I recently purchased a 48v 20ah battery from ebay. The seller was Leebenmr. The problem is that the seller did not include the BMS that was stated in the description. I will never buy another battery from this seller again. I have emailed him several times and he told me it was built inside the battery pack, I opened the pack and did not find the BMS. He wants me to send it back to give me a refund but i think its pointless because i will probably spend as much money in shipping than what i paid for it. One of the cells also seems to have been damaged during shipping, I will try to replace it with another one. The pack is composed of roughly 300 AA sized cells in stacks of 20. There are 15 tabs on top of the cell where i beleive the BMS should be connected. I contacted Ping and he told me it should be 16 tabs. I will probably purchase the BMS from ping and add the missing tab but i need help figuring out where each wire plugs in for the BMS.