Thank you. I appreciate the info. I contacted them, along with Luna Cycle whose also located in southern California. I ended up buying the largest pack of 18650 cells from Luna Cycle because they had a CHAT feature on their website and someone responded IMMEDIATELY and help me find what to buy right away. I have a couple of bikes, so I've install this 1st battery pack on my first bike and will buy the 2nd pack for my other bike from Hi-Power. I want to compare the 2 vendors and their respective packs personally. On a side note, wish there was a better warranty and customer service program in place when working with these Chinese vendors on Amazon. The prices are much lower but the capacity & performance claims seem to be false and it seems you can't reach the vendor if you have a service or warranty need. Amazon redirects you to the vendor and that doesn't work.