Intermittent power loss

[erdurbin]

The only other thing I can think of is the wire awg is too small or over too long of a distance.

What awg of wire are you using and how many feet of wire is between your batteries and the controller?
Can you post a pic of your battery pack?

[OneEye]

Track the voltage across each battery while you are under load and when the cutoff is occuring.  You can narrow down whether it is a controller problem (the sensed voltage for low-voltage cutoff is wrong) or a battery problem (they can't keep up with the power demand).  I'd bet it is one of these two issues.

[commuter]

thank you both.
The controller to battery is the set that comes with the front hob motor kit.  And I will do my best to test voltages under load.  The controller did not cut out for the first day and a half under same load.  I think my battery charger is not working and I am running on discharged batteries.  I am ordering a charger and will see then what happens.

[myelectricbike]

  The batteries need to be conditioned.  Charged and used a few times before there full potential is realised...  ...The first run will only give you about 10km the subsequent runs may get as high as 30km.

Fully conditioning new cells (assuming all cells in your battery are new) may take upwards of thirty cycles. You can use a data logger to automate measurement of both the battery pack and the charger during the charge cycle to determine which one if either is falling down on the job.

[David Merrill]

Dear Commuter;

I just bought two more motors to replace my old style one. The old one worked most excellently and my two new controllers have this exact problem you describe. I am technically able and will fix it.

I have a Fluke 89 that Records and the cutoff happens at 31.2 Volts from the batteries. I ran them down to where the loaded motor became intermittent and loaded them individually - they are all good. They go from 6.5V to 5.2V under about 1.8 Ohms. That explains it and I am supposing that with newer Lithium and Nickel Hydride batteries - especially the sensitivity of the A1-2-3 DuWalt packs, that the LVC is for protecting low voltage from ruining the batteries. I have six Cyclon (Hawker) batteries military spec to be good for at least 300 full discharges and relatively cheap to replace so the intermittent power, especially in traffic is completely unsatisfactory.

Without opening the controller, I am picturing a comparator with a reference voltage of 31.2 Volts and I want to turn that down to about 25V, maybe completely disable it - no Low Voltage Cutoff at all.

Can I get some instructions first?


Regards,

David Merrill.

[David Merrill]

thanks! I will read there awhile first.

http://goldenmotor.com/SMF/index.php?topic=198.15



Regards,

David Merrill.