intermittent loss of power

[morphix]

I'm having this intermittent loss of power problem on my eMezzo (Q100 motor and KU63 controller)...

The power does not always start from a standing start unless I repeatedly flick the throttle several times and/or start pedalling then engage the throttle (I have no PAS fitted, only throttle)... and when it does start, it cuts out after a while (usually when the throttle is at full power, although that could be a speed restriction in the controller, as this bike FLIES and I believe is doing well over 15.5mph on throttle). Flicking the throttle a few times again, restores the power for a minute or so, then it cuts out again. So I'm thinking this is probably normal behaviour, and a speed restriction? But the standing start problem and unresponsive throttle when just pedalling (very slow in high gear) is puzzling.

I've checked all the wiring connections, and apart from a faulty throttle or lose wire in the throttle somewhere (which I haven't ruled out) I can't think what else it could be. Any ideas?

I haven't yet got round to fitting a PAS sensor, so it will be interesting to see if that has the same problem, which may isolate the problem to the throttle.

Since I have no easy way to enable/disable PAS while riding (still haven't tried fitting my Speedict, and not optimistic it will work, based on other HTC handset owners comments) I'm tempted to just buy one of the new S-series controllers from BMS Battery which come with the familiar LCD console I'm used to from my first e-bike build.. then I won't need the Speedict.

I'm also tempted to replace the Q100 motor on my eMezzo as it just seems far too powerful, and too big, for this little 16" bike. I haven't checked properly yet, but I believe it compromises the fold too. It certainly adds unnecessary carry weight to the bike, and my main objective on this build was a super-light build.

I will conduct further tests and report back on these issues shortly ;-)

 

[Deleted member 4366]

Looks like you've got the only problem I was never able to solve. I built a 2WD with 328 rpm Q100s. I had quite a bit of trouble getting the motors to start when I was building it, but once it was on the road, it seemed OK. Then I over-heated both controllers going up a very long hill, and everything became very intermittent afterwards. Assuming that I'd damaged something I bought two new controllers, but still they would hardly start. I spent ages on the problem, and found that the motors always started with the KU93 controller, and each time I reconnected the KU63, they started first time, and worked perfectly til I let go of the throttle, then it was back to starting about one in seven times.

I gave up on the problem, and left the wheels in Saneagle's garage. Some time later, he broke too many spokes on his 2WD rear Q128,so he tried the Q100, which has worked perfectly ever since with a KU65 controller.

I think that the problem is something to do with the automatic phase/hall sequence detection, which the controller can't figure out for some reason. I think your idea of trying the S06S, is what I'd do.

 

[cwah]

or also get another controller from another brand?
http://www.conhismotor.com/ProductShow.asp?id=103

 

[morphix]

or also get another controller from another brand?
http://www.conhismotor.com/ProductShow.asp?id=103

Thanks for the suggestion, but I think the BMS LCD one has swayed me, I've been waiting for AGES for them to start stocking the LCD controllers and constantly nagging them to.. finally they have! This makes for a much more functional e-bike experience IMO based on my first build.. you can fine tune how you use the bike and get a good balance between power and fitness, plus see how much power you're using and how much is left..

 

[morphix]

Looks like you've got the only problem I was never able to solve. I built a 2WD with 328 rpm Q100s. I had quite a bit of trouble getting the motors to start when I was building it, but once it was on the road, it seemed OK. Then I over-heated both controllers going up a very long hill, and everything became very intermittent afterwards. Assuming that I'd damaged something I bought two new controllers, but still they would hardly start. I spent ages on the problem, and found that the motors always started with the KU93 controller, and each time I reconnected the KU63, they started first time, and worked perfectly til I let go of the throttle, then it was back to starting about one in seven times.

I gave up on the problem, and left the wheels in Saneagle's garage. Some time later, he broke too many spokes on his 2WD rear Q128,so he tried the Q100, which has worked perfectly ever since with a KU65 controller.

I think that the problem is something to do with the automatic phase/hall sequence detection, which the controller can't figure out for some reason. I think your idea of trying the S06S, is what I'd do.

One thing I forgot to mention..which may confirm your experience here.. I've noticed that my KU63 controller is getting noticeable hot to the touch after a short ride at full power (which seems like 20mph, but i have no way of checking unless I use my mobile phone's sat nav).. so it could well be that the 350W Q100 is just too much for current this low-end controller? Maybe the controller is "switching-off" internally to protect itself from burning out?

 

[Deleted member 4366]

High speed doesn't warm up a controller very much, but low speed at high throttle will. The faster you go, the more back EMF your motor makes, which cuts down the current to the motor.If you have the controller in a bag, it'll get quite warm, but they can go up to too hot to touch before problems start. There's a thermistor in the KU63 that shuts it down if it gets too hot. If you take the controller out of the bag, it'll hardly get warm, so you can easily test if over-heating is your problem.

 

[morphix]

High speed doesn't warm up a controller very much, but low speed at high throttle will. The faster you go, the more back EMF your motor makes, which cuts down the current to the motor.If you have the controller in a bag, it'll get quite warm, but they can go up to too hot to touch before problems start. There's a thermistor in the KU63 that shuts it down if it gets too hot. If you take the controller out of the bag, it'll hardly get warm, so you can easily test if over-heating is your problem.

Good idea, I'll run some tests with it on a ramp and the controller out.