35 amp controller

[BKing]

Does the larger amp controllers like the 35 amp show over 1000 watts during initial acceleration but roll off power as you get to 15mph and higher?

 

[AHicks]

Does the larger amp controllers like the 35 amp show over 1000 watts during initial acceleration but roll off power as you get to 15mph and higher?

This is going to get back to the type of cadence system - power based vs. speed based. When talking about the 35a KT controller, you have a say in the matter, which way you prefer, as it's capable of either. MOST riders will prefer the power based (torque simulating = enabled in KT speak). When set that way, the 1000w will be available at any speed, from -0- to as fast as you want to go.

To my knowledge, this is unique to the KT controllers, as well as the Bafang mid drive controllers (BBSxx and Ultra). Bafang let's you make this same call.

 

[BKing]

I have the 35 KT and didn’t like the groaning noise at startup so I shelved it. Now I’m trying it again but still groaning and with P3 set to 0 or 1, both are rolling off in wattage at higher speeds to about 620 watts. I don’t think the Rad 48v battery is sagging, if it was going to sag it would do it sooner. It’s probably a function of the DD motor since everyone seems to say theirs does not do this. The C2 setting for motor phase seems useless, I tested every setting and nothing changes.

 

[AHicks]

Does the RAD direct drive motor use the same round plug found on the Bafang geared hubs, or did you have to get "creative" for that connection? What I'm wondering is if your wiring is set out of phase (not wired correctly).

My 1500w direct drive was nearly silent on the 35a KT, unless really accelerating hard, and then it could never be called "noisey".

How much noise are we talking about here?

LCD3 display, or LCD8?

If you have a minute, jot down all of your P and C settings, and I'll go through them. Second set of eyes never hurt a thing.... -Al

 

[BKing]

Plugs are all the same as Rad.
No noise if run unloaded on kickstand.
Radcity 2019 DD
35 amp controller without the tail light.

P1 46 = 46 magnets x 1 gear.

P2 1

P3 1 = full throttle available on all PAS

P4 0 = throttle available on startup.

C1 6

C2 0 = motor phase, tried all settings.

C3 1

C4 0

C5 10

C6 4

C7 1 = cruise on

C8 0

C9 0

C10 N

C11 0

C12 4

C13 2 = regen medium

C14 2 = medium PAS scaling.

 

[AHicks]

Only one difference between your settings and my notes would be my notes show P2=0 Might be worth trying, but I doubt it's going to change your issue any. P2 is more about speedo calibration I believe.

So a sine wave controller is supposed to provide smoother power to the motor for near silent operation. If you have ever heard a DD running on a square wave controller, I would describe that noise as a ringing noise that gets louder as the load on the motor increases. I have to wonder if that's not what you are hearing?

If you think that may be the case, a call to Bolton may be in order. Tell them about your issue, and maybe ask for some detailed info to convince you that you did indeed receive a properly functioning SINE wave controller. I'm thinking that's where the issue is..... (the controller). It's either a square wave, or it's not functioning properly.

-Al

 

[BKing]

I have a motor extension cable with part of it bare so voltages can be checked. I’ll dig out my scope and see what it is. I didn’t buy from Bolton, would have but I don’t think he had these when I bought mine. It doesn’t squeal but more like vibrating groaning sound. Not sure if it will fry my motor over time.

 

[AHicks]

I'll bet you've received a square wave controller. KT had both square and sine for a while.....

 

[BKing]

Yep, square wave 52 VAC peak to peak unloaded on each motor phase.
Red wire has 4 VDC vs 4.9 VDC on the Rad stock controller.

 

[rad-ical]

I have the 35A controller on a 2019 Radcity in just about exactly the same way as you BKing, yes it emits a slight groan upon startup at maximum load. Yes it starts out pulling over 1000W ( nearly 1200W actually) and then this then reduces as your speed increases and less power is needed even with maximum throttle or PAS level 5. I consider this normal. I'll add to the stream of conjecture here that my thought is that at over 1000W we are asking a lot of a nominal 750W motor that is far more likely a real 500W. I think it is complaining at being pushed beyond what it was born and trained to do. I just try to take it gently with the throttle or high PAS levels when pulling away from a standstill and it has worked just fine. The motor does not get hot, nor the controller. In fact I just bought a 52V battery and even that seems to be working fine. Not much more speed, but the 20Ah capacity is very welcome.

 

[BKing]

I ride a lot in hot weather and with my stock controller the motor gets very warm within 8 miles on the rides where I do 22mph. Flat ground and PAS 3 with some throttle too, 245lbs. The Rad DD is 500 watts and programmed to only get 750 when the battery is full and tapers off with speed. You can stress it on steep hills so the manual says not to use more than 500 in certain cases. Rider weight is a very big deal with any ebike so it’s difficult to decipher some posts about performance unless they post their weight. I take the bike to places with some hills too. I think I need a sine wave controller and geared motor. I have a spare battery so probably will just carry it or maybe wire it up in parallel.

 

[AHicks]

Yep, square wave 52 VAC peak to peak unloaded on each motor phase.
Red wire has 4 VDC vs 4.9 VDC on the Rad stock controller.

So there's no doubt that answers that issue.....
The 4v and 4.9v is just used on the hall sensors. I doubt seriously it will have any effect on performance. -Al