SiGN iPhone 12 battery kit
(7 reviews)
Replacement battery for the iPhone 12 and 12 Pro. Restore your device's original runtime when the battery gets tired.
Characteristics
- Capacity: 2815 mAh
- Compatibility: iPhone 12
- Type: Lithium-ion
- Use: Kit with fitting tools
- Original runtime restored, iPhone 12
Detailed overview: SiGN iPhone 12 battery kit
This 2815 mAh replacement battery restores the iPhone 12's original capacity. It is the smallest of the four generations we cover, and the only one that goes backwards on the one before it.
The kit is complete: the battery, the disassembly tools (screwdriver, spudger, pick) and the adhesive strips for reassembly. Nothing else to order, beyond a little patience and a clear workspace.
There is a reason for that reduced capacity: with the 12, Apple moved to a 7.4 mm chassis against 8.3 mm on the 11. The phone got thinner, the battery lost close to 300 mAh. In practice the iPhone 12 therefore reaches the point where runtime becomes a nuisance sooner: it is often on this model that owners consider a replacement earliest.
The phone itself tells you when to act: Settings > Battery > Battery Health shows the remaining maximum capacity as a percentage. Below 80 %, runtime drops off sharply and iOS eventually displays a service message.
The same kit exists for the other generations: iPhone 11 battery kit, iPhone 13 battery kit and iPhone 14 battery kit. For a newer model, see our batteries for iPhone 15 battery and iPhone 16 battery.
Frequently asked questions: SiGN iPhone 12 battery kit
The marker is in Settings > Battery > Battery Health: below 80 % maximum capacity, runtime drops off. Starting from only 2815 mAh, the iPhone 12 forgives that loss less readily than a better served model, and the annoyance shows up before the threshold is even reached.
It is the price of thinness. The 12 is 7.4 mm thick against 8.3 mm for the 11, and its battery went from 3110 to 2815 mAh. Apple offset this with a more frugal processor, but the energy reserve really is smaller.
This kit is £23.08, the cheapest of the four generations we offer, tools and adhesives included. Going through a repair shop adds labour to that figure.
Stop charging the device immediately and do not press on the screen, which a swollen battery pushes from the inside. Never pierce or bend a deformed lithium cell, and hand it in at a collection point for batteries and accumulators.
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Published on 10/07/2026, updated on 14/08/2026