You can check the rated cycle counts for most Macbooks on the following Apple Support page: https://support.apple.com/en-us/102888 https://support.apple.com/en

You can check the rated cycle counts for most Macbooks on the following Apple Support page: https://support.apple.com/en-us/102888 https://support.apple.com/en-us/102888 Most recent Macbooks should last for 1000 full cycles. Though I'm pretty sure you can brick your battery quickly by keeping it at 100% charge all the time or if you use it in a very hot environment.