Cytronex Genesis Day One problem

[brueh]

Hi All,

I have not been here for a while and immediately got stuck reading lots of interesting posts...

Now I have a problem with my Cytronex Genesis Day One. Actually it is not really a cytronex any more since the motor is a SWXK5 250W, the controller is new (the 250W from BMS battery) and I use a thumb throttle now. The reason is that the Cytronex system shorted one day and I did not have the money to have it replaced by Cytronex.
Recently the system stopped working properly again. When I plug the battery in the motor works for about 30s and then stops doing anything. The light and the LEDs on the thumb throttle still work. When I unplug the battery and plug it in again it works for a certain amount of time, depending on how long I had it unplugged. If it was unplugged for 5s the motor works for about 10s, when unplugged for 10s the motor works about 17s and when unplugged for 20s the motor works about 30s. This sounds like some capacitance is building up opposite voltage but I do not know enough about the system to have a clue what is going on.
I had the bike checked by the friendly people from the electric transport shop in Cambridge and they say that all the components re working fine when plugging a battery directly in the controller. So they recon it is something with the battery or battery connection. I bought a new battery from cytronex and have the same problem.

Any suggestions would be very welcome as this bike has been broken for most of its life but is a lot of fun to ride when it is working.

Many thanks in advance!
Bruno

 

[flecc]

The consistency of that operating time after various switching off periods seems to make a battery connection problem unlikely, but it does have the characteristics of a battery failing under load as ETS think. However, I doubt that's the case since it isn't consistent with the NiMh cells that the Cytronex battery uses, also it sounds as though the fault is there even when the motor isn't under load but just being spun*, and you've tried two batteries.

*Is that so?

It can't be a controller or motor component failing with temperature rise if what ETS say is right, that it works with a battery coupled in directly to the controller, by which I assume they mean not a Cytronex battery.

So if what ETS say is true, that points to the Cytronex battery coupling plug/wiring, despite what I said at the outset. I'm not familiar with that battery plug-on connector that Cytronex use, but I'd say first open it up if you can and check it's connections thoroughly. Another approach is to connect a meter to the supply cable at the entry into the controller and check if the supply fails at the point when the motor cuts out with front wheel lifted off the ground. That will prove or disprove a battery connection problem.

 

[brueh]

Thanks for your reply flecc!

...also it sounds as though the fault is there even when the motor isn't under load but just being spun*, and you've tried two batteries.
*Is that so?

Yes it is even there when I do not use the motor at all, if I plug in the battery and wait for some time it does not work at all - so I have a window of 30s where the bike works as normal and afterwards the motor does not do anything.

It can't be a controller or motor component failing with temperature rise if what ETS say is right, that it works with a battery coupled in directly to the controller, by which I assume they mean not a Cytronex battery.

That is right, it was not a cytronex battery - I do not know however if they tested for more than 30s.

So if what ETS say is true, that points to the Cytronex battery coupling plug/wiring, despite what I said at the outset. I'm not familiar with that battery plug-on connector that Cytronex use, but I'd say first open it up if you can and check it's connections thoroughly.

I did that before when the motor did not work at all - cleaned the pins (BTW the ETS people say that they are pretty thin for the amount of current they have to handle) and afterwards I ended up in the situation described. Further cleaning or fiddeling around with the plug did not change the situation. However I can hear a noise that sounds like a tiny spark when connecting the battery - suggesting that there is some current floating. Are there any capacitors charged in the controller when connecting?

Another approach is to connect a meter to the supply cable at the entry into the controller and check if the supply fails at the point when the motor cuts out with front wheel lifted off the ground. That will prove or disprove a battery connection problem.

Yes I will try that tomorrow. Thank you!

 

[jhruk]

Have you checked that the Cytronex batteries are charging properly? Might be worth checking the charger and its connectors.

 

[hech]

Hey Bruno you seem to have replaced everything but the rider, have you yourself been checked?
My battery connector also sparks when plugged into the controller, sometimes quite feircely even though there is no load on the circuit except for the capacitors filling up in the controller??? So I too want to know what the devil these things are doing in there, and why? If d8vey were still with us he would know.

 

[flecc]

My battery connector also sparks when plugged into the controller, sometimes quite feircely even though there is no load on the circuit except for the capacitors filling up in the controller??? So I too want to know what the devil these things are doing in there, and why? If d8vey were still with us he would know.

It's surge protection, absorbing connection current to avoid controller component shock. They can also have the function of smoothing the motor phase demands on the battery.
.

 

[hech]

thanks Flecc. Its just that the sparking on connection seems way too intense for an unloaded circuit-hot enough to part melt a connector even!

 

[flecc]

Must be fairly high capacitance then, powerful setup? Trouble is a path resistance to damp the surge isn't practical, given the current demands. Many proprietary e-bikes have a keyswitch in circuit between the battery and controller as in this eZee schematic, so connection shocks are not seen