Cellman's Infineon controllers, soft start???

[alfantastic]

I'm running a latest model, Cellman Infineon 9 fet 30A controller, with a rear MAC 500w 10T. This is connected to a Ping 48v 15Ah battery.
Whilst it's not the last word in power, peaking at 1500w, I was wondering the following about the controller.
I read that some members can suffer from huge, grip breaking torque, even at this modest power level. Making the bike a bit twitchy on loose ground from start-up.
My set-up seems to ramp up nicely until around 15mph, then there's a good torquey pull until the max at 24mph.
At no stage does the rear break traction.
Looking at the CA from WOT at standstill, It never dumps the full 30A from WOT as it moves off, but peaks around the 15mph mark. Then it settles down again as the load settles.
I was led to believe that a motor will draw max current from standstill, as It tries to reaches its normal operating speed.
Note, this test was done on flat ground with little wind.

I was wondering If the latest generation Cellman controllers are software programmed for a soft start/gentle ramp up, for better driveability?

[HombreNeuvoElectro]

It would be interesting to know if this is the case since i am considering controller options at the moment.

This is what is turning me away from BMSBattery controllers. They seem to dump full power from a standstill KU93, KU123 etc..

For this reason and CA Connectivity i am looking at infineon controllers myself and would be interested to know if this is the case with these controllers. I do a look of city riding and full power from a standstill do not seem very safe. I also have not found and good information on controlling the power delivery on other controllers. Directions accpeted to good threads

What power is delivered from a standstill?

[alfantastic]

It's difficult to ride and keep an exact eye on the CA, but I reckon it only dumps half of the controller max at standstill.
It would be nice to see a graph of exactly what is going on at any one point in time.
I do believe the Cycle Analogger does this, and may be something I buy next.
In real world terms, opening up full throttle at standstill provides a seamless wave of smooth acceleration.
No breakage of traction, even on slippery surfaces, although I am still careful when opening up the throttle on tighter turns.
I do have MTB knobbly tyres though, so I don't know if commuter smooth tyres would be entirely different.
I would definitely recommended this controller for a commuting vehicle and the direct CA connection is a bonus.

A friend of mine has also been running Bmsbattery controllers with Bafang BPM's.
He says too, that they tend to dump full current very quickly into the motor, making for a twitchy ride.

[dogman]

Seems like I vaguely recall something about cellmans controllers for the Mac having a softer start. Easier on the one way gear inside or something.

I could be wrong. Also it depends on the load, as I went into slower speed windings I saw lower spikes on starts than with faster motors. It could just be that a gearmotor never stalls as much which is when you'd see that big amp spike.

Do an uphill standing start on steep enough a hill, and you should see more amps on a start.

[neptronix]

AFAIK, they do not.
He could have tuned them for a lower phase amp - battery ratio recently - very possible.

[Jeremy Harris]

AFAIK, they do not.
He could have tuned them for a lower phase amp - battery ratio recently - very possible.

Sounds like the most likely reason to me. Setting a lower phase current will have a greater effect at low throttle settings.
AFAIK there isn't an option to programme a soft start into any of the cheap Chinese ebike controller, only some of the higher end ones, like some of the Kellys, the Sevcons etc. The only cheap end soft start controllers I know of are the old Infineon ones, that used the Infineon XC846 chip that had a pre-programmed throttle ramp (that wasn't good), but they've been out of production for a couple of years now, since Xiechang changed to using another chip from a different manufacturer.

[voicecoils]

If it does 'soft start' or have a delayed throttle ramp up rate, it could be quite beneficial in saving your MAC's internal planetary gearset or freewheel from being munched.

A quick email to cellman should answer your question and provide the correct answer for others on posting & reading your thread.

[Philistine]

My BMC controller had a "soft start" option which was a jumper cable you could connect or disconnect for activation. When activated it meant that take off was delayed and minimised. It was sold with the BMC motor for that very reason, the seller said that when used it significantly increased the life of the gears.

[John in CR]

Since it takes that long to get to max current, then I'm with Jeremy and it's simply a low Phase current / batter current limit ratio. If you really want to check what's happening with current, start with a reset CA and go to the screen with AMAX. Do progressively longer WOT takeoffs and let off the throttle and see what the max Amps are, resetting between each attempt.

With BlockTime set to 0.1sec, and a phase/battery current limit ratio of 1.3:1 is the only way I could make my SuperV ridable at 30kw peak. Most of the time I still use a 3 speed switch at under 70% for takeoffs, but with care I can take off with the switch on 100%. That's with a battery current limit setting of 425A, which the controller can only hit at 25-30mph on a bike that does 58mph max. If I program the controller below 100A with a similar phase/battery ratio, take-offs are nice and smooth with battery current increasing up to max power.

I wish we had a programmable current ramp up for the throttle like the major manufacturers like Curtis, Sevcon, etc. It works nicely to tune throttle response, and it's ridiculous that's not a feature on our programmable controllers. That kind of "soft start" would get you to max current much quicker, but still be nice and smooth instead of the jerky and dangerous throttle response many of us suffer with.

John

[alfantastic]

Thank you for all of your replies.
The controller operates perfectly for my needs. I ride a lot of slippy, loose gravel trails, and would find huge power dumps dangerous.
The throttle works as smooth as butter, which is a credit to Paul, as I've read that he has tweaked his controller over the years.
I'm gonna get myself a Cycle Analogger, plus a controller programming cable, so I can learn more about the characteristics of the set-up.
I don't need to change the parameters of the controller software, just interested what the settings are.
Then maybe I can post them on here for others to peruse.
Funny thing this electric bike business. The more you play, the more you want to know the finer details