The iPhone with the longest battery life isn't the $999 iPhone X (AAPL)

iphone x

If you want the iPhone with the longest battery life, you don't necessarily want the iPhone X, Apple's highest-end iPhone.

Although the $999 iPhone X is clearly Apple's flagship, it doesn't sport flagship battery life.

Instead, look to the less expensive iPhone 8 Plus for Apple's longest-lasting battery. This is largely because Apple can fit a bigger battery into the Plus-sized dimensions of the phone.

Here are Apple's battery stats for the iPhone X:

iPhone X battery

And here's what Apple says you can expect from the iPhone 8 Plus:

iPhone 8 Plus

As you can see, the iPhone 8 Plus manages an extra hour of internet use and video playback, according to Apple's testing. And it retails starting at $799, $200 less than the iPhone X.

That's not to say the iPhone X has bad battery life. There haven't been any independent tests yet, and Apple says it lasts significantly longer than the iPhone 7 while being roughly the same size. And if you're fine covering up Apple's new design, you will be able to get a battery case for it — although maybe not from Apple, which has not announced an iPhone X battery case and didn't respond to questions about it.

So if you're looking for the longest battery life possible, don't simply go out and buy Apple's most expensive and most advanced iPhone. Look to the iPhone 8 Plus, or even the iPhone 7 Plus, which has similar battery life and is a good deal at $669.

iPhone 8 / iPhone 8 Plus