Update on Dorado Samsung Batteries (Prodecotech down-tube). I'm using the 38V version and there are two usable versions, without considering Amp-hour ratings It gets slightly confusing as they are almost identical. The Saber lithium, in the Dorado series, is identical to the Prodecotech. The second case version has the usb port on the inside top case cap. The charging port is on the lower case outside. I just got that one. It charges on the prodecotech charger, fits on the frame and runs the bike just fine. I have three of the Saber style also from Prodecotech. The problem is I have two broken top caps needing replacement. The saber style with the four leds, and usb + charging port in back has the only top cap suitable for replacement. I purchased through Alibaba with Dongguan Heyi New Energy Co., LTD The 36 V 17,5 ah battery and two complete frame set connectors for $212 +$74 shipping. The cells are latest version high end Samsung cells. I waited for the new battery before pursuing the top cap order, expecting what I found out about differences. Lindy Chen was my contact at
lindy@heyibattery.com, but it seems like it has to be handled through Alibaba. They will need your motor wattage for BMS matching. Hope this helps someone.