Testing E-Bike with Minimum Batteries

[Sam Parr]

Hello all,

I'm new here and would like to say hello to all!

I'm also new to E-bikes and was looking for some advice on my first steps on my little project.

I've obtained my Grandads E-Bike (Powabyke Euro MK1 I believe), the batteries have been sat for around 4 years and are completely flat and beyond charging. What I intend on doing is converting the Battery pack to Lithium cells.

First off I would like to do a little test before I gather a good 100 cells together and this is where I am looking for some advice.

The Motor/Controller is 200w/36v.

My test is to run 3 cells in series, so 4v x 3 = 12v, then this three times, so 3 mini packs of 12v, run these in series for 36v, connect up and check it all turns on and spins the wheel.

I don't plan on riding the bike with this little cells, I just want to check everything spins ect and does what it should do!

Can anyone please tell me if there is anything to worry about here or if my calculations are wrong?

I am willing to learn as I really want to get this thing running better than ever.

End plan is to have the original battery case filled with 18650 cells and upgrade the controller/motor.

Kind Regards,

Sam

 

[flecc]

Basically ok Sam, just 9 charged cells in series, should spin the wheel and allow you to check the throttle operates.
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[Sam Parr]

Basically ok Sam, just 9 charged cells in series, should spin the wheel and allow you to check the throttle operates.
.

Hello Flecc,

Thanks for the reply, exactly what I wanted to hear

I have another question, is there a minimum amount of cells that should be used in different scenarios?

Thanks,

Sam

 

[Deleted member 4366]

I don't think it'll work. The Powabyke's controller allows a lot of current (20A IIRC). You didn't say where the cells will come from, but if they're recycled laptop cells or similar, don't expect much more than 1 amp. When the controller tries to drag 20A out of a single cell, the voltage will collapse and trigger the low voltage control (LVC). I think you'Lloyd need two or three cells in parallel to test the motor under no load.

 

[Sam Parr]

I don't think it'll work. The Powabyke's controller allows a lot of current (20A IIRC). You didn't say where the cells will come from, but if they're recycled laptop cells or similar, don't expect much more than 1 amp. When the controller tries to drag 20A out of a single cell, the voltage will collapse and trigger the low voltage control (LVC). I think you'Lloyd need two or three cells in parallel to test the motor under no load.

Thanks D8veh, I'll give it a try and if it doesn't work I'll have to connect more in parallel. The initial testing batteries at Samsung 25r's, but I will not be using these in the final build.