Mazda MX-3 electric

[arber333]

I came back to roots and decided to remake my first EV.
Mazda MX-3 that i converted back in 2013. Old build log is here: https://mazdamx3ev.wordpress.com/

Well i decided to remove the old air cooled ACIM motor and install Outlander rear motor in place.
I will use OEM inverter and my ESP32 VCU built to control Outlander inverter, charger, heater and JK BMS.

Some photos of Mazda empty space:

Motor original position:

I will use ID3 modules 6kW8 modules 12S2P in alu boxes.

For battery mount i decided to use 3 plate sandwich. I will use two 8mm plates on the outside for stiffness and i will use 5mm plate and cut it simply by jigsaw to a pattern where coolant will flow from one side to the other. Then 5mm plate will be glued between outside plates and bonded by M5 countersunk bolts.

I will still have to find a TIG welder to weld two 10mm tubes vertically onto one side of the plate for the coolant to enter the channels.
I currently made two 650mm x 460mm plates and put holes for M10 bolts to fit modules from each side of the plate.

[arber333]

Some more photos of motor positioning. I need to get good level position with driveshaft well clear of the frame when car is on lift!!

[arber333]

I managed to install Outlander motor. It is a bit offset, to forward axis, like 5deg probably because of my strange bands mounting contraption.
If i dont like it i will correct it by rewelding those forks.

Next i started to mount inverter and charger. Well the charger mount was already made. I just repositioned it.
For the inverter i made 5mm alu brackets that mount firmly to the chassis. At least 3 mounts to define position in space.

I also put Outlander heater on the side so i can connect and setup hoses.

Next i need to fit the front battery box to those transverse beams and make mounts for cell modules inside the rear box.

[arber333]

I had to make a fitting to fix the charger in place. I simply made a U channel to keep the distance from the front marker.

I made a simple angle fitting for the coolant header tanks. On the left will be coolant and on the right i will use liquid for the heater system.
I think of making another simple extension fitting to fix the coolant tanks in place by the 3rd point.

I got the front battery box made from inox 1.5mm. Dimensions 470mm x 700mm x 250mmIn. Idea was to fit 4 of ID3 12S modules inside here. In the end i couldnt get the bonnet closed so i had to cut down the last 50mm to taper down the box. This means i wont be able to fit full 4 ID3 modules but only 3 of them. I will be able to fit complete mount of 4 in the back though.

[tom91]

You looking to reuse OEM bms slaves? Using less then 4 requires some testing to figure out if the balancing works correctly.

[arber333]

You looking to reuse OEM bms slaves? Using less then 4 requires some testing to figure out if the balancing works correctly.

No i dont have any BMS from VW. I will simply use JK BMS and ESP32 VCU as master control. I already wired 3 12S battery modules to 2 BMS modules but i will have to appropriate another 12S module in the 5th BMS module. This means i will have to program my VCU to modules 4x18S and 1x12S.

I still havent decided if i will need liquid cooling or if the ALU plate will be enough of a heat sink...

[arber333]

There is a lot of small tasks like make a third mount for coolant headers, cable clamps etc... and i didnt have time to photograph everything.
What i did is take photos of battery mounts within front battery box. I had two inox C profiles made and i drilled holes for M8 bolts to mount those profiles inside the box.

Later i drilled two moere holes on each side so i can mount the alu plate with battery modules attached. Since i will fit bolts in vertically i needed to weld M8 nuts from the underside of the C profiles. Later i might have to drill large holes in the profile vertical wall to be able to fit cables or sensors...

That way i will have nut held from the underside and all that will be required would be to torque the M8 bolt.
The arrows drawn on the plate let me assemble the shelf easily as i allways know the direction.

[arber333]

Another update...
I will add the links to my site here not to spam with photos in dual posting.
I managed to install coolant and heater piping. The idea is to feed both systems from the same header tank. I used a lot of copper piping as i can solder it easily at home. Just need some plummers paste, thick solder and copper piping.
I also salvaged a compact chiller from old Fiat 500 car and fitted 80W cooling fan by its plastic wraps. I still cant belive those plastic things fit into the chiller so efficiently.
This way i will have more compact (less hoses) system in the front of the vehicle.
I am still thinking of fitting the Tesla Gen2 charger to this car for 3phase charging, but it would significantly lengthen the build. I need this project soon so i will settle for 2phase 6kW charging power. Later on i could add fast charging...
https://mazdamx3ev.wordpress.com/2023/1 ... ng-piping/

The other thing is the wiring of systems in front. I made a single CAN line for VCU – CHARGER – INVERTER – HEATER – and leave the last connector for CAN bus termination or to add one Volvo Eltek charger in the end. Of course there will be 12V lines and relays for Enable or charging signaling etc..
The idea is nice and compact wiring up front, something that is now called Full Mux where you only have power supply and digital signals to drive your devices. https://mazdamx3ev.wordpress.com/2023/1 ... omponents/

Next i need to test my CAN lines for messages from VCU and devices.
Stay tuned

[arber333]

Almost forgot... i cut and welded Mazda and Outlander shafts.
Writeup is here:
https://mazdamx3ev.wordpress.com/2023/1 ... iveshafts/
I will add some photos still...

EDIT: There is a lot of good info on how to splice axles here:
https://www.youtube.com/watch?v=G7iTT-RFfo0

[arber333]

To connect DC to inverter i used 3d printer and made several DC glands designed by crasbe so thank you .
I set this up to fill 75% in PETG. I printed one black gland and one violet - its what i had in PETG - to differentiate DC+ and DC-.
I got a couple O rings 18mm by 3mm thickness to seal the opening. It is quite a tight squeeze because O rings are medium hardness and i cant get any softer version.

I connected 35mm2 cables in those glands.

I connected motor cables, yes i luckily got good motor cables with sealed covers.
On the bottom there are two secondary DC connectors that lead to the heater and charger. I like MC4 connectors so i made those connections removable and connected shield to the casing. Every part will be connected to another by grounding 6mm2 cables.