electricrider.com Xlyte brushless controller troubleshooting

[NeilP]

Just went round to a mates house today, as he has just got his first bike built. He bought a kit of parts from Elecrtic rider, and a pack of LiFePO4 from Jim at Headway Headquarters
Not sure exactly which motor apart from it is a rear sensorless HS/HT series Xlyte, with a 72 volt 40 amp sensorless Xlyte controller
Pack is 48 Headway cells, half int he frame and half in rear mounted box, with the BMS and the controller.

He does not yet have the Xlyte "CA' but wanted to know how fast it was going.

We went out for a ride around the block, and got just on the 40 mph out of it. Came home and all was fine. He was a little worried about how warm the controller was getting, so he opened the lid on the rear box to show me and also flick the off switch on the back of the controller.

As he lifted the controller out, the was a feint sound of a spark...nothing big like the spark when you connect the batteries to a controller without a pre charge resistor, just a very quiet 'tick' that had the wind been blowing strongly you probably would not have heard it.

The only connection on the controller that were made were the throttle, battery, and phase wires to motor.

That leaves 4 plugs not connected: Brake cut off, cruise, Xlyte CA and and a two pin plug with a jumper. Was assuming the two pin with jumper was possibly a regen brake enable.but since this is a sensorless controller , this could well be a motor adjustment plug..not sure what to do with that or how it works.
All these leads are all fitted with the small black multi pin connectors.

Anyway..after this minor spark, there is now no response from the throttle.

The LED on the controller is on, but nothing happens when throttle is turned.

I took one end of the controller off, and checked for loose solder, swarf etc creating a short inside the board, but found nothing, removed the board and all at least looks OK ..nothing obviously burnt.

He did not have a multi meter that worked, so we could nto check any more then, so I took controller home and have verified that there is 5 volts out of the throttle plug, along with the battery voltage on another pin ( 4 pin throttle)

All we can see or think of that may have caused the spark, is one of the terminal on one of the unused plugs coming briefly in to contact with a metal part of bike/battery box/controller

Did wonder about the BMS tripping...but if that had happened, then I would not imagine the controller power LED would light up at all...but maybe I am wrong...does a Headway BMS cut all power when there is a short condition...or just cut main power and leave a low current battery voltage still up and running?

Anyone any ideas...what to try next?

Since we are in UK and it would mean sending the controller back to Canada, want to try all we can this end first.

 

[JimmieD]

Hi Neil,

I can at least comment on the BMS, the BMS will cut out if a short is detected:
4. Function of short circuit protection: once battery group's output port appears the condition of short circuit, it cuts off to ensure battery group not to be damaged because of short circuit.

I would start working at tracing the problem by starting with checking the Vout of the battery, but it does sound as if the controller is accepting voltage since the power LED is on.

Hopefully others will see this soon and be able to provide their experience and problem solving solutions for you and Mark on the controller.

 

[NeilP]

Hi Jim,
thanks
I was going to check with you next , but wanted to wait and speak to Mark first

Mark did have a DVM, but it was dead...no voltage readouts...so I took the controller home to check it out.

Was wondering about the BMS, but since the LEd was powering up discounted that.

All I can think of that shorted would have been one of the pins on the black multi-pin plugs..the most likely would have been a battery voltage pin on either the cruise control or the , Xlyte APM plug.

Mark could not remember...what cells has he got there? the 8 10 or 12 Ah ones?...what is the Max current of the BMS set to?

Cheers

Neil

 

[JimmieD]

Mark has the 38120SE 10Ah cells, 2P24S configuration, the BMS is 50A~70A continuous with an over current protection of 110A~135A (100A load) with 50A charging capabilities.

 

[NeilP]

Ok, thanks

I can at least lend him a controller and now I know what I can limit it too ..even if it means I have to fit him some hall sensors to his motor.

Oh BTW..nice pack and charger

 

[JimmieD]

Thank-you, it was a fun one to build!

 

[NeilP]

Will send pics when running again. Am trying to get Mark to move the rear pack lower and close in towards the seat post. I reckon he has it too far back at the moment...makes the bike a bit rear heavy with a high C of G.

 

[NeilP]

Update.

Went and had another look this morning, so check and see if the throttle was giving an output, and to check pack output to see if BMS had tripped.

Solid 79 volts out of the pack, ...but hey wait that is weird...on measuring voltages...the controller case is at battery voltage with respect to the battery connection negative.

That would explain where the spark came from when moving the live controller in the box. The controller was sitting on board, with foam blocks either side as a temporary mount, in a metal box.
As the controller was moved...we heard the spark...and thought it came from the corner of the controller case ( one of the end plate screws) and the metal box...but that did not make sense, so we assumed that one of the un connected plug live pins must have touched something.

Have looked inside and cant see any loose solder or evidence of the traces on the bottom of the board touching the case..so not sure now.

How else could the case become live? ```````via the heat sink bar and one of the FETs?