To check a second-hand MacBook before buying, hold the Option key, click the Apple menu and open System Information. The Power section shows the battery cycle count, and Hardware Overview shows Activation Lock status. Then watch the seller sign out of their Apple ID and erase the Mac in front of you.
Those checks take about five minutes and catch the two problems that cost buyers the most. A worn battery can need replacing soon after purchase. An Activation Lock or remote-management lock can leave you with a Mac you cannot fully use. This guide shows exactly where to look, what the numbers mean and which answers should make you walk away.
Key facts
- Battery cycle count is listed under System Information > Hardware > Power > Health Information.
- Apple rates most MacBook batteries from the last decade for 1,000 charge cycles.
- On Macs with Apple silicon or a T2 chip, Hardware Overview shows an “Activation Lock Status” line.
- Apple no longer offers a public website for checking Activation Lock by serial number.
- A Mac enrolled in company device management can lock itself again after a full erase.
- A seller who will not erase the Mac in front of you is a serious red flag.
How do I check the battery cycle count on a used MacBook?
You do not need any third-party software. On the MacBook itself:
- Hold the Option key and click the Apple menu in the top-left corner.
- Choose System Information. On newer macOS versions you can also go to System Settings > General > About > System Report.
- In the left sidebar, under Hardware, click Power.
- Under Health Information, read the Cycle Count and the condition.
If you are comfortable with Terminal, this command gives the same figure:
system_profiler SPPowerDataType | grep “Cycle Count”
Always read the number on the Mac yourself. A screenshot sent by a seller proves nothing about the unit in front of you.
What battery cycle count is too high?
One cycle equals 100% of the battery’s capacity used, not one charge. Using 50% one day and 50% the next counts as a single cycle. Apple designs most modern MacBook batteries to keep up to 80% of their original capacity at 1,000 cycles.
In practice, the cycle count tells you how much use the battery has had. Battery health, covered below, tells you how well it has held up. A low count with poor health can point to heat damage or long storage at a full or empty charge. A higher count with good health is often fine. For a fuller breakdown, see our guide on how many battery cycles is too many for a used MacBook.
Where do I see battery health and maximum capacity?
Open System Settings and select Battery. Then click the info button next to Battery Health. On recent macOS versions this shows:
- Condition: “Normal” is what you want. “Service Recommended” means the battery is noticeably worn.
- Maximum Capacity: a percentage of the battery’s original capacity. Anything well below 80% means shorter runtime and a replacement before long.
System Information > Power also shows the condition, and on some models a full charge capacity figure. Check that the Power and Battery screens agree with each other.
How do I check if a MacBook has Activation Lock?
Activation Lock ties a Mac to its owner’s Apple Account through Find My. If it is still on when the Mac is erased, the Mac will ask for the previous owner’s Apple Account password during setup. Without that password, you are stuck.
To check it:
- Open System Information and click Hardware at the top of the sidebar.
- On Macs with Apple silicon or a T2 security chip, look for Activation Lock Status. It should say Disabled.
- Open System Settings and click the account name at the top. Ask the seller to turn off Find My Mac and sign out of their Apple Account.
Be wary of anyone who suggests checking the serial number on a website instead. Apple withdrew its public Activation Lock lookup years ago. The only reliable test is the Mac itself.
How do I check for MDM or remote management?
Mobile Device Management (MDM) lets an organisation control a Mac remotely. Former company or school Macs are sometimes sold while still enrolled. Some enrolments come back automatically after a full erase.
- Go to System Settings > General > Device Management, or Privacy & Security > Profiles on some versions. There should be no profiles listed.
- In Terminal, run profiles status -type enrollment. Both lines should say No.
- During setup after an erase, a Remote Management screen naming an organisation means the Mac is still enrolled. Do not buy it.
Our guide to Activation Lock and MDM explains both locks in more depth.
What should the seller do in front of me?
The safest way to buy a used Mac in person is to watch it being reset:
- The seller signs out of their Apple Account and turns off Find My Mac.
- The seller erases the Mac. On recent macOS versions, use System Settings > General > Transfer or Reset > Erase All Content and Settings.
- The Mac restarts to the setup assistant. Go through setup until you reach a working desktop.
Watch for two things during setup. The Mac must not ask for a previous owner’s Apple Account, and no Remote Management screen should appear. If either one does, stop.
Second-hand MacBook checklist
| Check | Where to find it | Good result | Red flag |
|---|---|---|---|
| Battery cycle count | System Information > Power | Well under 1,000 | Near or above 1,000 |
| Battery health | System Settings > Battery > Battery Health | Normal, high maximum capacity | Service Recommended |
| Activation Lock | System Information > Hardware | Disabled | Enabled, or seller won’t sign out |
| MDM enrolment | Device Management or Terminal | No profiles; enrolment “No” | Profiles listed or Remote Management screen |
| Serial number | System Information > Hardware | Matches the casing underside | Mismatch or seller refuses to show it |
| Full reset | Erase All Content and Settings | Clean setup to desktop | Prompt for previous owner’s Apple Account |
What if I’m buying online and can’t touch the Mac?
When you cannot run these checks yourself, you depend on what the seller tells you. Ask a private seller for a live video call while they open each screen above. Ask them to show the serial number on the underside of the case at the same time.
Online purchases from a business seller in the EU generally come with consumer rights. These include a right of withdrawal and a legal guarantee. Private sales usually do not offer the same protection. That makes per-unit evidence even more important before you pay.
How does the Macs4You Device Passport answer this for each unit?
At Macs4You, you do not have to ask a seller for screenshots or a video call. Every MacBook has its own Device Passport on its product page. It shows:
- the unit’s masked serial number
- its battery cycle count and battery health
- the date it was tested
- verified Activation Lock and MDM status
These are the checks this guide walks you through, carried out on that specific Mac and shown before you buy. Cosmetic condition is graded separately as Excellent, Good or Fair. You can read how that works on how we grade. You can also browse the shop and compare the Device Passport of each unit side by side.