Battery draining quickly and shuts down at 40%

Hi,

the battery of my Macbook Air 2017 drains really quickly. From a 100% charge it takes approx. 1hr to get to approx. 50% and then shuts down automatically and only turns on when i plug the macbook on.

I did the SMC reset few times already but it did not help at all….

Any advice would be appreciated

I also have seen that the battery shown on my macbook air does not fit what is displayed on Coconut Battery.

Thank you

Shannen