will update you!

Cheers

 

[brian_]

Here is the video that i am basing my project on:
...

This isn't a bad walkaround - certainly much better than some I've seen - but it's annoying to see only the outsides of the battery boxes. I assume that their target is just potential customers for their kit, rather than anyone really doing it themselves. For those not using Tesla battery modules, this doesn't matter.

Comparing the weight and power of an engine to an electric motor is nonsense, because the motor can't do anything without a huge battery - only complete system weights (engine plus fuel, cooling, etc. versus motor plus battery, controller, charger, cooling, etc) can be reasonably compared.

They are not getting much advantage out of the transmission, only using two gear ratios. It's mostly a conversion convenience, allowing them to use an off-the-shelf adapter for the motor to the transmission and single motor mount, without worrying about anything else mechanically or structurally.

The rear pack is across the car above the motor. This is a really high location for a substantial mass, but is a viable possibility for some of the battery modules, for most module types (including a row of CALB prismatic cells). Some conversions of rear-engine cars have placed modules along each side of the motor, but in this case either there is not enough space, or vehicle structure is in the way, or they need the room for the electronic components (although those seem to be entirely above the motor in this case), or they just wanted to use Tesla modules which are too long and wide to fit there; a row of CALB cells or a small rectangular module (one of the LG Chem or CALB units) might fit.

And of course this is a Fiat 500 but the current project is a 600, which is a bit bigger.

 

[brian_]

I was thinking of putting a box over the motor and a box in the frunk. If that isnt sufficient then maybe putting some in the back seats but i am trying to maintain those seats...

Im also making the project in CAD to see if the components fit before i buy them (and also because its part of my thesis), here is a pic of the back:
View attachment 120273

When i add the motor and the battery packs i will update you!

The planning is looking good, and I'm looking forward to those updates.

It does look like a module or some cells on each side of the motor (assuming the motor mounted to the original transaxle) might be possible. That would be lower (better for stability and handling) than over the motor, but it would also be slightly further rearward (which isn't desirable).

I had not noticed that this project is also an academic exercise. It would be good to work out the centre of mass location, both front to back (determining axle load distribution) and vertically (affecting stability, responsiveness, and load transfer on acceleration and braking) either in the CAD tool or separately, for the alternative configurations.

 

[brian_]

So is it okay to only have batteries in series? I saw some EV conversions and they use blocks of 4 paralel and 3 series and then they have a bunch of those blocks in series...

Cells in parallel at anything other than the lowest level of the configuration are a problem for balancing and management.

What every production EV battery configuration does is connect enough cells in parallel groups to get the desired capacity (anything from only one 43 Ah cell in the Chrysler Pacifica Hybrid, to 2 to 4 cells at 40 Ah to 60 Ah in most EVs, to dozens of little cylindrical cells in Teslas), then connect enough of those groups in series to get to the desired operating voltage (most commonly 96 groups for 360 volts nominal). The series is broken up into modules of a manageable size, which doesn't matter electrically. In this system, the battery management system needs only one tap into the battery per group to monitor voltage at the cell level and to balance the charge level of all groups; there is only one set (on positive and negative) of disconnect relays needed and only one charging current to manage.

Because modules don't come in the sizes and configurations specifically suited to all conversions, many builders assemble other configurations. The most common is to build a typical (parallel at lowest level, then series those groups) pack of the desired voltage from available modules, then build two or more of those packs or "strings" and connect the strings in parallel to get enough power and energy capacity. This requires a complete set of battery management hardware for each string including possibly shutting off charging separately. Examples include the people who have used two complete sets of Chevrolet Volt modules, as two parallel strings.

With individual cells such as the CALB prismatics, the only sensible thing to do is the same as production EVs - parallel first. With the cell capacities, total capacity, and target voltage originally proposed for this project, the only reasonable configuration would be all 30 cells in series. Connecting the 100 Ah cells in parallel pairs and 22 of those pairs in series would result in a 200 Ah 70 V (14 kWh) pack.

 

[alexandrept21]

This isn't a bad walkaround - certainly much better than some I've seen - but it's annoying to see only the outsides of the battery boxes. I assume that their target is just potential customers for their kit, rather than anyone really doing it themselves. For those not using Tesla battery modules, this doesn't matter.

Comparing the weight and power of an engine to an electric motor is nonsense, because the motor can't do anything without a huge battery - only complete system weights (engine plus fuel, cooling, etc. versus motor plus battery, controller, charger, cooling, etc) can be reasonably compared.

They are not getting much advantage out of the transmission, only using two gear ratios. It's mostly a conversion convenience, allowing them to use an off-the-shelf adapter for the motor to the transmission and single motor mount, without worrying about anything else mechanically or structurally.

The rear pack is across the car above the motor. This is a really high location for a substantial mass, but is a viable possibility for some of the battery modules, for most module types (including a row of CALB prismatic cells). Some conversions of rear-engine cars have placed modules along each side of the motor, but in this case either there is not enough space, or vehicle structure is in the way, or they need the room for the electronic components (although those seem to be entirely above the motor in this case), or they just wanted to use Tesla modules which are too long and wide to fit there; a row of CALB cells or a small rectangular module (one of the LG Chem or CALB units) might fit.

And of course this is a Fiat 500 but the current project is a 600, which is a bit bigger.

Yeah, they are just trying to sell the conversion kit without explaining every detail... But its a good layout for the components in the conversion i think.

Yes and in my project, i already removed all the engine components and i am going to wheigh in all of it so that when i choose the eletric system and the batteries and all that, the wheight difference wont be a lot (at leats in the back, if it gets a lot heavier in the back i will put some batteries in the front).

The biggest advantage is that i dont have to buy a automatic transmission, making the conversion a bit cheaper.

I am still considering the Tesla Model S batteries, i think in this layout they are probably the best fit. I only have to put 2 tesla batteries in the back above the motor and 1 in the front, giving it a 72V system and about 15kWh. When i design the batteries boxes and have all the important electric components in the CAD desing i will update you to see what you think of it and the components i choose.

 

[alexandrept21]

Cells in parallel at anything other than the lowest level of the configuration are a problem for balancing and management.

What every production EV battery configuration does is connect enough cells in parallel groups to get the desired capacity (anything from only one 43 Ah cell in the Chrysler Pacifica Hybrid, to 2 to 4 cells at 40 Ah to 60 Ah in most EVs, to dozens of little cylindrical cells in Teslas), then connect enough of those groups in series to get to the desired operating voltage (most commonly 96 groups for 360 volts nominal). The series is broken up into modules of a manageable size, which doesn't matter electrically. In this system, the battery management system needs only one tap into the battery per group to monitor voltage at the cell level and to balance the charge level of all groups; there is only one set (on positive and negative) of disconnect relays needed and only one charging current to manage.

Because modules don't come in the sizes and configurations specifically suited to all conversions, many builders assemble other configurations. The most common is to build a typical (parallel at lowest level, then series those groups) pack of the desired voltage from available modules, then build two or more of those packs or "strings" and connect the strings in parallel to get enough power and energy capacity. This requires a complete set of battery management hardware for each string including possibly shutting off charging separately. Examples include the people who have used two complete sets of Chevrolet Volt modules, as two parallel strings.

With individual cells such as the CALB prismatics, the only sensible thing to do is the same as production EVs - parallel first. With the cell capacities, total capacity, and target voltage originally proposed for this project, the only reasonable configuration would be all 30 cells in series. Connecting the 100 Ah cells in parallel pairs and 22 of those pairs in series would result in a 200 Ah 70 V (14 kWh) pack.

And what about with 3 tesla model s batteries in series? i would only need a orion 2 BMS to manage the batteries and it would work fine right? Do i still need the disconnect relays?

 

[brian_]

The biggest advantage is that i dont have to buy a automatic transmission, making the conversion a bit cheaper.

I've apparently missed something here... why would any conversion require you to buy an automatic transmission? Automatic transmissions are a terrible combination with electric motors.

 

[brian_]

I am still considering the Tesla Model S batteries...

While some retailers refer to these as "batteries", and in a sense they are (because they are sets of cells), normal practice in the EV world is to call them "modules". "Battery" is reserved for the complete system of cells (usually arranged in modules) and their housing.

And what about with 3 tesla model s batteries in series? i would only need a orion 2 BMS to manage the batteries and it would work fine right? Do i still need the disconnect relays?

Each Tesla Model S (or X) module is 6 groups of cells, with the groups in series. Three modules would be 18 cell groups in series, so the BMS needs 18 input points for cell group positive taps (plus the pack negative). It doesn't matter whether they are all in one module or are 18 separate modules or anything in-between, as long as the inputs of the BMS can be wired to the cell groups (Orion calls these input connections "cell taps"). Some modules have a BMS slave unit built into them, so only one communications connector is exposed; the Tesla Model S/X modules have slaves like this, but when using the Orion BMS you remove and discard those slaves and use the wiring that the slave was using with the Orion instead.
Using the Orion BMS with Tesla Battery Modules
Orion BMS 2 Wiring & Installation Manual

The Tesla modules do not include disconnect relays, so you need those, but just one set regardless of the number of modules in series.

 

[alexandrept21]

I've apparently missed something here... why would any conversion require you to buy an automatic transmission? Automatic transmissions are a terrible combination with electric motors.

You said this "They are not getting much advantage out of the transmission, only using two gear ratios. It's mostly a conversion convenience, allowing them to use an off-the-shelf adapter for the motor to the transmission and single motor mount, without worrying about anything else mechanically or structurally. ", so what would be the other option?

 

[alexandrept21]

While some retailers refer to these as "batteries", and in a sense they are (because they are sets of cells), normal practice in the EV world is to call them "modules". "Battery" is reserved for the complete system of cells (usually arranged in modules) and their housing.


Each Tesla Model S (or X) module is 6 groups of cells, with the groups in series. Three modules would be 18 cell groups in series, so the BMS needs 18 input points for cell group positive taps (plus the pack negative). It doesn't matter whether they are all in one module or are 18 separate modules or anything in-between, as long as the inputs of the BMS can be wired to the cell groups (Orion calls these input connections "cell taps"). Some modules have a BMS slave unit built into them, so only one communications connector is exposed; the Tesla Model S/X modules have slaves like this, but when using the Orion BMS you remove and discard those slaves and use the wiring that the slave was using with the Orion instead.
Using the Orion BMS with Tesla Battery Modules
Orion BMS 2 Wiring & Installation Manual

The Tesla modules do not include disconnect relays, so you need those, but just one set regardless of the number of modules in series.

I found a company that already sells the module with a cell tap that works with the Orion BMS. its Stealth ev, i think i will use some components from there. and they have the 3D designs of a lot of tings which is great!

 

[brian_]

You said this "They are not getting much advantage out of the transmission, only using two gear ratios. It's mostly a conversion convenience, allowing them to use an off-the-shelf adapter for the motor to the transmission and single motor mount, without worrying about anything else mechanically or structurally. ", so what would be the other option?

A single-ratio gearbox, like almost every production EV uses. Not manually shifted, and not automatically shifted... not shifted at all.

The usual way to do this in a conversion is to use a complete drive unit (motor and transaxle) from a production EV. None are arranged the same way as the Fiat (motor in the rear with the shaft longitudinal) so the fit isn't obvious, but a Porsche 911 has the same engine and transaxle layout and people have swapped Tesla Model S drive units into them (replacing both the engine and the original transaxle); of course the Fiat would need a much smaller drive unit. Yabert put a Chevrolet Bolt drive unit in a VW van (again, the same original engine and transaxle layout), but that's still three times the power that the Fiat 600 needs. Yabert provided an image of the Bolt drive unit in the space originally occupied by the VW transaxle, leaving the entire engine bay available (which is needed for the inverter, charger, etc).

There are other mechanical solutions which eliminate carrying the whole original transaxle around in a car which uses only one or two gears of it, but it's more design and fabrication effort (and of course more cost, since the existing transaxle is free) and the existing transaxle is light and small enough that most conversions would just keep it.

 

[brian_]

I found a company that already sells the module with a cell tap that works with the Orion BMS. its Stealth ev, i think i will use some components from there. and they have the 3D designs of a lot of tings which is great!

Stealth EV is listed by Orion (in the first document that I linked) as a supplier of wiring adapters to connect the Orion BMS to the Tesla modules.

 

[alanfuertes]

I just found this:

Seems to be a school project.
Where do you come from? It might be an advantage (legally) to use certified parts from an OEM, such as a complete drive unit.
If reduced power does not come with a weight benefit, you should stay with the 63hp. Make the voltage as high as you can, this keeps current (Amperes) low and you save cable diameter (= weight)
100km appears reasonable, my Mini (660kg) does this with a 90kg battery pack made of 18650-cells.

Markus

Hey! Im the driver of the first video and thats my channel!!!

haha

 

[alexandrept21]

Stealth EV is listed by Orion (in the first document that I linked) as a supplier of wiring adapters to connect the Orion BMS to the Tesla modules.

Do you know if the Stealth EV 3,3kw charger + 1kw DC/DC converter would work on my 72V battery system?