Hi I'm Robin from Finland. Owner of a Faraday Motion Spine.
I decided a while back that I would put a 10s4p 18650 battery pack under the spine. This battery pack would hold 370 Wh using Samsung inr18650 25r 2500mah .
@SunePedersen Will be the one spot welding the pack for me. Thanks for the help!
Last week the part´s needed to build the pack started to drop in the mailbox. I got the
: Charger.
: BMS.
: Vedders spark protection switch with a fuse.
: Charging jack, Heatshrink wrap etc.
So it was about time to start this project.
First thing I did was to remove enough material under the board so the pack would eventually fit there.
Then I attached aluminium strips along the sides of the board with popnit´s for strenghtening the board. It turned out okay.
Then it was time to start thinking of an enclosure for the board. 3d printing was the way to go for me so I had some thinking to do how to get it to fit good. It was not the easiest thing to sketch but I think I got the geometry just about right so it would fit under the board protecting the battery and electronics. Printing it for the first time now. let´s see how it goes.. And modifications needs to be done to the enclosure when I get the battery pack In my hand so I can make the right path for cables etc.
Next friday I have the opportunity to play with a cnc lathe for a whole day, so I will make 4 aluminium hubs for my 200mm Pedal hard tires. Feels a bit unsafe riding with 3d printed hubs atm 
To be continued
//Robin