Mac book: Is battery cycle low means mac book still can be used at long time ? I try to buy an old mac book pro mid 2012. Old user of this mac uses mac by electric all the time, so the life cycle till now just 3 cycles, but this computer has been used for 1.5 years.

My question is: if this mac is only 3 cycles, does this mean the battery still as good as new mac ? 

Thanks :)
I can speak from experience that the battery from by 2011 MBP 13' died (like only 10% of designed capacity left) after 56 cycles. It met a precipitous decline after a certain point. You may want you weigh your risk on the cost of replacing the battery.