Noob controller question

Controller is rated at 25A Max current. 12A Rated current.

I take that to mean that while the unit can push 25A it can't sustain it for too long and is happier at a mere 12A.

What I don't understand is why i couldn't break 32km/h ~ 20mph with a 48v system while the bike was running on the flats. Motor is a brushless BPM(16) on 26" wheels and I only weigh about 130lbs.

Justin's simulator shows about 40km/h top speed, which I would have thought would be a little closer to the mark.

Reason I'm asking is that I'm in the market for a new battery and was thinking about updating the controller as well, but I'm now wondering if there's much point in the latter. Could it be that the motor winding it what's holding me back?

Thanks for any and all help.

V.

Hi,

Could you give details of the battery type, voltage, Ah, age....?

Also the controller could have a speed limit set up. If you give details of the controller (and LCD display if any) we´ll be able to make you FAST :wink: :wink: :wink:

I don't have the battery anymore, but I believe it was a 13s 10ah limn type. As for the controller, I see no name brand or any such thing, but I cracked it open and it appears to have 12 little fets and no two little white wires connected at a junction (that's the speed limiter, right?)

That's about all the info I can provide.

Product number on the controller is SW765-22 something something. There also another number below that. CE:G3M20211-1592-16.

And on the PCB there's PS12G 280402 if that means anything to you.

Google isn't helping much...

Look at controller and see if the SL pad is jumpered to ground. The SL pad is the speed limiter on a lot of controllers. You should get 40+kph with a 20A controller.

fourbanger said:

... and no two little white wires connected at a junction (that's the speed limiter, right?)

Click to expand...

in my controller the two white wires are the self-study to set the correct rotation of the wheel.

The reason you can't go fast is because you have a slow motor. Code 16 is about 256 rpm at 48v, which is 19 mph no-load speed. With a fully charged battery, you can get a no-load speed of 21.5 mph, which would give about 20 mph on the road. Your controller is not the problem and neither is the battery. If you want to go fast, you have the wrong motor. The only way to make it go faster is to increase the voltage. 72v will give you 30 mph, but you'll need a new battery and controller. It would be cheaper to get a new motor. A code 13 BPM will give about 25 mph, which is a nice compromise between speed and torque. A code 10 will give 33 mph, but will get hot at low speed, so only get that one if your rides are flat.

You can buy just the bare motor for about $160, from which you can then swap the cores, so you don't need to build a new wheel, and it keeps the cost down.

You'll have to forgive my ignorance, but I have no idea what an SL pad is.. Self learning? There's a wee little pcb just kind of hanging there under shrink wrap with one black and red wire going to the controller board on one end (blk to gnd)and 2x red and brown wires on the other end, exiting the box and terminating each with a 2 prong connector PLUS a yellow wire which appears to be grounded at the main board.

Upon closer inspection, there IS a VERY short white wire with fabric insulation going from VL (voltage limiter?) to ground with what appears to be a little resistor of some sort in between.

Thanks for walking me through this, it's starting to feel like I'm getting somewhere.

I'm going to go see if I can borrow a camera.

Oops, didn't see that last post. Thanks D8veh, that kind of confirms my suspicion, though it's a bit of a bummer seeing as how I was hoping to use this bike for hauling cargo/big dog. For some reason I thought 250 would equate to a bit more speed, but there's no arguing with the math, is there? :x

Oh wait, SL = Speed Limiting, doesn't it? Good thing I mentioned something about ignorance.

Thanks for the tip on swapping out the BPM cores. I have a feeling that might come in handy even though it appears the way to go is have one bike for hauling and another for fast.

Found this handy calculator. Maybe it deserves a place in the wiki to spare grade 11 math flunkies like me the trouble of figuring out simple formulas for themselves?

http://www.advanced-ev.com/Calculators/TireSize/index.html

Btw, D8veh, where does one find a reference for BPM (codes) to Kv windings?

Thanks again. As usual.

V.

This one is pretty accurate. The middle speeds are at nominal battery voltage. They're no-load speeds.

http://endless-sphere.com/forums/viewtopic.php?f=2&t=43106

Brilliant, and thanks again. I only wish all vendors were so transparent.

Cheers!

I wonder if you can help me.

I have the same controller (LSW765-22 etc....all the same numbers quoted by fourbanger) and have damaged the circuit board so I need to buy a new one.

can you tell me which bike your controller came from so I can try and source one.

Mine is from an Elite Velocity bike.

It is possible that other controllers would work for my bike but I don't know how to figure out what works and what wont.

David

I missed this. We have the same bike no doubt (Velocity).

Did you get sorted out David?