Second purchase in 2019 I ordered a little over $1000 USD of stuff. BBSHD mid motor, big battery 52V 17Ah. I assumed everything to work right out of the box. Boy was I wrong on this one. Nothing happened when everything was connected. It turns out the BMS in the battery was bad. What made it worse was that I had 10 battery cells inside the battery that was completely discharged. They sent some replacement parts, but I still had to put in the hours to manually recharge those depleted cells, and solder in the new BMS. Since this time I had more knowledge about batteries and ebikes, I noticed instantly the poor worksmanship of the battery assembly when I opened the case. Unlike the first order, the case was very high quality, because it was sourced from a well known manufacturer. The actual assembly of the cells to the BMS was terrible. Lots of corner cutting when it comes to connecting the cells together in a parallel group, which puts certain nickel plated steel strips under much more current. They also don't use pure nickel strips. The BMS was put on its side instead of on the top of the case, like the case manufacturer designed it to be. Of the entire kit, the only part that was not sourced from another manfacturer was the battery cell assembly, and the worksmanship was horrible. After lots of work to get the battery working I realized I only have 1/3 of the capacity that I was promised. In the end I got $200 USD refunded back to me, which really covered only a little more than what I paid for shipping.
In the end it was a lot of time wasted. The support was always fast, but I realized later on that it wasn't always very knowledgeable support. I questioned them on whether the cells will lose capacity severely before I did any work on the battery and was only told not to worry. In the end I was right and I was the one who lost all that time.