Here it is
http://www.pedelecs.co.uk/forum/threads/how-to-make-a-lightweight-battery.28437/
As i thought he used 20 cells in total (2 layers of 10 cells , 10s 2p formation to get 36v ah from 3000ah cells) but you'd need 26 to get 48v . So you need a bottle that can either fit 13 per layer or...