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The Electric Mercury Cougar Conversion

1819 Views 19 Replies 5 Participants Last post by  AvoidingZombies
I am converting my 2001 2.5L Mercury Cougar to electric using a mix of parts from the Nissan Leaf, Tesla Model S, Toyota Prius, Ford Focus Electric, and Honda Civic Hybrid. The goal is to make a fun city car to rival the range and performance of my 2012 Ford Focus Electric (which is currently stripped out a bit in the back for fun), and eventually surpass it in both when I can get my hands on a battery pack over 60 kWh. Here's most of the parts I have:

Car: 2001 Mercury Cougar V6 - $450

Motor: 2011 Nissan Leaf (EM61) - $430

Inverter: 2011 Nissan Leaf Inverter with P and S (Paul Holmes) brainboard/ logic board. - (Inverter): $250, (P and S Brainboard): $340

Coupler: Brat Industries Nissan Leaf Coupler. Still need to take to machine shop and have the center piece of clutch plate pressed in. - $221

Adapter Plate: Will update when purchased.

Transmission: 2005 Ford Focus MTX-75. Plan to swap in the differential and ring gear from the Cougar MTX-75. - $258 (includes diff. and ring gear price)

Onboard Charger: 2014 Tesla Model S Onboard Charger (Gen 2, Part Number: 1014963-00-G) - $430

DCDC Converter: 2011 Nissan Leaf DCDC Converter - $250

Battery: 2012 Nissan Leaf 24 kWh Battery - $2,110 (from Battery Hookup )

BMS: For now, using the BMS/LBC that came with the battery pack. May eventually go to Orion BMS. - $ (refer to Battery)

Precharge Circuit: Reusing what came with Leaf battery

Charge Ports: Currently going to use the J1772 and Chademo that came with DCDC Converter, eventually switch to CCS. - $ (refer to DCDC Converter)

Battery Case: 2 Honda Civic Hybrid boxes (one can hold half the battery pack), but may just cut the Leaf case and use that instead. - $50 from picknpull

Vacuum Pump: Volvo Vacuum Pump. Also have the option of using the spare Focus Electric Vacuum pump I have. - $25

AC Compressor: Leaning towards my spare Ford Focus Electric compressor, or a Nissan Leaf compressor.

Power Steering: Update when bought, probably going to get the Opel Zafira B pump.

"Gas" Pedal: Toyota Prius Pedal - $15

Rotors: Drilled/Slotted Rotors, brake pads, and shims from eBay. - $244

CV Axles: Mercury Cougar 2.0L manual trans., still need to buy extension piece and bracket - $152

Suspension: Vogtland Lowering Springs, RockAuto Struts, Strut Bellows, Strut Mounts, Stabilizer Bar Endlinks, and polyurethane sway bar bushings. - $636

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I plan to update with what I've done so far over the coming days :)
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Are you going to take out the fuel tank and use it for some battery storage or just use the rear storage where the spare would be.
Are you going to take out the fuel tank and use it for some battery storage or just use the rear storage where the spare would be.
The area where the rear seats are will be used for battery storage, along with directly under the seats
(where fuel tank would be). I would like to keep the trunk area battery free, and keep the batteries low and closer to the middle of the car. Half of the battery pack can fit inside one of the cases.


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Now for a little story time. I picked the Cougar up for $450. The rear passenger tire was separating, the interior had been torn apart and stuffed in the trunk (owner claims he was doing a part out of the car, and decided to just sell it as a whole instead), the engine had a vacuum leak, the front bumper was torn, spoiler was torn off, the poor car looked as if it hadn't been cleaned in years, and the automatic transmission couldn't shift past 2nd gear. I got the car back to my house, and began the process of giving it a much needed bath, along with reassembling the interior. The last 2 pictures are after I cleaned the exterior.

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The first picture is how messy of a condition the interior of the Cougar was in. It took some time, but I eventually got it clean. I also began cleaning and putting back on the interior pieces. While cleaning the exterior, I ran into quite a bit brown widows, so I doused the underside of the car with bug spray to kill the critters. With the rear seats out and eventually the gas tank, I plan to put the battery modules in those two areas. There is also the possibility to put batteries in a similar layout to my focus electric, which is directly behind the rear seats, between the rear struts.

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Arrival of the 3 Phase Permanent Magnet Alternating Current (PMAC) Nissan Leaf electric motor, codename EM61. Pretty hilarious a motor the size of a pale of cat litter can produce 600 HP with the right inverter and battery :LOL: . The Nissan Leaf inverter also arrived that week, so I gave both a good cleaning/sanding. Buying parts from wrecked EVs is a vital way of bringing down the cost to convert a car to electric, as it can be the difference from spending $25,000+ on "off the shelf parts" to convert a car, rather than spending less than $7,000-$10,000 using parts from wrecked EVs. Basically all OEM motors/inverters from automakers have liquid cooling built in and can produce much more power than what they're rated for without breaking a sweat. The most commonly used ones are from the 2011-2012 Nissan Leaf, 2013-2017 Nissan Leaf, Gen 3 Toyota Prius, and Tesla's, though the Leaf setup is probably your best bang for buck. Tesla motors and inverters can produce insane power, but they have an insane price tag to match, and the Prius inverter is cheap, but can't make decent power without beefing internals. If I would've bought a similar powered 3rd party AC motor and inverter instead, I would've end up spending well over $8,000 just on that alone (see last picture). Instead I spent around $1,000 for the motor, inverter, and custom inverter brainboard.

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This is when I began de-ICEing the Cougar. I drained the coolants, and began the removal of the exhaust system, intake, exhaust heat shield, gas tank, and EVAP canister. Also bought some new gas struts for hatch so it would stay up. And once again, had a run in with a couple brown widow spider survivors.

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Arrival of the standard J1772 charge port (small orange cover), Chademo Charge port (big black cover). Now for some terminology:

EVSE: The correct term for what everyone calls portable chargers for EVs. EVSE stands for Electric Vehicle Supply Equipment. The first picture is the portable type of EVSE. This is the kind you keep in the car just incase you need to charge when your out and about, or don't have a wall mounted one These are usually 120 Volt EVSE or 240 EVSE, and sometimes both!
The second pictured showcases the wall mounted ones. These can be hardwired to the circuit breaker, or they'll have a cord that extends to a suitable outlet (usually 240 Volt outlets)

Onboard Charger: This is the actual charger. When you plug the EVSE into the car, this is what takes that electricity from the 120 or 240 Volt outlet from your house, office building, grocery store, etc. (which is AC, or alternating current), and converts it to DC (Direct Current) for the battery pack. Batteries are DC energy storage devices, they can not store AC. The onboard charger is also liquid cooled. I have a photo of my Focus Electric onboard charger so you can see what it is, see last picture.

Charge ports:
The small orange one, J1772, is the standard AC (alternating current, not air conditioning 🤣) port used by all EVs, except Tesla's. It's accepts Level 1 charging (allows the EVSE to be plugged into a regular 120 Volt household outlet, like what your phone charger, laptop, TV, microwave, etc. plug into. Pulls no more than 1400 Watts, a little more than a microwave) and Level 2 charging (a.k.a allows you to plug into a 240 Volt outlet, such as what your dryer plugs into. This can slice your recharge time in half or more, depending how many amps the 240 Volt plug can take, what the onboard charger and EVSE is rated for).

The one with the big black cover, Chademo is a DC (direct current) used by a few models of EVs. Most modern EVs use CCS (Combined Charging Systems, another type of DC port). Anyway, Chademo accepts level 3 charging, or better known as DC fast charging. These are the stations you'll see more of in public in the coming years (from companies like ChargePoint, EVgo, ElectrifyAmerica, Volta, etc.). It is capable of charging the Nissan Leafs battery from 0-80% in 30 minutes or less. The Chademo plug takes 62 kW DC (500 Volts DC, 125 Amps) directly to the battery, bypassing the onboard charger. In newer EVs, some can recharge in as little as 15-18 minutes (Hyundai Ioniq 5) with DC fast charge! In the second to last picture, the plug with the red and orange connectors is Chademo. It is easy to distinguish since the High Voltage DC connections just have positive and negative.

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I ordered 3 different brain boards, but ended up going with a pre-built one from Paul Holmes. The board allows you to control the Nissan Leaf inverter, giving you access to parameters such as data streaming, adjustable min/max regen strength adjustments, adjustable min/max motor amps, adjustable min/max battery amps, max rpm (rev limiter), precharge circuit time limit, raw throttle data stream and more. The board is easy to replace too, you just:
  1. Remove inverter top cover.
  2. Unplug the 5 small black connectors and 1 big gray connector.
  3. Remove the 6 screws holding down the stock brainboard.
  4. Swap in new brainboard, screw it back down, and reconnect the connectors.
For the gray plug's connector, I cut a door wire harness from a Mazda 3 at the picknpull and used the wires to make a test connector for the board (The correct wire size to use is 22-24 AWG for the connector. I used a gauge that was too big in some of the ports, so it'll look stretched for some). I don't have a crimping tool, so I used needle nose pliers to crimp the wires to the pins. As for what pins control what, I'll explain that later on.

Another thing to keep in mind when going with a Nissan Leaf inverter and Leaf motor for a conversion, there are quite a few options for gaining control of the inverter:
  • OpenInverter- One of the only boards (besides Paul Holmes) that lets you access more power from the Nissan Leaf motor/inverter. Even with a stock inverter you can achieve 180 HP with the board. Supported by a very strong and growing community forum page.

  • EVBMW- open source VCU for EV conversions. Has support for CCS fast charging via a BMW i3 LIM Module. Does what Paul's board can do, along with having CAN support, Wifi support, BMS limiting, temp derating, a User Interface, auto charge start/stop, and more! I may switch to this board later on. More info on OpenInverter Wiki.

  • ThunderStruck- Rather than replace the brainboard, replaces the Leaf VCU. It will run a Nissan Leaf setup at stock power. Great for low powered conversions.

  • Resolve-EV- Requires all major components from the Leaf (motor, inverter, onboard charger, water pumps, "gas" pedal, etc. It all will have to come from a Nissan Leaf). Acts a VCU/ECU to also control brake lights, reverse lights and can make your conversion accelerate faster than what the motor can do stock.

  • Honorable Mention Arlo's Electric CRX- a forum page of someone who swapped a Nissan Leaf motor and inverter into a Honda CRX, beefed up the internals of the inverter, and is now pushing over 330 HP. He and a couple others started Axiom, where you can follow along the development of their 100+ kW AC motor controllers. Also, if you read through his forum, you can possibly replicate what he has done.

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With the arrival of the 24 kWh Nissan Leaf battery pack, I was able to begin disassembly of it for testing my motor/inverter. Breaking down a potentially 400 Volt battery that can generate 500 amps (so can produce over 217,000 Watts!) was a little nerve racking though. After disassembly, I took it to my room so I can run test on the motor/inverter. Now for some more terminology:

  • Max Continuous Discharge- Max amount of power you can make a cell produce without severely overheating it. This is the rating your battery pack should be built around.

  • Peak Discharge- Absolute max amount of power a cell can produce. Reaching this point can only be done for as little as a couple seconds, or as long as 10 seconds depending on the cell chemistry/setup. Reaching peak discharge often is not recommended, as it can shorten a batteries life span and potentially cause it to overheat.

  • Balance Charging (Balancing)- Balance charging is vital for lithium batteries connected in series. It is used to regulate the charge on the cells and make sure they receive an equal amount of charge. Without a Battery Management System (BMS) to balance cells, there is a chance a cell in a series connection will get finished charging before the others, and rather than having the BMS cut charging off for that cell, it will instead keep charging past it's rated max voltage. This can lead to a battery fire.
Battery Pack: Came with the required wires, thermistors, and Lithium Battery Controller (LBC). Fully charged, the 2011 Nissan Leaf battery pack is rated for 403.2 Volts, 64 Ah. This comes to 24,000 Watt Hours, or 24 kWh ( You find this number using Ohms Law, which sates if you multiply your Volts by Amperage, you'll get the Wattage. So 403.2 x 64 = 24,000. Now since 1,000 Watts hours is equal to 1 kWh, you'll need to divide the Wattage answer by 1,000. So 24,000 / 1,000 = 24).
-The pack can produce a max continuous discharge of 240 amps, and a peak discharge of 540 amps. Once again, using the same formula above (Volts x Amps = Watts), you can produce 96 kW (128 HP) MCD and 217 kW (291 HP) PD.
-There are 48 battery modules in the battery pack, and each module contains 4 individual cells. In total, there are 96 cells (48 modules x 4 cells per module). Each cell is rated for 2.8 Volts fully discharged, 4.2 Volts fully charged, and 32 Amp hours of capacity. Each module is a 2 Series, 2 Parallel connection rated for 5.6 Volts fully discharged, 8.4 Volts fully charged, and 64 Ah. The middle tab of each module is used for balancing via the LBC.

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For motor testing, I began by connecting the wires from my custom brainboard to their designated spots. Next, I took a 120 Volt AC to 12 DC power supply, connected pin 38 to the positive terminal of power supply, and pin 20 to the negative terminal of power supply, and plugged the power supply up to the wall outlet. Within a second or two I hear the clicking of the relay, followed the contactors closing.

Link to video of contactor testing: New video by Aaron Green

  • Pins 1 - Pin 11: These pins are for the motor resolver (12 Volt plug on bottom of motor)

  • Pin 14: Control board Ground

  • Pins 17, 19, 20: Ground for 12 V input power (can use these ground wires for the accelerator pedal, brake input, contactors, relay, etc.)

  • Pins 21, 23, 24: USB cable connections. Can take a phone charger cable, cut the end that goes to the phone off, strip it back, and connect corresponding wires (red wire is pin 21, USB VCC. Green wire is pin 23, USB Data+. White wire is pin 24, USB Data-.

  • Pin 26: Forward/Reverse Pin, changes motor direction.

  • Pin 27: 0-5 Volts analog brake input

  • Pin 29: 0-5 Volts analog throttle (this pin goes to the wiper 0-5 Volts pin on a Toyota Prius accelerator pedal)

  • Pin 30: +5 Volts from control board. This used to send a constant 5 volts to either the analog brake or analog throttle.

  • Pins 32, 34: CAN Low (32) and CAN High (34). Canbus doesn't function on 2011 Version of Paul's board.

  • Pin 35: Percharge Out+. Powers the precharge relay in the precharge circuit.

  • Pin 36: Contactor out+. Powers the positive coil of the main contactor in the precharge circuit.

  • Pin 37: Contactor out+. Powers the positive coil of the main contactor in the precharge circuit.

  • Pin 38:+ 12 Volt input power

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With 8 modules connected in series, I did as followed:
  • Connected battery pack to the Precharge circuit.
  • Precharge busbars to the inverter (DC side).
  • Leaf motor to 3 phase AC side of inverter.
  • Checked connections for low voltage side of precharge circuit, Prius Pedal, motor low voltage side, and connections to the 120 AC to 12 DC power supply.
I then plugged the power supply in, waited for the precharge circuit to close the contactors, pressed the pedal, and got the motor spinning. The modules are connected in series, generating 60 volts.
Warning: Do not be like me, use thicker wires for testing these batteries. I learned my lesson a little later at a much higher voltage😅.
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Test of the rev limiter parameter. Just one of the things that can be adjusted on the P and S brainboard via the Realterm application.

So does that mean you can control basically in simple terms make the motor be able to push the car faster that what the prius was able to do. In terms of acceleration.
So does that mean you can control basically in simple terms make the motor be able to push the car faster that what the prius was able to do. In terms of acceleration.
This will be quite a bit quicker than a Prius. With the custom logic board, I can increase acceleration by adding more cells in parallel, as this increases the amps I can pull from the battery. More amps means faster acceleration. On the other hand, increasing the voltage, or more cells in series, means the motor will have a higher top speed (or higher max rpm).
I love the idea of an electric Cougar, but I don't love the idea of losing the back seat to it. :(

Ah, who am I kidding, I'd never have the time to do the conversion anyway.
I love the idea of an electric Cougar, but I don't love the idea of losing the back seat to it. :(

Ah, who am I kidding, I'd never have the time to do the conversion anyway.
It was either that or the trunk and I'd much rather keep that weight and space consumption out of my cargo area. As a 23 year old with no kids, the back seat delete won't matter for another potential 8-10 years :LOL: .
As a 23 year old with no kids, the back seat delete won't matter for another potential 8-10 years :LOL: .
I don't have kids either, but for me it'd be "where would the dog ride?" Good luck, though!
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Awesome build!! I’d love an update. Thought about an EV conversion b4 but I’m so happy to see someone making it happen. Curious on how you mount the motor to the tranny. I assume you plan on keeping the clutch, or are you making it clutch less?
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