David's 2001 Civic EV (80-100 mile range; 65+ MPH; 8 second 0-60)

[Cobb]

I tried the 110 vs 220 on my enginer charger and everything stayed the same. Same fan rpm, same charger output, same recharge time.

[TheSGC]

Originally Posted by Astro

Is that the inbuilt fan in the charger?
So at double the rpm the air flow rate adequate. So at least you know the air flow rate you need.
Is it possible to crack open the charger and replace the fan with a higher flow version? So that you get a higher air flow rate at 120v and overkill air flow at 220v.

If there isn't enough room inside the charger for a higher flow rate fan then maybe remove the internal fan and bolt a higher flow rate fan to the outside of the casing.

The fan is mounted onto the fins on top of the charger. It believe its a 220v fan that just runs at half speed at 120v. There is space along the fins to add more fans, so I'm thinking about adding two high CFM 12v PC fans that get turned on then the EV gets plugged in.

[TheSGC]

I got started on the A/C today. I got the treadmill motor bolted in and purchased a new belt to use with it.

I was able to do some testing and I found the best setup was using 36v, pulled 20A from the lead acid test pack I used. The A/C blew really nice cold air, so now I need to build a small motor controller to use my 144v battery pack to control it. I also need to figure out how to get the car's ECU to activate the clutch for the A/C compressor. I had to put a jumper in the relay position to get the clutch engaged for my test.

Tomorrow I am going to run the A/C for 30-45 minutes to see how the little treadmill motor holds up. I did it for 10 minutes today and it barely got warm, so I have hope that I won't burn it out.

[mechman600]

Nice work!
To control the motor, I would use a small controller like you said. I used a Kelly KDS72100 (72V/100A) controller to control the field current in the original SepEx motor in my car. It never let me down. However, these small controller are only available up to 72V, so I'm not sure what you would do about that.

[EDIT: Oh right....you will probably build your own!]

As far as controlling it goes, the original setup is simply an ECU triggered relay that switches the A/C clutch on. I would use the same relay, but instead use it to switch the TPS circuit in the A/C motor controller. Set the controller up so that an open circuit (or high resistance via relay pin 87A N/C through a resistor) in the TPS circuit is 0% throttle and a closed circuit (ECU commanded "clutch engaged") through an appropriate lower ohm resistor in the TPS circuit is 100% throttle.

[nemo]

Was just thinking how nice and efficient to have full AC output while stopped, not relying on engine RPM to control output. Combine that with some sort of thermal control to cycle the compressor off and on just so much better than engine driven.

[TheSGC]

I am building my own controller, something around 200v and 50a to handle this motor or any other motor I would use in the future. I'm hoping to get a prototype working over the next week or so, then possible manufacture some PCBs with all the components condensed.

While I could mount the A/C compressor to the Warp 9 rear shaft and change the location of my RPM sensor, I really want the A/C for when I am stopped or in traffic. And I am estimating that the A/C setup will only take 5A from my main pack so it will have minimal effect on my range.

[mechman600]

If you install valving on your A/C system to turn it into a heat pump for heating in winter, it might be a more efficient way of heating than your current setup.

[TheSGC]

I setup my A/C to do a test and after ~15 minutes the little motor started to burn up! It appears that the fan for the motor is actually missing, but I don't know how much that would have helped.

So now it's back to the drawing board for the A/C. I am now going to look at 3 options:
1: Get another, stronger motor, maybe a 3 HP that will run of 180v and under 3,000 RPM so it can just run off a contactor.

2: Use the rear shaft of the Warp9 to run the A/C. This is probably the fastest solution, but I would need to measure the space to see if a pulley would fit.

3: Get a Prius A/C unit and build a 3 phase inverter for it, so some other kind of electric A/C compressor.

[Daox]

Could you just add a small fan to the motor (shaft)? Run it at a higher voltage, less amperage. Use your belt drive to correct for rpms.

[TheSGC]

Originally Posted by Daox

Could you just add a small fan to the motor (shaft)? Run it at a higher voltage, less amperage. Use your belt drive to correct for rpms.

The problem is the motor is too high of RPM, rated at 6750 RPM @ 130v. I have the smallest pulley I could find welded on the shaft so adding a fan at this point is not an option.

Ideally I would like something rated for 180v DC and runs at 3000-4000 RPMs so I wouldn't need a controller at all.