Only 20% after 20 miles, is fantastic. I do not get anything close to that on a 36V 11.6ah with original cells riding flats with not much wind with a 140lb rider at that. I'll usually top out at 30 miles on a full charge while riding in a high PAS level. Great update for everyone to see how an upgrade is worth every dollar put back into your E-bike riding experience. Sounds like you now have 1-1/2 batteries on your bike.Got a great deal. Only charged me $500 for replacing 100 cells, 18650, 3500mah each, Samsung.
After 20 miles, dropped to 80%