DIY e-bike

[Robjohnb]

Hello Pedelec's

Just joined the forum and thought I would share my DIY e-bike build if anyone is interested.

The e-bike parts are from bmsbattery.com, fitted to a Ridgeback momentum bike.
The battery pack is home brewed from 5 pc laptop battery packs, 40 lith-ion cells plus the BMS. 270wh.

Have done 12 mile commute in 50mins, ave speed 14mph with little effort. Mostly pedal assist.

Regards, Robert

 

[Deleted member 4366]

Is that a Q100H? If so, I think a few people would be interested in performance statistics. That battery looks interesting too.

 

[trex]

nice job! and welcome to the forum.
Could you post more pictures of the build? I am also interested in your battery solution.

 

[Robjohnb]

Is that a Q100H? If so, I think a few people would be interested in performance statistics. That battery looks interesting too.

Yes, Q100H 36V, LSW-675 controller.
I have logged some ride data using the sports-tracker app. Need to make the data public then anyone can view online.

Rob

 

[Robjohnb]

nice job! and welcome to the forum.
Could you post more pictures of the build? I am also interested in your battery solution.

Thank you, what would you like to see? It's pretty basic construction.
The batt pack is 40 1800mAh lith-ion cells. These are 10 series by 4 parallel, giving 37V at 7.2Ah. There is a BMS for charge and discharge.
Batteries fitted into some square PVC drain pipe! this slotted nicely into the drink bottle holder then some velcro strap at the top of pack.

Regards, Rob

 

[trex]

...
Batteries fitted into some square PVC drain pipe! this slotted nicely into the drink bottle holder then some velcro strap at the top of pack.

Regards, Rob

it's simply inspiring. Could you post some more pictures of the battery?

 

[Robjohnb]

it's simply inspiring. Could you post some more pictures of the battery?

Some degree of caution was needed when building the batt pack. A lot of energy there and easy to start a fire. Opening up PC laptop packs is not straight forward either. Only attempt this if you're 100% sure of all risks and familiar with electronics.

Rob

 

[Robjohnb]

Have been using the e-bike for several work commutes now and achieve the 11.5miles in 50mins. Typical PAS speed 18-20mph (limiter to be set . Above this, the motor Q100H 36V 201rpm on 700c seems to run out of drive. I calculate 201rpm to be about 15mph for 700c. So with PAS the 201rpm goes up a little.
Is using a higher voltage an option? Has anyone tried?

 

[Deleted member 4366]

You can buy a 360 rpm Q100H bare motor. When you get it, swap the core with the motor in your wheel. That will give you 30% extra speed for £87. You can then sell your 201 rpm motor on Ebay, and get back probably £50.