timchump

Hi, I’ve just installed a s886 controller on my Raleigh array Ebike 36v 250w
i had another after market controller previously but I couldn’t get the pas working so purchased a whole new kit
Now I have the opposite problem the PAS works fine, I can peddle 20 mph + with assistance
If I use throttle only it cuts out consistently as 13 mph
it looks to be a battery management issue as the battery shuts down, blue flashing lights on the battery
then starts itself back up 5 or so seconds later
however I have to switch the Ebike controller on again
if I throttle only it will cut again at 13 mph ….
I assume all my connections are ok as the problem is very consistent
I assume the battery is protecting itself as from discharging to quickly?…..
what I’m confused about is my previous set up was throttle only and the battery never cut out…
I’m guessing the controller is pulling more juice than the previous one, the silver box is certainly bigger
is there away to change the settings on the controller to stop this happening
or any suggestions on fixing the problem greatly received

Doc_Wui

Does your S866 have 20 P settings. Look up P12 and P14. First one sets throttle strength. Second one set the amount of current. What's the current rating of the controller?

You probably had a controller rated 12-15 amps for the 250W motor, and a battery capable of 18-20 amps current. If you put on a 25A or 30A controller, then pulling throttle may ask for more current than the battery can supply,. This results in voltage sag that shuts off the battery. Evan a 20A controller, and an old battery could do this,

Setting P14 will limit the max amps of the controller. Change it til the bike quits shutting off.

timchump

Thank you
i think you’re right I’ve noticed the controller is rated up to 750w and I’m running a battery that was set up for a
36v 250 w motor
ive tried reducing down p12 and p14 and it still cuts, but a a higher speed, it cuts out at 13 mph now
if I could get it up to say 16 mph before cutting out I’d be happy

timchump

I just had a test ride and on assistance up a steep hill it still works 10 mph plus, with ease
and i assume it’s under a lot of load in this scenario

speedy25

Bad battery BMS. Common problem.

-SP

Doc_Wui

This is where you try another battery and find the problem goes away. Got a friend with the same bike or battery? How about the shop that sold it to you? It's just the try a known good replacement without actually buying it.

Is the battery/bike still qualify for service? Is the battery old enough to consider replacement.

This is what batteries do when they get ofd.