Daymak Max S 48v 500W fails under load. When idle, all functions test ok - from controller forward and rearward into hub.

[ogopogo]

The first 20 - 30 minutes of a ride are ok then, power drops, surges, drops surges. This will continue for several minutes then, power to wheel is lost. The display will show a code 03 at this final point. After sitting idle for a period it will run again with no error code (the longer I sit, the longer it will run on the next try). This is a new bike - 32 Kilometers at the beginning of this. My take is a weak MOSFET in the controller and a replacement is slowly on its way. I wonder though, can the hub display such a failure?

 

[neptronix]

Do you have a realtime display of the voltage/wattage of your battery? this sounds a lot like a saggy battery ( too small for the load, damaged, or old ) cutting out early.

 

[ogopogo]

I have 2 new batteries, one Daymak and one custom built for me. Both exhibit the same problem. You could be correct and both are bad but the odds are ..? I will connect a meter to test that I can ride with. I have an rc meter which will show all the necessaries

just found meter and pulled specs from online - up to 60v and 130A - will insert and test when it stops raining.

 

[neptronix]

Low odds on it being the battery then.
Is that controller smoking hot when it cuts out? an interesting test would be to ride it until it cuts out, give it about 5 min, and try again.

 

[neptronix]

Turnigy 180A Watt Meter and Power Analyzer

^-- 60v limit, accurate enough, and cheap

 

[ogopogo]

no smoke - see my edit above to show G.T.Power Rc wattmeter 130A 60V. As stated, it returns to operational after brief rest - the longer it rests, the longer the next run but never over that 20-30 min.

 

[ogopogo]

also found my Watt's Up (retired) meter, good to 100A 60V. I should be set.

 

[neptronix]

It doesn't have to smoke to be overheated!
How hot is that controller at the end of the ride, too hot to touch?

 

[ogopogo]

no, I agree. these folks enclose the controller in a tiny plastic box - no chance of conduction to air or frame. I have removed the Daymak battery and installed the controller to the metal plate and in free air flow. As soon as the rain stops, I will ride with the watt meter and a remote temp sensor from my distilling days. That should give some good indicators.

 

[ogopogo]

here it is
50.18v min
20.25A peak
1038.1W peak
45.7 C controller case temp

so, taint battery sag or controller temp
one thing does concern me - 20.25 A peak on a 20A max controller but I doubt that's the fault I'm looking for

 

[neptronix]

That's not really a fault.
45c is a bit on the hot side but not critically hot, too hot is, you can't hold your hand on it for more than 5 seconds.

How many amp hours is your battery?
How many volts does it sag when you hit the throttle all the way?

 

[ogopogo]

sag is in the second # posted above - 53v down to 50.18v - no issue
Daymak batt is 10AH
custom is 15AH

just replaced controller with a new one - same problem. I think I need to pull the hub ??

 

[fechter]

Not much left at this point. The sag and peak current measurements look OK.
Do you know if the controller is sensorless or uses hall sensors?

 

[ogopogo]

hall sensors which test ok on stand

 

[fechter]

Any idea what Error 03 is? I searched and did not find a complete listing. It's possible one of the hall sensor signals fails when the motor warms up.

 

[ogopogo]

03, to the best of my knowledge, is a communication error to the hub. That cetainly would apply to a defective hall effect sensor. I hope to be pulling the wheel tomorrow and will advise what I find.

 

[neptronix]

Worst case scenario you can run a sensorless controller.

 

[ogopogo]

Before I open the hub, I want to see if Daymak will honour their warranty. They don't answer their phone, I haven't received the controller they said they would send. Reply to my web contact was an automated response so I'm not sure how this is going to go. My test this afternoon was to drive until the pulsing started then test into the hub. It only took a few minutes but I was able to see all three hall sensors indicate and phase continuity check. I just don't know what else I can test without a physical inspection. A bad solder joint can pass 5v and minimal current but not 48v 15A so that should be my next move.

 

[ogopogo]

of note, the cable to the hub was quite warm

 

[neptronix]

Well lucky for you, you have zero help from a prebuilt manufacturer, but you also have an account on the most active ebike DIY forum on the planet.

If i were in your shoes i would be running a high quality programmable controller that's well documented and ditch their controller and electronics entirely so that i know i have something reliable.

of note, the cable to the hub was quite warm

This may be typical for the hubmotor and isn't necessarily a sign of a fault, a lot of manufacturers use undersized wires to save money.

What would be really telling is if you disconnect the phase cables and one is significantly hotter than the other, this might mean that you have an intermittent short in the motor's wiring ( this would mean it's missing enamel/is corroded/etc )

 

[ogopogo]

Got it. Pathetic lead layout in motor pushing FET sensor out of its slot. Shute-load of glue making it worse. Test ride completed.

 

[fechter]

So did that fix the problem?