I was on Catalina with my 2009 MacBook Pro (5,5), and my battery indicator was saying "Service Battery". Given that the battery is the original one from 2009, I'm not surprised. However, I backed down to High Sierra and the message no longer appears. System Information says the battery condition is "Normal".
It would be good to know in which version of macOS this Service Battery message shows up in case I want to buy an older Intel Mac.
BTW, I'll note that it only has 328 cycles despite being over 12 years old, because I kept it charged up most of the time. Often it was sitting on a desk plugged in. And then in the last few years it just wasn't used much since I had another 12" MacBook. In contrast, the 2017 MacBook Air I just bought has over 460 cycles and has much longer battery life.
It would be good to know in which version of macOS this Service Battery message shows up in case I want to buy an older Intel Mac.
BTW, I'll note that it only has 328 cycles despite being over 12 years old, because I kept it charged up most of the time. Often it was sitting on a desk plugged in. And then in the last few years it just wasn't used much since I had another 12" MacBook. In contrast, the 2017 MacBook Air I just bought has over 460 cycles and has much longer battery life.