Overheating Controller

[Blunderbuss]

Before I throw my controller in the bin I just wanted to check if anyone else had come across what started to happen today. After being out for about 1 hour my controller cut out due to getting to hot, I use the PAS and only for uphills so it had done 17 mins work over the hour, I checked all the connections and all seemed fine. It cooled down to continue operating after a few mins, but soon heated up again.

I was okay nursing the bike home but after messing around with the PAS levels to see how much quicker it would heat up on the higher settings it got very odd!

It only overheats on PAS 1 (about 90W) on PAS 2 (150W) it gets hot but does not overheat, and on 3,4 or 5 and it just gets warm. As when I use the motor about 85% is on PAS 1 it is next to useless for me.

Any thoughts welcome - or the bin will have it

 

[awol]

I've had a controller overheat in the past because my hub motor was not spinning fast enough for the relevant power level because I was trying it off-road with some slow technical rides, so all I can think of is yours on PAS-1 is not moving your bike fast enough to get rid of the heat into the motor, whereas the higher levels are.
Anyways I never use PAS-1 but only use PAS-2,3&4 so instead of throwing it in the bin, you could always throw it my way.?

 

[Blunderbuss]

Something must have changed as it was fine yesterday, also for a sine wave it is noisier than the square wave it replaced so it could just be a bad one.

 

[Vagos]

Do you keep it in a bag? Maybe slap a heatsink to help it stay cooler...

 

[Blunderbuss]

Yes it is in a bag, when i realised what was happening i took it out of the bag and whilst it cooled down much quicker it heated up just as quickly. A heatsink could work, but i am concerned that is has been working okay up to today - i guess i don't trust it!

 

[BG bicycle]

I did note it’s only an 8 amp rated unit. Never seen a controller rated that low.

Perhaps designed to fail?

If all the wires external be cool to the touch then no short in a cable?

As suggested try on higher PAS setting. Any component problem will soon display sooner unless designed to only run at higher amps. However, expect that to show from day one.

Been out during rain? I soak everything in a water repellent electrical contact spray. Already seen a few monsoon rains and only lost power once when an IEC connector filled up with rain water. The controller cut-out, drained the plug/socket, flipped the breaker off/on and got going again.

The torrential rain wasn’t the actual problem more the gale force wind, although took shelter most part under some trees that didn’t provide adequate cover given the severity of the storm. Live and learn.

 

[Nealh]

Controller rating is often listed as about half of the max rating, though the max rating is shown as well.
Their 12a controller has 6a rating .

 

[Blunderbuss]

BG bicycle - I don't think it is a rain/water issue as it has been fine since i got it (2 months ago) and was okay on Saturday then went "bad" on Sunday - we have had no rain around these parts for weeks.

Nealh - it is connected to to 10AH battery and a 350w Bafang so maybe i need something a little more beefy!

 

[Nealh]

17a is more then plenty for 350w, most likely a fet is failing or a resistor has failed on the pas 1 circuitry.

If the controller has become noisy or resonates noise then failure may occur at some stage.

My Lishui Oxydrive started making a lot of noise and eventually failed, the lvc kept cutting in after a few secs with a pair of fully charged batteries. Though I never thought about checking it for temperature.

 

[Blunderbuss]

Its always been noisy so I shall revert to my old square wave controller and order a replacement, unfortunately with postal costs a return on this one is not worth it. But i shall take it apart and see how they work (sorry awol) and maybe even attempt a repair at board level as a learning project.

On a positive note i had a first "puncture" on my tubeless rear wheel. My LBS built the 350w bafang into a wheel for me and persuaded me to have a tubeless. So after my ride (all offroad) i checked the tyre and pulled out the all to common hawthorn needle and heard the air escaping, so following the instructions given by the LBS and putting the puncture at the bottom it spat out some pink gunge and then stopped leaking after about 5 seconds. The needle could have been in the tyre for 10 yards or 20 miles, but in my experience i would have had a flat quickly and need to repair it. I had tried the tyres that are supposed to offer protection and those bands that are supposed be "almost" puncture proof - but nothing had stopped the hawthorn!!