The controller, 25A or 35A ?

[Bonvin]

Hi

It's safe to run the Ebike.ca 25A controller at 25A (36V or 48V)

I will burn it in a week

Or, it is better to use the Cycle Analyst to limit at 25A the 35A controller

Is the 35A controller more efficient at 25A than the smaller one

The "controller resistance" is lower in the 35A controller

Is the Ebike.ca controllers ( 25A and 35A) have the battery and phase limiting implemented


Yes,i have a lot to learn

Thanks in advance for your help.

Gillis

 

[dogman dan]

If you only want 25 amps just get the 25 amp controller. Run it at 48v and you will have plenty of power for hills and such.

 

[Joey]

I would trust the current limits on the controllers at ebikes.ca. If you need 25A then a 25A controller will supply that amount day in and day out with no problems. The only caveat is that you mount the controller where it can get some air flow. Hiding it in a pannier or trunk bag is asking for trouble.

With regard to utilizing the Cycle Analyst to limit the current on a controller, I have a cautionary tale to report. Does your battery have a BMS with current limit shutdown? If so, you should not use a controller rated at more max current than the battery current limit. I had a problem trying to use a 20A rated LiMn battery pack with a Crystalyte 35A Analog controller. I used a Cycle Analyst to try to limit the controller current to 20A but it really didn't work very well. The problem was the Cycle Analyst was employing a separate control loop on top of the Crystalyte internal control loop. There was a noticeable control lag in this compound control loop that resulted in the following state of affairs.

The 20A CA limit worked decently under steady state conditions, that is, while traveling on level ground at constant speed. However, slight changes in terrain slope or speed would cause the control loop to swing between overshoot and undershoot conditions. I tried adjusting the related current control loop parameters in the CA over a pretty wide range and still was not completely satisfied with the response. There was just too much lag when the CA interacted with the Crystalyte controller in trying to maintain the current limit.

However, a more serious problem occurred when applying moderate throttle from a standstill, the current draw of the controller from the battery would instantaneously exceed the 20A current threshold causing the battery BMS to trip and shutdown. The CA control loop would overshoot the target threshold due to control lag so that even though it was trying to do the right thing, it just could not do the job fast enough to avoid the BMS trip. I actually had to reduce the current limit to about 12A to avoid tripping the 20A BMS when accelerating from a standstill. That left me with an unsatisfying amount of available steady-state current.

I should restate that my only experience has been with a Crystalyte controller. I have not used a CA to set the current limit on an Infineon controller. I suspect it will exhibit the same problem as occurred with the Crystalyte but I don't know for sure. My sure-fire solution has been to never use a controller whose current limit exceeds that of the battery BMS. If your battery BMS is good for 35A and you have a 35A controller, than the CA will do a decent job of limiting current to something lower like perhaps 25A and the BMS will be in no danger of tripping since now matter how much the CA overshoots the current estimate, the controller will never put out more current than its own internal limit.

Joey

 

[dogman dan]

I agree, if your battery is going to last better with the 25 amp controller get the 25. The CA current limiting is not a better solution than the right size controller. I run my 22 amp Ebikekit infineons pretty hard, and have no problems with them since i mount them in the air flow.

 

[wineboyrider]

Joey and Dogman are right. You should factor in what battery you are using first and then decide if your batteries can handle the current draw and remember that higher amperage means less battery life. In other words you need a batteries that can handle your controller.
Trust us we are all from New Mexico 8) 8) 8) 8)

 

[Bonvin]

Hi everybody.

First of all tanks for your reply.

Thank you for sharing your experience with me.

If i read you correctly the bigger is not necessarily better.

I will probably go for the smal is beautiful and buy the 25A controller.

Anyway i dont want to go very fast i want to go far a way. It will be good to keep the power to the minimum.

It dont take long to pass through a 20A/H !


Gillis

 

[mwkeefer]

If I'm not mistaken the 25A controller is made with the P75N75& FETS same as in dogmans Infineon controllers... the 35A model is outfit with IRFB4110 FETs...

Given the choice, I would take the IRFB4110 outfitted model... check with justin first to be sure the fets are the better ones...

If the controller you order isn't a EB7XX series then you can also use a USB to TTL adapter to flash program the settings to exactly the right level for your battery, throttle, bms, motor and riding style.

-Mike

 

[Demosthenes]

The 25amp from Ebikes.ca uses IRLB4030 fets. Good up to 100V

Yeah, the CA needs time to react to an overcurrent situation. I was using a 20amp rated battery with a 35amp controller and the current limited to 15. If I jammed the throttle to hard (Very easy to do) the BMS would trip before the CA could limit and the bike would cutout until I leaned back and hit the switch on the battery off and on again. So just go with the 25amp controller.

 

[Bonvin]

Hi Mike.

I have the confirmation from Justin. Both comtrollers the 25A and the 40A are build around the 4110 mosfets !

From his point of view the 25A controller can easily drive the NC2805 hub.

I cant tel you if it's the EB7XX series ?

If i read you correctly these controllers can be reprogrammed ? Ho, it's new for me !

Is this means that we can change the battery current limiting ?

For example we can reprogram the 40A controler to work like the 25A controller ?

Or can we change the phase current limiting, in oder word can we change the output current limiting to the motor ?

For doing it, do we need a special programmer or this can be done with a PC and the needed software ?


Hum it is midnight and i have an English headache. :lol: :lol:

Thanks in advance Mike for your answer.

 

[wineboyrider]

I have 2 programmable controllers now, but haven't had a chance to figure out how to program them. It's better to optimize them to what motor and battery you are using. I have two hub motors one that is a geared hub motor that uses very little ah per mile or watts per mile for distance and a larger direct drive 9x7 (2807 at ebikes.ca) for speed. I want to optimize the controllers for each motor eventually so can have a bike that can go far on one charge and a bike that can go faster.

 

[Bonvin]

The 25amp from Ebikes.ca uses IRLB4030 fets. Good up to 100V

Yeah, the CA needs time to react to an overcurrent situation. I was using a 20amp rated battery with a 35amp controller and the current limited to 15. If I jammed the throttle to hard (Very easy to do) the BMS would trip before the CA could limit and the bike would cutout until I leaned back and hit the switch on the battery off and on again. So just go with the 25amp controller.

Yes you have the same problemes than Joe ! The BMS is faster than the CA at detecting an overcurrent. I am not shure how the CA is limitting the current. Probably by lowering the throttle? Hum, from what i can read it's not the way to go ! It would be funny to be able to reprogram the converter output current limiting !

 

[Demosthenes]

I am not shure how the CA is limitting the current. Probably by lowering the throttle? Hum, from what i can read it's not the way to go !

Nail on the head. It overrides the throttle signal with it's own.

 

[heathyoung]

Designing a PI loop is hard to get right. Tuning it is a new hell in itself.

There is no control over the derivitive in the CA so I'm assuming that its PI rather than PID control. I'm in the midst of writing some PID code at the moment and its giving me the screaming bejeebus.

 

[dontsendbubbamail]

Designing a PI loop is hard to get right. Tuning it is a new hell in itself.

There is no control over the derivitive in the CA so I'm assuming that its PI rather than PID control. I'm in the midst of writing some PID code at the moment and its giving me the screaming bejeebus.

Back when I was mucking about with the RC controllers I played with some PID code that I got off the net for the Arduino. In my case D was not needed in order to control the battery current.

Bubba