Magic Pie cutting out under load

[real]

I'm not great with computers and electrics, but I have a problem with my MP and would like to know how or if someone can guide me to solving this problem. Basically it's like this, fan in charger does not turn on, light is green, turn key on lift front wheel off ground turn throttle wheel turns nicely add a bit of resistance and throttle lights go off and wheel stops turning. turn key to off then on and throttle lights back on. lots of torque if wheel is jammed from turning, but as soon as it starts to turn with ever so slight resistance power shuts off. My email.  Rjlaurin@shaw.ca.    604  809. 7325.  Real Laurin.  Purchased mp two years or so ago 48. 1000 w  very little use. Please advice. Thanks

[Bikemad]

Hi andto the forum Real.

It sounds to me as if you may have a problem with either the battery, the key switch or the main power connector on the battery.

If you have a voltmeter it would be useful to know what the battery voltage is reading immediately before the power cuts out.

If the battery was purchased at the same time as the motor, I suspect that it will be the older Lithium Manganese type, and one or more of the cells is probably faulty. This would cause the BMS to shut off the power if the voltage of any single group of cells falls too low under load.

Alan
 

[real]

Thank you for your reply.I'm new to this forum and this type of available information. I've now read a lot of discussion about MP and there sure is a ton of very good solutions and test procedures that can be performed. I thought I should start off by draining the battery completely so I safely secured the bike off the ground, read the voltage at battery terminal, 51 v , throttle open full, cruise control engaged, and the front wheel fired up. After about 30 mins. I shut it off and read the voltage at battery, now 49 v. Before turning it on again I disconnected the power connector near the MP unit and inserted two small electrical wires in each of the connectors and pushed the connectors back together. This way I could measure the volts under load , using my rubber pad brakes without the re gen kicking in. Pad brakes applied I got the reading down to 35 v without things turning off .I don't really know why it's working now but tomorrow may be different. The fan on the charger also now works. My next step is to check the voltage of the separate battery groups under load and see if some cells are dead or some are not getting charged due to others charging faster and shutting down the unit. If so I will then purchase a timing device for the charger. I'll let you know what I find. Cheers.   Real