Sw 900 controller

Downhill fast

100 µW
Joined
Mar 21, 2022
Messages
7
Hi I recently bought an E bike and messed with controller. It is a 2000w hub drive and was only drawing 760 W at max power . It's a 48v 15 ah. I turned down p7 to 38 an 14 to 15 . Now I'm not sure if I've wrecked it, today rode better more power . Can anyone tell me correct settings PLEASE. 2000W 48V 15AH ,SW 900 CONTROLLER .also set pas magnets to 5 . Bike is a Cullen v4
 
Downhill fast said:
Sorry I'm new to this ,it's all covered up the controller. The display needs setting it's sw900 .
The settings have to match the hardware (controller/battery/etc.).

Can you list all of the P settings (P1-P16) you are currently using?
Also, the type of PAS sensor the bike uses, or a picture.
 
power is voltage multiplied by amps.

so your 48v x 15a is 720 watts max. if you want your motor to run at 2000w at 48v you will need a controller than can push 41.6666amps.

your controller does say "max current (amps) 25) in your pictures though.... so it should be closer to 1200watts.

ive noticed that many of the sw900 settings dont work or show no change. the main one being that changing or limiting your amps with the p14 setting does nothing to limit max power or amp draw.

maybe your lucky and your controller has this function enabled....mine doesnt.

either way your gonna need a lot more amps.

also....more amps is more torque/acceleration, a beefier 48v controller will still give you a similar/identicle top speed.
 
also..... you may have a three wire cable, one black wire and two other different colours.

labled "speed" or "gears"...or something similar. (maybe no label at all).

leaving it as is (not connected) will be middle power/speed.
and connecting the black (ground) to either of the two other colors will be high and low speed.

these three modes are usually/roughly 50% 75% and 100% power/speed.

(ive seen some adverts say its 75% 100% 120%)
but i think they've watched spinal tap too much.
 
Downhill fast said:
I'm going to increase the amps .I thought that ,p14 was my battery ah ,again thanks ,I'm learning

You're limited by your battery. If this is the bike, then eyeballing the battery, it looks like a 13S5P pack.
https://www.cullenebikes.com.au/product/2000w-48v-15ah-hydraulic-cut-off-brake-lever-27-5x2-1-rim-cullen-version-4/

They call it a 1000W pack, because that's likely the most it can output, around 20A.
https://www.cullenebikes.com.au/product/48v-15ah-1000w-hailong-li-oin-battery-electric-bike-downtube-battery/

The price of the pack, $389, means most likely it's made of generic cells. The same pack made with Samsung 30Q cells, for instance, would cost around $550, and even with those cells, would be rated at around 30A continuous (1440W), and 14.5Ah.

You could ride it as-is and invest in a 52V pack and get a performance and speed increase. The stock controller and display can likely handle the voltage increase.
 
hopefully if they sold it as 2000w they would of provided a battery that can handle that amperage.

but i get what you are saying. ive found most "honest" 18650s are happiest at 1c discharge rate, and can maybe do 2c-3c at a push.

that 48v 15ah battery....at 2000w is nearly 42amps. 2.8 c which id say is on the limits.
 
Don't forget: A controller doesn't "push" amps.

It can only provide the current the motor asks for, which will only increase when the load on the motor increases.

So you can set the settings as high as they'll go, and have as big a battery and motor and controller as you want, but if your load isn't high enough, it won't even try to draw more power than it already does.
 
fair point, bad choice of words (provide is better?), i found that hard limit on my little 14" unicycle hub motor dirt bike thing.
no difference between a 1500w controller and 1000w in performance, and even the middle and high speeds were the same

it seemed a bit weird as its nearly the same size rotor, hub and magnets as my 1000w rated hubs.
i guess the mechanical advantage of the teeny tiny diameter means it never asks for more than 700ish watts.

makes me wonder as ive seen people run the 26" 1000w hubs at 6000w. will mine pull 6000w if i let it?
 
Not if you "let it".

If you put enough of a load on it, and

the controller is capable of providing that much power, and

the battery is capable of providing that much power, and

the wiring is capable of handling that much power, then

yes, the motor will draw that much power, until it fails from overheating or it or it's mounting system fails from physical stress (torque).


Given the ability to supply the power to do it, you can stall a hubmotor (put a stick in the spokes and try to spin it) and it will draw as much current as the battery voltage and winding resistance allows, until the smoke appears, the stick breaks, the spokes fail, or the axle mounting system lets it spinout and rip the wiring apart and short everything out.
 
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