So I recently bought a 'Motor Brushless Controller for 36V/48V 350W' from Ebay for my e-bike and then when I contacted the seller about the 'Current' because I didn't know what it meant, and he told me:

"That means the current data is not a fixed value, but fluctuating. It will up to 18A or down to 16A." (still waiting for his response)

This is the item details:


  • Rated Voltage: 36V/48V
  • Rated power: 350 watts
  • Current: 17±1A

Item on Ebay: - http://www.ebay.com/itm/361462855827?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

So I just wanna ask a simple question, will it work on my e-bike? I have:

  • 48V 13A Battery
  • 250W Motor Controller (wanted to switch to 350W)
  • 250W 8Fun rear wheel hub motor
  • \$\begingroup\$ much better than your last question from today! \$\endgroup\$ Commented Apr 14, 2017 at 11:51

1 Answer 1


17A+/-1 is not valid without conditions.

This may refer to the surge current for starting a motor which can take 5~8x the Watt/Volt ratio but it affect internal temp rise affect by initial conditions and ambient T.

Batteries are rated in storage time in Amp-hours [Ah] and Cranking Amps CA so 13A must be Ah....

Hopefully it represents a current limited switch sensed and controlled by PWM. with a threshold tolerance (if true) 17A compared to your motor 250w/50V =5A is roughly 17/5A= 3.6x rated load should give good acceleration.

15Ah implies you can go full load 5A for 3h with no acceleration or less with accel.

FWIW, Ebay specs are almost non-existent and not worthy of trust, but it may be ok for you. Ask for an e-file of user manual.

  • \$\begingroup\$ Thank you so much for the answer, I think it answered most of what I needed to know :) Also why would I need an e-file of user manual? \$\endgroup\$
    – user135614
    Commented Jan 11, 2017 at 14:47

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