Real weight of my 4pcs is only 46g (don't know why here is written 64g). The real capacity tested on professional laboratory equipment (current - Kikusui power load, voltage - Tentronix scope) is ONLY less than 750mAh !!! at continuous 10A discharge current (what is 10C). After discharge the temperature was ok, about 50degC. Load characteristic of 8 cells (4 batteries) is attached.