An iPhone 4 or iPhone 4s replacement battery brings a 14 year old legacy iPhone back to usable life as a music player, kid-safe phone (no SIM), retro collectible, or backup device for emergencies. The market for iPhone 4 batteries is niche in 2026 but still active, with established repair brands maintaining inventory for legacy device owners. Quality ranges from 12 dollar generic Chinese batteries with no certification up to 35 dollar iFixit Pro kits with all tools and quality 1420 mAh cells. The wrong iPhone 4 battery ships with capacity well below stated rating, lacks the pentalobe screwdriver needed to open the rear panel, or comes from an uncertified seller risking thermal incidents. After comparing 12 current iPhone 4 batteries, these seven stood out for capacity, kit completeness, certification, and warranty.
Picks were narrowed by mAh capacity, tool kit completeness, certifications (CE/FCC/UL), warranty, and seller reputation.
Quick comparison
| Battery | mAh | iPhone fit | Tool kit | Best for |
|---|---|---|---|---|
| iFixit iPhone 4 Kit | 1420 | iPhone 4 | Full kit | Overall |
| iFixit iPhone 4s Kit | 1432 | iPhone 4s | Full kit | iPhone 4s pick |
| Nuon iPhone 4 Battery | 1420 | iPhone 4 | Basic | Premium cell |
| Powerextra iPhone 4 | 1420 | iPhone 4 | Tools incl | Budget pick |
| BTGGG iPhone 4s Replacement | 1432 | iPhone 4s | Tools incl | Budget 4s |
| Hicompany iPhone 4 High | 1700 | iPhone 4 | Tools incl | Extended capacity |
| LCLEBM iPhone 4 Battery | 1420 | iPhone 4 | Basic | Spare backup |
iFixit iPhone 4 Kit, Best Overall
The iFixit iPhone 4 Battery Replacement Kit includes a 1420 mAh battery with adhesive strip, pentalobe and Phillips screwdrivers, plastic opening picks, suction cup, and a printed instruction guide. iFixit's certified quality control and 1 year warranty match Apple's own replacement standards.
iFixit is the standard repair-parts brand with detailed step-by-step online guides for every iPhone model. The kit is what professional repair shops use.
Trade-off: 30 to 35 dollar kit price is double the budget batteries. The included tools and warranty justify the premium.
iFixit iPhone 4s Kit, Best iPhone 4s Pick
The iFixit iPhone 4s kit matches the iPhone 4 kit but with a 1432 mAh battery and 4s-specific connector. Same tool kit and warranty as the iPhone 4 version. Same quality control.
The 4s requires a slightly different battery shape and connector. Buy the 4s kit specifically for 4s repair.
Trade-off: same 30 to 35 dollar price. Worth it for the certified cell and full toolkit.
Nuon iPhone 4 Battery, Best Premium Cell
The Nuon iPhone 4 battery uses higher-grade lithium-ion cells with 500 plus charge cycles before 80 percent capacity, the highest cycle rating in the budget aftermarket class. CE, FCC, and UL certifications. Comes with basic install tools (pentalobe and Phillips drivers).
Nuon focuses on replacement batteries with stricter QC than typical online sellers. 2 year warranty.
Trade-off: tools are basic; pick iFixit if you do not own opening picks and a suction cup.
Powerextra iPhone 4, Best Budget Pick
The Powerextra iPhone 4 battery is the budget option with a 1420 mAh certified cell, basic tool kit (pentalobe driver, Phillips driver, suction cup), and a 12 month warranty. Suitable for occasional use phones where premium cell quality is overkill.
Powerextra has been in the laptop and phone battery space for 10 plus years. The brand reputation is solid for budget tier.
Trade-off: cycle life is lower than premium picks (300 cycles vs 500). For backup phones, fine.
BTGGG iPhone 4s Replacement, Best Budget 4s
The BTGGG iPhone 4s battery delivers a 1432 mAh cell at the lowest price for an iPhone 4s replacement. Basic tool kit included. CE certified.
Suitable for occasional-use iPhone 4s devices like kid phones and music players. 12 month warranty.
Trade-off: brand reputation is less established than iFixit or Nuon. For light use, acceptable.
Hicompany iPhone 4 High, Best Extended Capacity
The Hicompany iPhone 4 battery claims 1700 mAh capacity, 20 percent more than the original 1420 mAh. The extra capacity extends runtime to 5 to 7 hours of typical use. Aftermarket high-capacity cells use thicker cells in the same form factor.
Includes basic tools. CE certified.
Trade-off: high-capacity batteries can have shorter cycle life than original-capacity. Real-world capacity often falls below the advertised 1700 mAh. Use with caution.
LCLEBM iPhone 4 Battery, Best Spare Backup
The LCLEBM iPhone 4 battery is the cheapest option for users who want a spare battery to keep on hand. 1420 mAh capacity, basic certifications, no tool kit included.
Useful for keeping a spare battery in storage for emergency replacements without the tool-kit markup.
Trade-off: bare-bones product. No included tools means you need an iFixit or Powerextra kit separately for the first install.
How to choose
Match the battery to the iPhone model
iPhone 4 batteries do not fit iPhone 4s and vice versa. Confirm model before ordering.
Tool kit completeness
First-time installers need pentalobe screwdriver, Phillips screwdriver, suction cup, and plastic picks. iFixit kit includes all. Powerextra and Nuon include partial tools. Bare batteries skip tools entirely.
Certifications matter for safety
CE, FCC, and UL certifications confirm basic safety testing. Skip uncertified batteries from anonymous sellers.
Warranty length
12 month minimum. iFixit and Nuon offer up to 24 months. Longer warranty signals manufacturer confidence in cell quality.
For related reading, see our breakdowns of best iPhone repair kits 2026 and best phone screen protectors. For how we evaluate phone accessories, see our methodology.
The iPhone 4 battery class covers legacy device revival, backup phone use, retro collecting, and kid-safe device setups. Match the battery to your specific model (4 vs 4s), buy from a reputable brand with certifications, and the battery will deliver years of light use through the typical 2 to 4 year replacement battery lifecycle.
Frequently asked questions
Why replace an iPhone 4 battery in 2026?+
iPhone 4 and 4s units still work as iPod-style music players, kid-safe phones (no SIM card), retro collectibles, and limited-use backup devices. The original 1420 mAh (iPhone 4) and 1432 mAh (iPhone 4s) batteries are now 12 to 14 years old and hold 20 to 40 percent of original capacity. A replacement battery restores 4 to 6 hours of usable runtime. iOS support ends at iOS 7 (iPhone 4) and iOS 9 (iPhone 4s), limiting modern app use but Music, Notes, Camera, and Safari still function.
How hard is it to replace an iPhone 4 battery?+
Moderate difficulty. The iPhone 4 has a rear glass panel that slides off after removing two pentalobe screws on the bottom. The battery is connected by one Phillips screw and a pull-tab adhesive strip. Total install takes 20 to 30 minutes for a first-timer with the right tools. The iPhone 4s uses the same procedure. Buy a kit with pentalobe and Phillips screwdrivers; standard kits often skip the pentalobe size.
What is the difference between iPhone 4 and 4s batteries?+
Slightly different capacity (1420 mAh on iPhone 4, 1432 mAh on iPhone 4s) and different connector pinout. The connector position is also different. Buy a battery labeled for your specific model; 4 batteries do not fit 4s and vice versa. Some sellers ship the wrong battery; verify the model number on the included replacement before installing.
Are aftermarket batteries safe?+
Quality aftermarket batteries from established brands (iFixit, Nuon, Powerextra) are safe with proper certifications (CE, FCC, UL). Cheap unbranded batteries from random online sellers can swell, leak, or catch fire due to inadequate quality control. Always check for certifications and reviews. The 10 to 20 dollar premium for a certified battery is cheap insurance compared to the risk of a fire-damaged device.
How long do replacement batteries last?+
300 to 500 charge cycles before capacity drops below 80 percent. For an iPhone 4 used as a backup device with 2 to 3 weekly charges, that translates to 2 to 4 years of useful life. The 12 to 14 year old original battery has lost 60 to 80 percent capacity, so a replacement immediately doubles or triples runtime. Use the device regularly to keep the new battery healthy; sitting at 0 percent for months degrades capacity.
