The Air Case is the ultra-thin battery case Apple should have made

I'm in love with an iPhone battery case. Yeah, I still can't believe it either. But hear me out.

There are tons and tons of iPhone battery cases to pick from. Last year, I highlighted the seven best ones for any situation. iPhone battery cases usually forsake form for function. After all, they exist to keep your iPhone powered up, not to make a fashion statement.

SEE ALSO: 7 battery cases for the iPhone 6 to keep you powered in any situation

That's why Mophie's popular Juice Packs are thick and bulky. Tylt's Energi Sliding Power Case and the Boostcase are good compromises since they're two-piece battery cases, but they're still on the big side.

The closest "slim" iPhone battery case is Apple's own Smart Battery Case. While it's not nearly as chunky as some others, the battery bump made the company the butt of a million online jokes. Critics and fans slammed Apple for losing its design chops with such an ugly accessory.

The Air Case by Innoant, and currently crowdfunding on Indiegogo, is quite possibly the best battery case I've ever used that balances thinness and power.

I've been testing this ultra-thin battery case — the world's thinnest according to the company, as it's a hair thinner than the ThinCharge — for the past week and I didn't once feel the urge to take it off.

With the Air Case on my iPhone 6, it only adds an extra 0.15 inch of thickness. That's thinner than some regular iPhone cases. With other battery cases, you're looking at adding two to three times the thickness of the Air Case and some significant height as well.

The Air Case for the iPhone 6 and 6S has a 2,400 milliamp-hour battery (mAh) — the Air Case for the iPhone 6+ and 6S+ has a larger 2,800 mAh battery — inside its super-slim design. The case holds 1.3x a full charge for an iPhone 6.

It's not quite the 2x Innoants advertises on its Indiegogo page, but it was more than adequate for even my heaviest usage days.

The Mophie Juice Pack Air has a higher 2,750 mAh capacity battery and the Tylt Energi Sliding Power Case has an even larger 3,200 mAh battery capable of charging an iPhone 6 about 1.5x and 1.75x. Apple's Smart Battery Case has the smallest battery: 1,877 mAh, or just enough for an extra full charge with very little left over.

I'm not writing off the benefits of battery cases with higher-capacity batteries, but I think if I, a power user, can get through 16-20 hours of heavy iPhone usage with the Air Case as a lifeline, then most people will be able to, too. 

Obviously, if you're Snapchatting (the app is a notorious battery guzzler) orliterally using it non-stop, a larger battery case is more useful and pocket-ability is probably not as high on your checklist. For the very, very active iPhone user, a higher-capacity case is probably called for. But that is, if you'll excuse the pun, an extreme case.

Putting on the Air Case is easy. Pop the metal frame over your iPhone and then slide the slim battery through the frame's rails. That's all there is to it.

There's a button on the back. Press it once and it'll illuminate the LED indicator to its right, letting you see at a glance how much power the battery case has left. Press and hold the button and it'll start charging your iPhone; to disable the charging, press and hold the button once more. 

The metal frame recesses the headphone jack a little but not as much as other battery cases. Apple EarPods will still fit perfectly, but the enclosure around my OnePlus Icon earbuds' jack are just a millimeter to thick. It's something to be mindful of, or just go with Bluetooth headphones.

I don't normally nerd out about iPhone accessories, let alone a battery case. But color me impressed with the Air Case. The case is going for $39 for early backers on Indiegogo, but once those run out, it'll cost $49. It's supposed to come out in July.

Like the company says, the Air Case is the battery case Apple should have created. If I was running Apple, I'd buy Innoants and rebadge this baby as an official Apple product.