Replacement battery's discharges very quickly

I replaced my MacBook Air’s battery with a good brand replacement battery and this battery discharges very quickly, even when the macbook is idle, the macbook got dusted out and the thermal compound is replaced with arctic mx4, the cpu temp is always pretty good, its the fully specced i7 model. The macbook never experienced water damage and i have a protective sleeve for it when in transit so the macbook never gets dirty on the inside, but this battery still discharges very quickly, in about 1 hour and 30 minutes she goes from 100 percent to 0 and the macbook shuts itself off after it reaches 0.