How "safe" is my laptop running on Service Battery I've had my Mac for over 3 years and I've been good about checking the battery's condition, which was always Normal, but all of a sudden the dreaded Service Battery suddenly showed up.

This was not unexpected, I use my MacBook like a desktop. My Mac is never really moved and is always fully charged (I do take out the cable when it reaches 100% but I put it back in at about 10%). My cycle count is 781 which is only about 3/4 of the battery's life, and I use it hours every day.

My question is, how long can I go with this Service Battery. I do not want to damage my computer but as I'm always right next to the power cord, battery capacity is not a problem.

The help says:


  You can continue to use your battery before it’s checked without harming your computer.


So when will it damage my computer if at all?
I replaced mine (MBP 2009) as soon as possible in the knowledge that Apple only stock replacement batteries for 5 years (source: Apple Genius told me). Mine was 4 years, 11 Months...

Aside from the 'service battery' warning I was seeing wildly fluctuating capacity and a tendency to power down hard at ~20% - so aside from the physical risk you may also risk data loss &amp; file system corruption.