Paul & Sabrina's cheap DIY 144v motor controller

[jyanof]

Originally Posted by duncan

Hi Guys

I have been driving my car,
I have "lost" throttle four times now - driving normally - then no power
This may be when I have backed the throttle off

The car slows - goes to the side of the road - then I have throttle again and drive of
...
Suggestions???

In addition to other suggestions, I've had issues with the motor over speed tripping at seemingly random times. I traced it to times when the motor is spinning in neutral and I apply power and ease the clutch in (like coming out of a turn). If I dropped the clutch too hard and there was a sudden drop in motor rpm, the controller thought that was an over speed event and shut down for 2 sec.

Obviously, if you don't have the over speed set up, this won't be a problem. But, if you do, maybe disable it for now and see if it goes away.

[amino]

I had a similar experience as duncan when testing my car with a smaller battery pack than normal. It turned out to be the DC to DC converter, which would cut out when the voltage sagged below 75 volts, causing the controller to lose power, usually when the accelerator pedal was released and pressed again.
Adding another battery to the pack solved that.

[duncan]

Thanks amino and jyanof,
I am not using a dc-dc
I just have an auxiliary battery that gets re-charged at the same time as the main battery
I am direct drive with no overspeed limit
(max revs would be 130Kph and the roads around here do not encourage that speed)

I drove the car yesterday - no problems,
I hate intermittent faults!

[timmytool]

jyanof, you don't need to use the clutch at all in a ecar, the motor has no practical inertia so their is no need to protect the dog teeth in the gear box with a clutch.
As you have experienced using the clutch can create problems, also don't use the electric motor without any load on it as it can/will turn into a hand grenade without the speed limiter parameter engage (aka with the clutch in or the gearbox in neutral).

The only real reason for the clutch in a ecar is in case of a controller failure event were the controller fails "on", its like a drive train fuse. In this event the motor will hand grenade but that's preferable to an out of control car.

[jackbauer]

Passing 600amps my clamp meter packed in ........Video in the morning. 17 hours to upload. Gotta love rural Irish broadband

[MPaulHolmes]

I see a chair there. Is that your living room?! haha. I finally modified the code to show either 1000amp or 1200 amp on the uart stream.

[jackbauer]

That is the sofa from my old place now installed in the spare bedroom / electronics lab so I can chill out after the stress of running 1000 amps through some components :

https://www.youtube.com/watch?v=SkpQ4w26tt8

[jyanof]

Originally Posted by timmytool

jyanof, you don't need to use the clutch at all in a ecar, the motor has no practical inertia so their is no need to protect the dog teeth in the gear box with a clutch.

This isn't really on-topic for this thread, but I thought like this, too, until I tried it. Turns out the inertia of a 9" motor IS significant - down-shifting gears took way too long and up-shifting was near impossible.

After 10k miles, I removed the simple coupler and reinstalled the clutch. The car drives a lot better now and I'm happy I did it. Of course, other experiences may be different...

Relating this back to motor controllers, a clutch is definitely valuable for disengaging a runaway motor. Ever since my pseudo-failure, I always have my foot just above the clutch when backing out of a parking spot, just in case...

[camosoul]

Wow... I just read this whole thing... In the first 150 pages I thought I could contribute a lot... Then about page 250, my eyes got glassy... I wish it were more condensed because I know I could learn a lot if I read it again, but I can't afford the time...

I definitely want to buy a kit for the 500A controller, but it wasn't clear to me if it had taken over startup order (precharge resistor, contactor, etc) or not.

I also wanted to ask about a hybrid I want to build. A pure battery electric simply won't work for me. I'm not urban. I'm very, very rural. If I have a reason to leave home, I have an absolute minimum of 50 miles to drive. Usually a lot more. I'm considering a previously battery-filled, but now just a glider with a WarP 9 in it, F-150. I'd like to go multi-generator hybrid with it. But, after rectifying the A/C output, it's still bouncy. Put with that a bank of regular car batteries... Why? To accelerate. Regular car start batteries are made to deliver a pulse, then recharge. It's their purpose and they've been doing it a long time. So, how do I put this controller, those batteries, and 2 or 3 generators together and not blow it up? Overcharge the pack? Rippley DC? Draw down on the batteries during accel and not pop the gen breakers?

I know I can roll it at 45 to 55 mph and pull batter/gen amps in reason. Becoming emissions free, green elitist, etc., is not the goal, nor is it even possible with my needs. What I'm trying to do is create a better drive system that I can work on in the sticks and dirt. A small generator motor I can rebuild in a few hours. And, the vehicle is still usable due to redundancy and modularity. Just replace a generator. Fix it while still being able to drive it. When you live out here, that's very important. If I 'get stuck' with a dead car, I'm seriously screwed! It's a step in the right direction, waiting for batteries to grow up.

I currently drive a VW TDI w/ tall skinny tires and an econo-minded ECU chip. It has 360,xxx miles on it. Over 50mpg. But it's time for something else... And I want it to be a serial hybrid F-150 rolling on 35in tires... I'll miss the crazy deep triple digit speed that TDI can get up to, and I'll probably miss the 50mpg, too... But I need something with redundancy, easier maint/repair and a drive train I won't have to worry about in this lifetime, which also has some payload capacity.

Who can throw me a bone?

[duncan]

Hi Camosoul
Not so much a float as an anchor!
A series hybrid is bad news
Each time you convert energy the gods of engineering take a bite
Diesel - power 30%
Power - road 90%
Total - 27%

Serial Hybrid
Diesel - power 30%
Power - electricity 85%
electricity - power 85%
Power - road 90%
Total - 19.5%