Diy build. Questions questions, so many questions

I have a few questions.
if i have a 48v controller, can i use a 54.6v battery?
what are the bare minimum components required for an ebike?
motor, controller, battery, accelerator, and bike?
are there any ways to test controllers?

basically ive been trying to build an ebike from used laptop batterypacks. ive manager to build a few batteries but recently i havent been able to get anything to work. i dont know if im just buying from bad suppliers or maybe shorting things out before they have a chance to run. i have no idea why nothing wants to work. the only thing in this rig that isnt brand new is the motor. maybe thats blown idk

also im not using a bms at the moment till i can get at the very least a motor spinning
wierd thing i just noticed about the controller, it says it can handle 48v at 45a and its 1000w the math doesnt add up on that i dont think, maybe thats peak amps or something. idk

The first photo looks like the motor has hall sensors. The 5 small hall sensor wires are unconnected. The fourth photo looks like the controller has the white 5 wire plug with green latch that should be a hall connector , more help here : https://endless-sphere.com/forums/viewtopic.php?f=16&t=3484

I would start with a known good battery pack, you have too many other unknown variables there.

Yes that alone may cost more than the rest of your drivetrain, but if you treat it right might last for years, depending on duty cycle of course.

With scrapped cells you might only get a month or two then have to start over.

Yes , there is a tester that will test motor , controller , throttle . You can find them on Amazon , Ebay, etc, - example : https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2380057.m570.l1313.TR1.TRC0.A0.H0.Xebike+tester.TRS0&_nkw=ebike+tester&_sacat=0. I have one with insulated alligator clips on all the leads. Yes , 48V controller usually will work at that voltage. Do you have any controller wiring info from the seller ? Looking for a thin red wire that also needs to be connected to battery plus.

DaTree said:

if i have a 48v controller, can i use a 54.6v battery?

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The fully charged voltage of a nominally 48V lithium ion battery is 54.6V. Your controller should be good for at least 60V actual measured voltage.

what are the bare minimum components required for an ebike?
motor, controller, battery, accelerator, and bike?

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For a brushless DC motor:
Motor
Controller
Battery
Source of throttle signal

Furthermore, the controller usually needs Hall sensor signals and a jumper or switch on the enable wire.

are there any ways to test controllers?

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Yes. But you're not at that point yet. The best way to test a controller is to connect it to all the things it requires to operate.

Make sure your Hall sensor leads are connected. Usually, that's a plug with 5 or 6 wires going to it: yellow, blue, green, red, black and sometimes white. If the motor and controller were bought from different sources, the phase sensors (Y/B/G) may not correspond correctly. Red is +5V and black is GND. I'm not sure what the white wire is for when it's present, but I've never needed it to get a motor and controller working together.

Determine which 2 wire plug is your enable wire. If it's marked, it will say something like "power" or "key switch". You can use a jumper wire for now. If one of the 2 wires on this connector has an open terminal on the other end, that one must be attached to the battery positive voltage.

wierd thing i just noticed about the controller, it says it can handle 48v at 45a and its 1000w the math doesnt add up on that i dont think, maybe thats peak amps or something. idk

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1000W is the rating of mechanical output power the motor can produce continuously without overheating. It represents a bunch of assumptions about operating conditions that may or may not apply to your bike. But if there's a V x A input power rating, your motor can withstand at least that much for at least a little while. The output power will be less, and the difference will be discharged as heat into the motor.

so from what you guys are telling me i need to connect that red switch plug line from the controller to the positive lead on my battery. then somehow connect the hall sensor up. and i shouldnt need to do anything with the extra white line coming from the motor.

48V battery usually has 13 cells in series. 13 X 4.2 v per cell = 54.6.

if you have 12 cells in series, 50.4 is fully charged. 48.6 would be 4.05 for 12S, a bit low, but workable.

13S the motor spins faster. Voltage is speed regulation, essentially.

Controller should have LVC, low voltage cutoff. Varies among controllers, 3.x per cell, you should be OK on voltage. At least to check function. Will need likely 4 or more in parallel, yes, 50-60 cells. Testing should work with any P count as long as 48V ballpark is achieved.

Halls and Phase wires - thin set is Halls, Thick ones are phase. Some motors do not have Halls. Sensorless. Some controllers will run that way, but best not from a standing start. Check procedure at Ebikes.ca for matching, there is NO guarantees colors will match. Read carefully. Primary caution is extreme minimal throttle when testing. Hi throttle with bad combo can do damage. One combination works forward, correctly, one in reverse, a couple dozen combinations.

Self-learning is to auto detect phase and Hall order. Looks like you have an "ignition" wire, essentially an "on" button. IF that diagram is not specific to your controller, then do not rely on it. MUCH, much variation.

Used Cells - doable, but need many in parallel for any range. Look up DrkAngels threads on testing and capacity matching, very important. Many good tips there. Power tool cells are better than laptop cells, high-current draw is needed for ebikes.

Controllers are fairly cheap, but need to be at least vaguely matched to motor.

Ive tested all the cells im using. its 4p12s right now but i can change that back to 13s easy.
Only thing im really worried about now it that red switch plug wire that ive circled.
would that be connected directly to the possitive lead on the battery along with the other red wire for power?