Controller getting really hot…

[Danimal160]

Hey,
New here and new to e-bikes completely, I brought a custom made e-bike had a issue juddering low end motor mad like a grinding noise too, spoke to a e-bike specialist who suggested I install a new controller. I’ve done so but now the controller gets crazy hot so I have stopped using the bike for now. The bike has a 3000w 60-72v motor and a 60v 45Ah battery both controllers are Chinese first one says 50v/56v/72v this is the one with the juddering issue and the second Chinese controller says 1500w this one had the over heating issue. Like I said I have very little knowledge about anything to do with this but I did change the controller over and have a volt meter, soldering iron and bits.

No clue if it’s relevant but bike is a little fold up bike 14inch wheels with a box fabricated to the frame for battery and the controller!

Thanks

 

[calab]

Airflow is something I'd look at first, generally you dont want the controller inside any bag. It requires airflow to help cool things down.

Buy a more powerful controller 60v 50a if you want 3kw, be sure the controller has airflow.

More advanced users could look inside the controller and see if the fet heatsinks are beefy enough and if the mini bolts (the bolts you see on the side of the controller) are tight to help facilitate heat transfer from the fet backing plate to the aluminum casing of the controller. I noticed the white grease stuff, like a transfer of heat product used for pc cpu's. It might be the case the worker forgot to put some on, forgot to tighten the fet backing plate bolts.

I had one controller where I took the fet bolts off the housing and had a metal spacer fall onto cont pcb. It was quite the finger yoga to get it secured again. I then sometimes will use a pc of paper, some other non conductive material to fit on the under side of the controller. I seen it done on my Lyen, it was actually an 18fet.

 

[DingusMcGee]

If the motor’s Hall transistors are down low and subject to water and severe dampness/wetting, the controller and motor will run warm to hot with the motor chattering and not producing much power.

To fix, remove the opposite motor side cover from the output shaft, the drain water, leave cover off overnight to dry out and when assembling apply red silicone RTV sealant to the joint rims of the cover.

Some motors are not very waterproof (Cyclone 6k) and if the motor mount orientation puts the Halls at the lowest position, the slightest bit of internal water will short circuit the Hall signals sometimes intermittently.

 

[slaphappygamer]

Or perhaps the motor hall sensors are already bad. Since a similar condition exists with the old controller. I found this video useful in explaining how to test.

 

[MarkJohnston]

My experience with chinese controllers is awful. Whatever you do don't ever touch any of the wires together. MAke sure you tape all connectors you aren't using.

I second the air flow idea. You need to get that thing in the open air.