Tips:

Do not put LP-E6 internal battery into BMPCC4K when using this high power external battery,  according to the BMPCC4K internal charging circuit design, if charge the LP-E6 by this external battery, charging current very high (reach to 18W) it’s easily to damage both the LP-E6 battery and external battery. That’s why many photographers feedback LP-E6 charged by external battery very fast, it’s more safe that charge Lp-E6 by the normal power below 7W but not by this External Battery.

Actual tested: this External battery supply power to BMPCC4K continuously record video last 4 hours.