Worth real money · 30 seconds

How much life is left in this battery?

A battery is the one part of an Apple Silicon MacBook that wears out on a schedule, and the only fault a seller can rarely argue with. Two numbers settle it: how many charge cycles it has done, and how much of its original capacity remains.

Do all of it in one step ›

The one-command system check reads the cycle count, capacity and condition for you, alongside the ownership locks and drive health, and grades all of them together.

Step one

Run this in Terminal on the seller's Mac

system_profiler SPPowerDataType | grep -E "Cycle Count|Condition|Maximum Capacity"

Open Terminal with ⌘Space, type “terminal”, paste. No password, no installation, nothing written to the machine.

Step two

Paste what it prints back

Waiting

Nothing pasted yet

Paste everything the command printed, including the lines that look like noise. Reading the whole output is what stops a half-answer being graded as a pass.

Step three

Turn the numbers into a discount

Cycles	Capacity	What it means	What to ask for
Under 250	90–100%	Barely used	Nothing to deduct
250–500	85–89%	Normal for its age	Nothing to deduct
500–800	80–84%	Worn, still usable	Deduct $50–80 — it will need doing
Over 1,000, or “Service”	Under 80%	Past its rated life	Deduct $150–200 — Apple’s swap price

Cycles and capacity can disagree — a lightly used Mac left plugged in for three years often shows low cycles and poor capacity anyway. When they disagree, believe the capacity: it is what you will actually feel.

A worn battery is not a reason to walk away

Unlike the ownership locks, this is a fixed price to put right, and Apple will do it on any Apple Silicon MacBook. Treat it as a line item rather than a deal-breaker — then check the charger is in the box, because a genuine one is another $60 to $100.

Know the battery. Now check everything you can’t see.

Run the full inspection

If the charger is missing

Genuine-spec MagSafe 3 cables and GaN adapters that actually deliver full wattage

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