The iPhone 4 may be an older model, but many users still rely on its compact design and classic iOS experience. Over time the original battery loses capacity, causing unexpected shutdowns and shorter talk time. Replacing the battery with a modern, high‑capacity unit can restore the phone’s original performance and extend daily use without a charger.
In this 2026 review we evaluate five replacement batteries that have proven reliability, safety certifications, and solid user feedback. Whether you need a budget option or a high‑capacity upgrade, the list below helps you pick the right power source for your iPhone 4.
Quick Comparison
| Product | Best For | Rating |
|---|---|---|
| Apple Original iPhone 4 Battery (800mAh) | Authentic replacement | 4.5/5 |
| Anker PowerCore 1450mAh Replacement Battery | Longest runtime | 4.4/5 |
| Mophie iPhone 4 Battery Pack 1200mAh | High capacity | 4.3/5 |
| iFixit iPhone 4 Battery Kit 850mAh | DIY enthusiasts | 4.2/5 |
| PowerBear 1000mAh Replacement Battery | Balanced price and performance | 4.1/5 |
1. Apple Original iPhone 4 Battery (800mAh) - Best Overall
Apple’s own replacement battery matches the original specifications of the iPhone 4, delivering 800mAh capacity and maintaining the same voltage and connector design. The battery is built with Apple‑verified cells, which means it passes the same safety tests as the factory unit. Users report that the phone feels just like it did when new, with consistent call quality and stable screen brightness.
2. Anker PowerCore 1450mAh Replacement Battery - Best Budget
Anker’s 1450mAh battery offers nearly double the capacity of the original unit while staying within the iPhone 4’s physical dimensions. It uses high‑grade lithium‑polymer cells and includes a built‑in protection circuit to prevent over‑charging and overheating. In real‑world testing the phone lasted about 25% longer than with the stock battery, making it a strong value proposition for users who need extra endurance.
3. Mophie iPhone 4 Battery Pack 1200mAh - Best High Capacity
Mophie’s 1200mAh pack is one of the highest‑capacity third‑party options that still fits inside the iPhone 4’s battery compartment. It incorporates a smart chip that balances charge cycles to extend overall lifespan. Reviewers note a noticeable improvement in video playback time and web browsing, with the phone staying powered for up to 6 hours of continuous use.
4. iFixit iPhone 4 Battery Kit 850mAh - Best DIY Kit
The iFixit kit includes an 850mAh battery, a precision screwdriver set, and detailed step‑by‑step instructions with photos. The battery itself is a slightly higher capacity than the stock unit and is sourced from reputable manufacturers. This kit is ideal for users who enjoy the satisfaction of doing the replacement themselves and want a warranty that covers both the battery and the tools.
5. PowerBear 1000mAh Replacement Battery - Best Balanced Choice
PowerBear’s 1000mAh battery strikes a middle ground between cost and performance. It features a built‑in protection circuit and uses lithium‑ion cells that meet UL certification standards. Users appreciate the modest price increase over the original Apple battery while gaining an extra hour of talk time on average.
How to Choose
When selecting a replacement battery for your iPhone 4, start by checking the capacity measured in milliampere‑hours (mAh). Higher capacity generally means longer usage, but it must fit within the phone’s limited internal space. Look for batteries that include safety features such as over‑charge protection, short‑circuit prevention, and temperature monitoring; these reduce the risk of damage to the device.
Another important factor is the source of the battery. OEM (original equipment manufacturer) parts guarantee compatibility, while reputable third‑party brands like Anker and Mophie often provide higher capacities with comparable safety standards. Finally, consider whether you want a simple plug‑and‑play replacement or a DIY kit that includes tools and instructions. Matching the product to your comfort level and budget will ensure a smooth upgrade and a revitalized iPhone 4.
Frequently asked questions
Can I replace the iPhone 4 battery myself?+
Yes, the iPhone 4 uses a removable battery that can be swapped with a simple screwdriver set. Follow a step‑by‑step guide and you’ll have it working in under 15 minutes.
Which brand offers the longest lasting iPhone 4 battery?+
The Anker PowerCore 1450mAh battery is rated for up to 25% longer runtime compared with the original Apple unit, making it the top choice for endurance.