DIY 18650 20 Ah 36 V -- pipe pack

Hi everyone!

I just want to share a way to make simple and rigid battery pack for your ebike..

My goal was to make simple, stealth, cheap and good battery pack. I came up with idea to put batterys in sewage PPE 110 mm pipe. It is not finished yet but i will post progress in this topic. Any comments appriciated.

Price of components:

70x panosonic NCR18650PF = 210 €
1x PPE sewage pipe = 5€
wood frame = 5 €
end covers = 10 €
BMS = 10 €

In this pipe is enough room for 350 W controller and BMS.

I'm about to make connections today.

What do you think of tesla styl fuses yes/no?

Here is my progress.

i decided to go with tesla style fuses. Pack is bolted together (you cant see on this picture) but i will also use some more hot glue to make it even more rigid. I'm a bit worried that vibrations could damage connections.

Fuses are 0,3 mm copper wires (12 A). I'm impressed how well is everything soldering together. I would finish this in one hour but i had a long visit from my friend ...

Looks awesome and safe. I hope that pipe is not welded part of the frame eh? ;D

Just2807 said:

Looks awesome and safe. I hope that pipe is not welded part of the frame eh? ;D

Click to expand...

Thx. No, pipe is plastic and is not part of the frame

Today i finished with battery... im still waiting for BMS. One was lost on way from China. I ordered second BMS from UK. But i tried to charge battery today with 2.1 A 41,6 V (hoverboard) charger and i cant belive but cells are even full to the 4,03 V (i disconected the charger before reaching 41,6 V).

I used more hot glue to secure cells in place. Pack feels like solid brick

Im satisfied with results for now. Now i just have to finish pipe end covers and pipe holder. This is low power bike, 15A max so im thinking that there is no need for vent holes.

How it fits the 110 mm pipe:



Finished soldering:



When you forget to change mode on multimeter from current to voltage it melted my multimeter rod.

Hi everyone!

i will upload finished pack pictures but i have one question..


today i charged the battery and then i wanted to check the voltage on charging pin.. i made a nasty shortcut...

Arc melted 1cm of my multimeter rod and bike was not working any more..

i disasambled the pack and check for damage.. there is no visible damage. and the voltage readings in charging pin and output pin form BMS are normal.

Do you advise to change BMS? or this is normal..

i use this bms:

Im satisfied with result.. nice and easy to use commuter bike with top speed of 35kmh on flat.

End price 500 €..

use some extra protection on the positive side from the cells and some kapton tape-fishpaper between bms wires/main positive negative wires.
Nice pack for 500$