The iPhone 16 Pro Max holds 4,685 mAh

The iPhone 16 Pro Max battery capacity is 4,685 mAh (milliamp-hours). That is the total electrical charge the battery can hold. For context, the previous generation iPhone 15 Pro Max held 4,383 mAh, so Apple added about 300 mAh of capacity this year.

Capacity alone does not tell you how long the phone lasts. A larger battery in a phone with a more efficient processor and display can run longer than a smaller battery in a power-hungry device. The iPhone 16 Pro Max pairs this 4,685 mAh battery with the A18 Pro chip, which Apple designed to use less power than the A17 Pro in the previous model.

Apple rates the iPhone 16 Pro Max for up to 33 hours of video playback on a single charge, or up to 20 hours of streaming video. Those are the official numbers, measured under controlled conditions. Real-world use — with the screen on, apps running, location services active — typically gives you a full day of moderate to heavy use, or closer to two days if you use the phone lightly.

Key Takeaways

  • The iPhone 16 Pro Max battery holds 4,685 mAh, which is about 7 percent more capacity than the iPhone 15 Pro Max.
  • Apple rates the battery for up to 33 hours of video playback, though real-world use depends on screen brightness, app activity, and network conditions.
  • The A18 Pro chip uses less power than the previous A17 Pro, so the larger battery and more efficient processor work together to extend runtime.
  • Battery health degrades over time; Apple estimates the battery retains 80 percent of its capacity after 1,000 full charge cycles.

How mAh relates to actual battery life

Milliamp-hours measure electrical capacity, not time. A 4,685 mAh battery does not automatically last longer than a 4,000 mAh battery if the device drains it faster. The iPhone 16 Pro Max lasts longer than the iPhone 16 (which has a 4,582 mAh battery) not because of the tiny difference in capacity, but because the larger screen and higher refresh rate on the Pro Max use power more efficiently at that size.

What drains the battery fastest: the display (especially at high brightness), location services, video playback, and apps that run in the background. A phone sitting idle with the screen off can hold a charge for weeks. The same phone streaming video at full brightness will drain in a few hours.

Charging speed and wireless charging

The iPhone 16 Pro Max supports 45-watt wired charging with a USB-C cable and compatible power adapter. Apple does not include an adapter in the box, so you need to buy one separately or use an existing USB-C charger rated for at least 20 watts. A 45-watt charger will reach 50 percent charge in roughly 30 minutes under ideal conditions.

The phone also supports 25-watt wireless charging with a compatible Qi charger, and 5-watt charging on older Qi pads. Wireless charging is slower than wired but useful if you have a charging pad on your desk or nightstand. The phone can also charge other devices wirelessly — a feature Apple calls Reverse Wireless Charging — using the same coil.

Battery health and degradation over time

All lithium-ion batteries lose capacity as they age. Apple designs the iPhone 16 Pro Max battery to retain 80 percent of its original capacity after 1,000 full charge cycles. A charge cycle is one complete drain from 100 percent to zero, or the equivalent spread across multiple partial charges.

You can check your battery health in Settings > Battery > Battery Health & Charging. The phone shows you the current maximum capacity as a percentage of the original. If your battery shows 80 percent after two years of normal use, that is expected. If it drops to 50 percent in six months, the battery may be defective.

To slow degradation, avoid letting the battery drain completely, avoid charging in very hot environments, and enable Optimized Battery Charging in Settings. This feature learns your charging patterns and slows charging to 80 percent overnight, then finishes the last 20 percent before you wake up, which reduces the time the battery spends at full charge.

Comparing the iPhone 16 Pro Max to other flagship phones

The Samsung Galaxy S24 Ultra holds 5,000 mAh, which is about 7 percent more than the iPhone 16 Pro Max. The Google Pixel 9 Pro XL holds 5,050 mAh. On paper, both phones have larger batteries. In practice, the iPhone 16 Pro Max often matches or exceeds their real-world runtime because the A18 Pro chip and iOS are more power-efficient than the Snapdragon 8 Gen 3 and Android on those devices.

Battery capacity is one factor among many. Screen size, refresh rate, processor efficiency, and software optimization all affect how long a phone lasts between charges. A phone with a smaller battery but a more efficient chip can outlast a phone with a larger battery and a power-hungry processor.

Fast charging vs. battery longevity

The iPhone 16 Pro Max supports 45-watt charging, which is faster than the 27-watt charging on the iPhone 15 Pro Max. Faster charging generates more heat, and heat degrades battery chemistry. However, the difference in battery lifespan between 27-watt and 45-watt charging is small — measured in months, not years — and only matters if you charge at maximum speed every single day.

If you want to maximize battery lifespan, charge at a lower wattage (20 watts or less) and avoid charging in hot environments. Optimized Battery Charging, mentioned above, is the single most effective setting. For most people, using whatever charger you have on hand is fine; the battery will still last several years before degradation becomes noticeable.

Frequently Asked Questions

Does the iPhone 16 Pro Max battery last longer than the regular iPhone 16?

Yes. The Pro Max has a 4,685 mAh battery versus 4,582 mAh on the standard iPhone 16, and the larger screen on the Pro Max is more power-efficient at that size. Apple rates the Pro Max for up to 33 hours of video playback compared to 27 hours on the standard model.

Can I replace the battery myself?

Apple does not sell batteries for consumer replacement. You can take the phone to an Apple Store or an authorized service provider, and they will replace the battery for a fee (usually around $70 to $100, depending on your location and warranty status). Third-party repair shops also offer battery replacement, often at lower cost, though this may void any remaining warranty.

What is the difference between mAh and Wh?

mAh (milliamp-hours) measures electrical capacity; Wh (watt-hours) measures energy. The iPhone 16 Pro Max battery is rated at 4,685 mAh and approximately 18.1 Wh. Wh is more useful for comparing power consumption across different devices, but manufacturers typically list mAh for phones.

Does leaving my phone plugged in overnight damage the battery?

No, not with Optimized Battery Charging enabled. This feature slows charging to 80 percent and waits until shortly before you wake up to finish the last 20 percent, which reduces wear. Without it, leaving the phone at 100 percent charge for hours does cause minor degradation over time, but the effect is small.

Why does my battery drain faster in cold weather?

Lithium-ion batteries are less efficient in cold temperatures. The chemical reactions inside slow down, so the battery cannot deliver power as quickly and appears to drain faster. The battery is not damaged; it will return to normal performance once it warms up.