Charging for Li-ion is not power, but rate limited, to 15 minutes at minimum. 4C or "4 times as its Ah rating" is considered fastest possible speed within reaso

Charging for Li-ion is not power, but rate limited, to 15 minutes at minimum. 4C or "4 times as its Ah rating" is considered fastest possible speed within reasonable degradation. Up-rating only allows larger battery packs to charge closer to that speed.