iPhone Battery Health: What the Percentage Means

Battery health is the first thing most Lahore buyers ask about on WhatsApp, and the number people misread most often. An iPhone battery health check takes ten seconds; knowing what the result does and does not tell you takes a little longer.

Below: where the numbers live, what the percentage measures, what is reasonable on a used iPhone, and what "Unknown Part" means after a replacement. For the rest of the phone, read our used iPhone buyer's guide for Lahore alongside this one.

On every iPhone running a recent iOS version, go to Settings > Battery > Battery Health (on some versions the menu is called Battery Health & Charging). You will see two things:

• Maximum Capacity: the percentage everyone quotes. It compares how much charge the battery can hold now with what it held when new.
• Peak Performance Capability: a line of text. "Your battery is currently supporting normal peak performance" is what you want to see. Anything mentioning unexpected shutdowns, performance management or service deserves a closer look.

On iPhone 15 models and later there is more. Go to Settings > General > About and scroll to the battery section to see the cycle count, the manufacture date and the date of first use. Earlier models do not show cycle count in Settings. Shops read it with computer tools, but a seller's screenshot is a claim, not proof.

Also open Settings > General > About > Parts and Service History where it appears. It shows whether the battery, screen or camera was replaced and whether iOS verified the part.

Maximum Capacity is an estimate of chemical wear. A battery at 86% holds roughly 86% of the charge it held on day one. It says nothing about the screen, Face ID or the board.

• The number moves in steps. It can sit at 100% for months, then drop several points at once.
• The same percentage means different things on different models. Apple says batteries in older iPhones are designed to keep about 80% of their original capacity after 500 full cycles, and iPhone 15 and later after about 1,000 cycles, under ideal lab conditions. So 88% on an iPhone 13 and 88% on an iPhone 16 Pro can reflect quite different usage.
• Heat ages batteries fastest. Two Lahore summers of gaming while charging will show more wear than the phone's age suggests.

There is no official pass mark, but this is a sensible way to think about used iPhone battery health when you compare listings:

• 95-100%: expected on a phone that is only months old. On a phone that is three or four years old, a perfect 100% usually means the battery was replaced, so ask when, where and with what.
• 88-94%: normal for a phone that is one or two years old. Most people will not notice a difference in daily use.
• 81-87%: still usable, but a heavy user will feel it by evening. Treat a battery replacement within the next year as part of the real cost.
• 80% or lower: the threshold people search for as "iPhone battery health 80 percent". At this level iOS may recommend service, and you should value the phone as one that needs a battery soon.

Also ask how many hours of screen time the phone gives on a normal day; that tells you more than the percentage alone. Small phones such as the iPhone 13 mini or iPhone SE have less margin, so wear shows up faster.

Local battery replacements are common in Pakistan, and they leave traces on newer iPhones.

• "Important Battery Message" or "Unable to verify this iPhone has a genuine Apple battery" means iOS could not confirm the battery. On many models the health percentage then stops appearing altogether.
• "Unknown Part" in Parts and Service History means the part could not be verified as genuine Apple. "Genuine Apple Part" means it was verified.

A replaced battery is not automatically bad; a good cell fitted carefully beats a worn original. What matters is honesty and pricing. A phone with an unverified battery should not be sold as untouched.

Be wary of a perfect reading on an older phone with no service history. Some repair shops move the original battery's control board onto a new cell to avoid the warning, so the percentage may not describe the cell inside. If the story and the numbers do not match, walk away.

1. Open Battery Health yourself on the phone in your hand. Do not rely on photos.
2. Read the Peak Performance Capability line, not just the percentage.
3. Open Parts and Service History if your model shows it.
4. On iPhone 15 and later, compare the cycle count and first-use date with what the seller told you about how long it was used.
5. Go to Settings > Battery and look at the activity graph for the last 24 hours and 10 days. Sharp drops with little screen time are a warning.
6. Record a few minutes of video or run a game, and watch the percentage and the heat. A phone that shuts down at 20-30% has a battery problem.
7. Plug it into a charger you trust and confirm it charges. On iPhone 15 and later, a phone that stops at 80% may simply have the charge limit turned on, which is a setting, not a fault.
8. Look along the edges of the screen. A lifted display can mean a swollen battery, which is a safety issue, not a bargaining point.

If you want a wider picture of how a phone's overall condition is graded, our explainer on used phone condition grades covers the rest.

A weak battery on an otherwise healthy, PTA approved phone with a clean IMEI is a negotiation point, not a dealbreaker. iPhone battery replacement in Lahore is routine, so get quotes before you buy. Ask whether the battery is a genuine Apple part or a third-party cell, whether a warning message will appear afterwards, and what warranty covers the battery itself. Cheap cells can lose capacity quickly in summer heat.

Walk away if the battery is swollen, there are water damage signs, or the seller's story keeps changing.

Every iPhone listed on our iPhone page shows battery health or cycle information when we have it. Message MacVault on WhatsApp for a live photo of the Battery Health and Parts and Service History screens of the exact unit, and read our warranty notes to see what cover applies before you pay.