iFixit MacBook battery doesn't last very long

Hi all,

I purchased and installed a new battery for my device in December of 2018, as the stock one had over 1000 cycles and performance began to degrade significantly. I noticed that the mAh capacity in system information was quite a bit lower than the Apple stock, and it displayed “Service Battery.” I stuck with it though as I didn’t think much of it. Recently the battery life has dropped to unacceptable levels, almost dropping 30% after a 45 minute class where I typed up Google Docs in Safari. Steam runs in the background, but it shouldn’t have that much of an impact.

I’ve included screenshots from CoconutBattery and Activity Monitor if it helps. Thanks for your time.