Match Ebike Controller amps with Battery

Anio58

10 mW
Joined
Mar 3, 2022
Messages
28
I have a 350w motor and a 48v 20ah battery (will upgrade to 30-40 ah later date) The controller I am looking at is a 350w current limiting 13amp. I know it won't climb steep hills. But, is this a good current limiting for a 48v 20ah and higher ? But I do expect to go up slanted hills, correct.
 
Anio58 said:
I have a 350w motor and a 48v 20ah battery (will upgrade to 30-40 ah later date) The controller I am looking at is a 350w current limiting 13amp. I know it won't climb steep hills. But, is this a good current limiting for a 48v 20ah and higher ? But I do expect to go up slanted hills, correct.
A 48V 20Ah battery, even with generic cells, should be able to supply 13A comfortably, likely more; so the 13A limit will protect the battery from too much current. 13A at 48V would be 624W peak, which should be fine for the motor, if you're not running at that level for long periods. The hill question depends on the hill. 350W-624W won't allow you to ride throttle only up steep hills, but will provide a decent amount of assist while you pedal.

You need to provide specifics about your battery, motor, controller, steepness of the hill, and your total weight in order to know more about how it will actually perform.
 
Anio58 said:
Update
I have a 350w motor, 13+1amp controller and a 48v 20ah battery (will upgrade to 30-40 ah later date) it will go up a 25 degree hill easy enough.
The controller I am looking at is a 350w current limiting 13amp. I know it won't climb steep hills. But, is this a good current limiting for a 48v 20ah and higher ? But I do expect to go up slanted hills, correct. The question is will a 13 amp controller take me up a 25 degree hill as easy as a 13+1 amp controller ?
 
How many watts per hour does a 48v 20ah battery use on a 350w ebike ? With speeds between 14-18 mph ?
 
Would this be going 14-18mph going up hill, or down? Wind at your back, or in your face? On sand, grass or pavement?

Point is, there's way to many variables to give much of an answer to your question.
 
AHicks said:
Would this be going 14-18mph going up hill, or down? Wind at your back, or in your face? On sand, grass or pavement?

Point is, there's way to many variables to give much of an answer to your question.
Watts per mile as calculated by most e-bike manufacturers:
... downhill, tires inflated to 120 PSI, 75 MPH tailwind, smooth as glass pavement minus 10% fudge factor.
 
https://ebikes.ca/tools/simulator.html
https://ebikes.ca/tools/trip-simulator.html

Weight
How much you pedal
Slope
Wind
Stop & Go type riding
Temperature is a big factor as well buddy, dont forget that.

Read on buddy
https://ebikes.ca/learn/batteries.html
Go down to the bottom and look at that chart, yeah you gotta do the conversion buddy.
All I know is its times 1.6
or use this chart https://www.aqua-calc.com/convert/electric-car-energy-economy/watt-hour-per-kilometer-to-watt-hour-per-mile
As a general rule @ 270lbs no major hills, and lazy pedaling 50wh/m, v x ah = wh
 
Does your battery have a BMS?
What is your battery rated for in terms of amp discharge?
Choose your controller wisely, dont go too wimpy on the power mate, otherwise you got to buy more stuff. Everything is based around the battery. If it has a BMS then the battery will stop when the voltage gets to low.

DO NOT BELIEVE FOR ONE SECOND YOU HAVE THE SELF CONTROL TO NOT HAVE A BATTERY BMS OR HAVE TOO LOW CONTROLLER LVC. Example is having a 36v controller with a ~30-31v lvc but using a 48v battery without a bms then say bye bye to battery. 48v is ~39-40v for 3v/cell of 13s (48v), deplete your 48v to 30v (10v lower) and bye
 
I have an ebike 48v 350w 13+1 amp controller. I can easily go up a 25 degree hill. But I want to switch the controller but it is only 13 amps. Would I still be able to go up hill as easily ?
 
Try it out or you day dreaming or actually buying, most likely a long stage of "learning" what to buy. I get it, mostly I dig it.

Sense wire shunt mod
Your welcome :wink:, there is a risk of bricking the controller but if you got a steady, sober hand on that soldering iron and just that right touch to plop that solder on, evenly on all sense wires. Steady now, trick is do you use thick solder and risk putting too much on, or do you use too thin a solder and have to use a mile of it. Then, how do you measure phase and battery amps to see how much of a gain it was, and hopefully it wasnt too much to fry some sensitive signal somewhere, their all truthfully stout and strong if not abused.

Or you just go up a bit in amp rating on the controller if you find there isnt enough power.
from ----> 36v 10a is 360w
- Not sure how much you'd gain on the solder shunt mod. But buying, I'd jump 15a, can always shave the shunts to lose some power, much easier then adding solder, depending on your hand/eye soldering skills
36v20a is 720w
36vx25a = 900w <------ to here, if not 36v30a, hey your choice, its a free world. Are you scared?


Anio58 said:
I have an ebike 48v 350w 13+1 amp controller. I can easily go up a 25 degree hill. But I want to switch the controller but it is only 13 amps. Would I still be able to go up hill as easily ?
 
Anio58 said:
I have an ebike 48v 350w 13+1 amp controller. I can easily go up a 25 degree hill. But I want to switch the controller but it is only 13 amps. Would I still be able to go up hill as easily ?
Can you post a pic of your bike? I'm interested in seeing what a 350W bike that can climb 25 degrees easily looks like, and the components used. a video would be even better.

10 degree hill, so your hill is two and a half times steeper. is that with pedaling?:
file.php
 
Lol I guess it is a little less than that ? But I am wondering if a drop from a 13+1 amp controller to a 13 amp controller would make a difference in a hill climb ?
 
Anio58 said:
Lol I guess it is a little less than that ? But I am wondering if a drop from a 13+1 amp controller to a 13 amp controller would make a difference in a hill climb ?

It depends on what 13+1 means. It could be that it's rated at 13A, and can output 14A peak/burst.

Different controllers rate current between continuous and peak differently, so the 13A controller may even provide more power than the 13+1, but my guess is you won't be able to tell the difference.
 
Back
Top