EB324 Controllers keep blowing up! Problematic controllers

[Scott]

You joined the 70mph club on 125V with the EB324 controller I built

I am so disappointed I really thought I was there! Although don't get me wrong I am very happy to have passed my goal of 60 mph when I started thinking about this project 2 years ago although, I'm pretty sure 70 mph is possible and I will get there soon.

Unfortunately my CA is not displaying the correct max speed and I only hit 61 mph on that specific “69 mph” run. However I did hit 64.4 earlier that day.

I have since then hit 65.9 mph but my GPS did not work on that run. After riding around a bit I hit 64.9 mph on the CA (while riding, not looking at max speed) and my GPS showed 65 mph. I really want to hit 70 mph so I am going to look into some minor aerodynamics to hopefully get me there.

For controller temp, same results at 30s on 125 volts, on my 65 mph run controller heated up to 30 C then started cooling down once at top speed and still full throttle. Then when I let off the throttle my controller cooled down to 25C in 12 seconds (time it takes to the CA to cycle through temp, miles, Ah). I absolutely love the cooling design of these EB324 controllers. Personally looking at the guts of the EB324 controller it looks really clean and nice on the inside compared to the EB224 controllers. It even looks smaller even though I'm pretty sure it is not.

 

[zombiess]

You are probably maxing out the amps. My simulation predicts you need around 150a to get to 70mph. Would you like to up the power a little more? If so we can bump your amp settings up. Heat is a non issue on these controllers. I will be trying 200a/200a at 100v on mine soon, need to mod the shunt to stop it from cutting out at 150a. You will hit this same issue soon if we up the amps much more.

 

[Scott]

You are probably maxing out the amps. My simulation predicts you need around 150a to get to 70mph. Would you like to up the power a little more?

I could up the power more but, when I lean over the bars to be as aerodynamic as possible the motor only draws 60-70 amps at top speed.
For racing at Laguna Seca and Pacific Raceways for Silent Thunder I was thinking about buying a few 2s lipo packs to boost my voltage to 134v. From what I understood I thought 135 volts was safe although, you mentioned that I should not go higher than 30s?

edit:
Also I forgot to mention I went up the long hill which is around 3-4% grade at around 30 mph or so and the controller got up to 34 C at 17-20 amps. Then when I got to the 6% grade part I pinned the throttle and hit 55 mph and the controller got up to 40C, then I flipped my switch to check motor temp and it was 111 C!!!! The motor was pulling 130 amps then slowly went down to 80 amps for the 14 seconds I had the throttle pinned.
3 minutes after the side covers on the motor were just slightly warm once I got to my destination. When I left a few hours later the motor covers still felt a little warm.

My conclusion is unless a cromotor is vented (which will probably not help enough) or water cooled (with a radiator and pump like what Keyne did) the motor will be toast before or by the time the controller gets too hot.

 

[zombiess]

My conclusion is unless a cromotor is vented (which will probably not help enough) or water cooled (with a radiator and pump like what Keyne did) the motor will be toast before or by the time the controller gets too hot.

Yeah, with a enough controller the motor is the weak link and that's saying a lot considering most people are running 10-15kW into them which is 2-3X their rating and zero thermal failures. I don't run a thermal probe yet and I know I have had it well over 100C, but no smoke, no burning smell, just toasty covers after sitting for 2 mins. Always good to do a low speed cool down after beating on it HARD, what you are doing is minor compared to the abuse I give mine

 

[windtrader]

It's been over a year on the controller experiments. What happened? What are the reliable controller options now?