How Long Did It Take to Fully Charge the Original iPhone vs iPhone 18 Pro?

The iPhone has changed dramatically since Apple introduced the original model in 2007. Over nearly two decades, Apple has improved displays, processors, cameras, battery capacity and, perhaps most noticeably for everyday users, charging technology.

One interesting comparison is how long it takes to fully charge an iPhone today compared with the very first iPhone.

The difference highlights just how much smartphone charging has evolved.

The Original iPhone Was Surprisingly Slow to Fully Charge

Apple's first iPhone launched in 2007 with a relatively small 1,400mAh lithium-ion battery.

Despite its limited battery capacity compared with today's smartphones, the original iPhone could provide up to several hours of use, including around eight hours of talk time and seven hours of video playback.

However, charging the battery to 100% was not particularly quick.

Based on charging tests from the period, the original iPhone could reach approximately 90% in less than two hours. Getting from 90% to a complete 100% charge required roughly another hour and a half.

That means a completely depleted original iPhone could take around three and a half hours to fully charge.

Modern iPhones Are Much Faster

Fast-forward to 2026, and Apple's charging technology has improved considerably.

The latest iPhone generation can recover a large amount of battery power in a fraction of the time required by the original iPhone. For example, the iPhone 18 Pro can reach around 50% charge in approximately 15 minutes under supported fast-charging conditions.

That makes a short charging session much more useful for people who need to quickly top up their phone before leaving home.

The improvement becomes even more impressive when comparing the battery sizes.

Battery Capacity Has Increased Dramatically

The original iPhone had a battery capacity of approximately 1,400mAh.

Modern Pro Max models have batteries several times larger. The iPhone 18 Pro Max, for example, is reported to have a battery capacity of around 21.75Wh.

In other words, today's iPhones have much larger batteries while also being capable of charging them significantly faster.

This is an important distinction because battery technology itself has not advanced as quickly as processors, displays and cameras.

Much of the progress users notice in charging has instead come from improvements in charging power, power management and charging standards.

Fast Charging Changed Everything

Fast charging became increasingly important in smartphones during the 2010s.

USB Power Delivery, commonly known as USB PD, became one of the major standards for delivering higher charging power through USB-C. Apple and Google are among the companies that use USB PD for fast charging.

The important point is that having a powerful charger doesn't automatically mean every phone will charge at the same speed.

A smartphone controls how much power it draws based on its hardware, battery condition, temperature and charging stage.

Why Does iPhone Charging Slow Down Near 100%?

You may notice that an iPhone charges very quickly at the beginning but becomes noticeably slower as it approaches full capacity.

This is intentional.

Lithium-ion batteries require careful power management, especially when approaching maximum charge. Reducing charging speed helps control heat and battery stress.

As a result, charging from 0% to 50% can be much faster than charging from 80% to 100%.

This is also why a phone that advertises extremely fast charging doesn't necessarily reach 100% in the same proportion of time.

Wired Charging vs Wireless Charging

Wired charging remains the better choice when speed is the priority.

Wireless charging offers greater convenience, but it generally takes longer to reach 100%. Earlier iPhones using conventional Qi charging could take several hours to complete a full charge, while MagSafe provides a faster wireless option but can still be slower than a suitable wired connection.

Wireless charging can also generate more heat, which may further affect charging speed.

Why Charging Speeds Differ Between iPhones

Several factors can determine how quickly an iPhone charges:

• Charger power: A higher-capacity compatible charger can provide faster charging.
• Cable: The cable must support the required charging standard.
• Battery capacity: Larger batteries generally require more energy to reach 100%.
• Battery health: Older batteries may behave differently during charging.
• Temperature: iPhones can reduce charging power when they become too hot or cold.
• Phone usage: Gaming, video streaming and other demanding activities can consume power while charging.
• Charging percentage: Charging generally slows as the battery approaches full capacity.

USB-C Has Made Charging More Convenient

The move toward USB-C has also made modern iPhone charging more convenient.

USB-C is widely used across smartphones, tablets, laptops and other electronics. This means consumers can increasingly use the same charging accessories across multiple devices, provided the charger and cable support the necessary power requirements.

It also makes it easier to find compatible third-party charging accessories.

The Biggest Change Isn't Just the Battery

It would be easy to assume that modern iPhones charge faster simply because their batteries are better.

The reality is more complicated.

Battery capacities have grown substantially, but the biggest practical improvements have come from charging hardware and power-management technology.

Today's smartphones can intelligently adjust charging power throughout the charging cycle. This allows them to quickly add a significant amount of battery when needed while slowing down later to manage heat and battery longevity.

Original iPhone vs Modern iPhone

The difference between Apple's first iPhone and today's models is remarkable:

What Does This Mean for iPhone Users?

For everyday users, faster charging means you don't necessarily need to leave your phone connected for hours.

A short charging session while getting ready for work, eating lunch or preparing to leave can provide a substantial battery boost.

This is particularly useful for people who frequently use navigation, cameras, gaming, video streaming or mobile data throughout the day.

Final Thoughts

The evolution from the original iPhone to today's models demonstrates just how much smartphone charging has changed.

In 2007, completely charging an iPhone could take several hours. Today, modern iPhones can rapidly replenish a significant portion of their battery in a matter of minutes.

While battery chemistry itself has not experienced the same dramatic transformation as other smartphone technologies, improvements in charging standards, power management and hardware have made modern iPhones far more convenient to recharge.

The original iPhone changed the smartphone industry. Nearly 20 years later, faster charging is one of the many areas where Apple's smartphones have come a long way.