controller problem?

[stompatompa]

Hey! I bought a s12s controller from bms battery. When I run it with no load everything is super smooth but when I ride it there's a problem. If I accelerate hard or try to go steep uphill it just cuts power. Almost as if the battery can't handle the amp-draw but when I restart everything is fine again.
The controller is 48 or 36v 30a max and the battery is one of the regular 48v dolphin batteries. I've also tried with a36v battery and its the same problem.

Thankful for any suggestions!

 

[motomech]

The controller is trying to draw more current than the battery management will allow.
The max. continuous discharge rate for the Budget Li-Ion batteries is 18 Amps.

 

[stompatompa]

Thanx for the quick reply! Is there a way to limit the controller? (Some kind of reversed shunt mod maybe) I've been running this dolphin pack without problems with a bbs02 750w so it should be able to take 25A right?

 

[bobsyleck]

Just a thought but have you considered swapping-out the BMS on the Battery Pack? I have to say I'm fairly novice at this and am not familiar with your Battery Pack but I have successfully built my own Lith-ion Battery Pack in the past with good results.
There are quite a few choices on eBay i.e. http://www.ebay.co.uk/itm/151987351304?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT this one has a 25a discharge rate - but I'm guessing you need to be aware of your batteries 'C' Rating and capabilites.
*and when choosing your BMS Board be aware that some are meant for Lithium-Ion and others for Lithium Poly (the two types have different Charge and Discharge tolerances).

 

[Eskimo]

I had a weird controller problem two days ago.
Suddenly middle of a ride controller died, very instantly. It did not let any power through either way, totally dead. I pedalled my velomobile 15 miles home.
Next morning i decided to give it one more try, and it worked again! WTF? I already ordered a new controller.
It seems it somehow shut itself down for some reason, there is some protection circuits as far as i understand. Voltage was 100% ok. It was not voltage protection.
Any suggestions?
Controller is KT36ZWSRM-XFF02
Battery max voltage when full is 54,4V

 

[motomech]

Controller is KT36ZWSRM-XFF02

That tells us nothing-copy and paste the specs.
There may be a thermal protection circuit. Does it get warm, hot?
Carry a multi-meter on the next ride and if it shuts down, ck the Voltage @ the main power wires @ the controller.

 

[Eskimo]

Controller is KT36ZWSRM-XFF02

That tells us nothing-copy and paste the specs.
There may be a thermal protection circuit. Does it get warm, hot?
Carry a multi-meter on the next ride and if it shuts down, ck the Voltage @ the main power wires @ the controller.

It does get hot at times. I have watt meter on line and it showed ok voltage.
What it has done couple of times since new is that it shuts down suddenly and randomly, but restarts fine when you push the button.
This time it did not restart. Power delivery to the controller is 100% ok. Possible fault lies somewhere after that, in the controller itself or the wires between the controller and LCD unit.
I just can not understand how possible contact break between the controller and the LCD unit can shut it down, maybe it can.
Brake lever switch failure can shut down the motor example, but LCD power stays on. In this case LCD dies completely.
What i noticed this time was that there was no power delivery from the motor to the watt meter when i pedalled.
Usually DD motor delivers some power when you pedal which lights up the watt meter and gives readings.
So we may have a contact break between the controller and the motor, which somehow shuts LCD down too. Dunno.