Is the battery original or replaced? What about charge cycles?
Both can be fine. What matters is the battery's current health, not whether it's original.
Charge cycles
A charge cycle is using 100% of the battery's capacity, whether in one go or spread across several charges. Most laptop batteries are designed to keep a good share of their capacity for several hundred cycles; Apple rates many MacBook batteries for around 1,000.
Original vs replaced
- Original, good health: great, and often the best-matched battery
- Replaced with a quality battery: also great, and it may be newer than the laptop
- Replaced with a cheap unbranded battery: can have shorter life
Ask the seller about the battery's health and, if replaced, what kind of battery was used.