Apple doesn't make a battery case for any iPhone 12 model, unfortunately, and you can't just use a battery case from an any older iPhone — they just won't fit. So if you want battery case so your new iPhone 12 gets even better battery life, you have to buy new one.
When shopping for a battery case, there are a few things you want to consider.
• You want it to have a decent battery capacity; all batteries are different, but a 5,000mAh battery capacity will give your iPhone 12, depending on the model, about an extra 70 percent of juice.
• You want it to support wireless charging so you don't have to rely on a Lightning cable.
• You want it to be small enough that it doesn't make your iPhone too big to fit in your pocket.
The following battery cases check all those boxes. There are currently no battery cases that are fully compatible with MagSafe, but that seems like it will inevitably change in the near future.
Newdery Battery Case
This is 4,800mAh battery case that is compatible with most Qi-wireless chargers. This means you can place it on a Qi-wireless charger and the case and the iPhone 12 will charge simultaneously.
Alpatronix Battery Case
This Alpatronix battery case has a 5,000mAh capacity and supports wireless charging. When placed on the charging pad, the case is smart enough to fully charge the smartphone first before recharging itself. Additionally, the case is made of soft-yet-protective rubber that's easy to slip on and off.
Mophie Juice Pack Connect
The Juice Pack Connect isn't a battery case, but rather a 5,000mAh portable battery that locks onto the back of your iPhone (via an anchor) and wirelessly charges it. It's essentially a modular alternative to having the battery built directly into the smartphone case. You can also buy additional Juice Pack Connects that you can swap in-and-out in case you're going to be away from a power source for a long stretch.
Zerolemon Battery Case
This is another solid option for anybody looking for a battery case. It has 5,000mAh capacity battery and supports wireless charging. The thing that makes this battery case different from the others is its unique AirCusion corners, which help with shock absorption and drop resistance.