Help With Power Issue
Posted by KillrBeeKilld@reddit | ebikes | View on Reddit | 10 comments
Me and my wife have matching E bikes. They aren’t flashy, but they’re exactly right for us.
Recently, mine started acting up. It would randomly shut down, but I could just hit the power button and it would light back up and keep right going. The new issue I have found is it will speed up and slow down, just slightly, all by itself.
I have swapped batteries with my wife’s bike, but no change.
Is this a problem with the BMS?
I have researched the BMS online and found that Santroll doesn’t make this one, but they make one that’s very similar, MC-MINI-6.
Many moons ago, I worked on electronics, but I’ve never dug into an E bike. Any help would be appreciated.
Most_Tart_5373@reddit
I just got a new battery for my e bike and it doesn't turn on! Can it be the controller? Can someone help??
KillrBeeKilld@reddit (OP)
I won’t make any assumptions. Did you charge it? Does the charger show that it was fully charged? That second question is very important. Batteries require a minimum charge or else they will not hold a charge, at all.
Difficultsleeper@reddit
Always remove the battery from the frame before working on the controller. After removal hold down the display pad power button for 3 seconds or until the display flashes on and off. That will drain any remaining current from the controller.
SadExternal2481@reddit
The silver box is called a controller, the PAS means pedal assist sensor, hidden on the crank / axle area, you might see a small red light on the PAS, it should flash when you pedal forward. Controllers eventually suffer from damp, condensation, over use etc.
KillrBeeKilld@reddit (OP)
Thank you!
Do you think the PAS would cause the varying speed and the random shut downs?
SadExternal2481@reddit
Fault finding takes time and you might need to use a multimeter to check the voltage or see if there is a loose wire, motor tester etc. Battery should be 36v to 42v full
SadExternal2481@reddit
Cutting out might be if the PAS magnet ring is out of alignment / damaged. Shutdowns are usually a controller failure, simply due to age. You could swap the controllers. You might want to test the battery voltage or seek help from a local mechanic.
SadExternal2481@reddit
BMS is just a board inside the battery,
Vivid_Ad_1458@reddit
Check the pins the battery slot into. This design is prone to bad connections and slightly bending the pins usually solves it.
The speed going up and down sounds like you are hitting the speed limit or a bad pas
KillrBeeKilld@reddit (OP)
Thank you for your reply!
The female portion of the battery pens are not accessible unless I disassemble the battery.
I definitely wasn’t hitting a speed limit, I had the pedal assist on the lowest level and we were just cruising down the sidewalk.
What is ‘pas’?