The iPhone 7 might be nearly four years old, but as one of the last smartphones Apple made with Touch ID it has remained very popular. 

Running the latest version of iOS and sporting the still-excellent A10 Fusion processor, it has held up particularly well. 

However, one are where you may be feeling some strain is battery life. The iPhone 7 came with just a 1,960mAh battery, while the 7 Plus fared a bit better at 2,900mAh.

While it may have been fine to last a full day when you first bought it, you may be struggling to get more than a couple of hours out of it now. That's where a battery case comes in. 

One of the iPhone 7 battery cases reviewed here claims to be compatible with the iPhones 6, 6s and 7, due to its larger rear camera cutout, but most 6/6s cases fail the camera cutout test.

Many of the products we recommend here are compatible with the later iPhone 8, but you can also check out a separate guide to the Best battery case for iPhone 8 and iPhone 8 Plus.

Apple iPhone 7 Smart Battery Case

Apple iPhone 7 Smart Battery Case

Apple's smart battery cases might not hold up to the company's usual sleek design language, but they are very practical. 

The case has a soft elastomer hinge that makes it super easy to slip the iPhone in and out of the convenient one-piece design. Many battery cases come in two parts, which can sometimes detach and get lost or snap.

You can sync and charge the iPhone 7 and Battery Case at the same time when the phone's in the case. This uses the same Lightning cable you get with the iPhone.

Unusually, the iPhone 7 draws power first from this case, before using its own internal power. Most other battery cases let the phone drain its own battery first, and then use the extra case battery. The case ensures that the iPhone will have 100 percent charge for as long as possible.

There’s no LED battery life indicator on the exterior of the case, although curiously there is one on the interior. Instead battery status is displayed on the iPhone Lock screen and in the Notification Centre. At first this seemed odd, but you get used to it quickly, and is actually a neat idea.

The iPhone 7 Smart Battery Case has a 2,365mAh charge capacity, which is lower than most battery cases but enough for one full recharge, but no more until it gets charged again itself.

At £99/US$99/AU$149 the Apple iPhone 7 Smart Battery Case is not cheap, but if it both protects your precious phone and gives you enough power for the day then it represents good value, and as it's made by Apple you can be sure of its build quality and safety.

Read our full Apple iPhone 7 Smart Battery Case review.

Mophie Juice Pack Air for iPhone 7

Mophie Juice Pack Air

Mophie is the market leader in smartphone battery cases, and it's great that it now has a dedicated case for the Apple iPhone 7 and iPhone 7 Plus – as well as it's Hold Force magnetic solution (see further down this feature).

The Mophie Juice Pack Air for iPhone 7 is compatible with Qi and other popular wireless charging systems, which sets it apart from other battery cases reviewed here. Charge Force technology aligns magnetically with all Mophie Charge Force wireless power accessories (such as the Charging Base £39.95/$39.95). Simply place your Mophie case on any wireless charging base and power is sent to your device directly on contact. 

The wireless charging option is great if you buy one of the optional Mophie charging bases. It adds a level of simplicity to your day by saving you searching for the right cable and getting it into the plug the right way round.

Either wirelessly or wired the phone charges first, followed by the Juice Pack battery. The iPhone 7 model has a battery capacity of 2,525mAh, and the iPhone 7 Plus version 2,420mAh – both enough for a full recharge from a fading battery.

A battery case isn’t just there for charging purposes. It’s just as important that it protects your phone – after all, a fully charged but smashed or damaged phone is about as much use as a dead one. The iPhone 7 Mophie Juice Pack Air features rubberized support pads and raised corners to safeguard the screen from drops and scratches.

The Mophie Juice Pack Air for iPhone 7 looks and feels great. The buttons are nice and responsive.

It does add more bulk to the iPhone than some of the slimmer cases reviewed here. One disappointment is that this case charges via a Micro USB port, and not Apple's Lightning connector – meaning you have to suffer the usual non-reversible Micro USB fumbling, and need an extra cable lying around when you need it (unless you go for the wireless-charging option). It's also a two-part case design, which is not a great hardship but one-piece designs do seem more popular these days. 

Each is available in Black, Gold, Rose Gold, Navy and Red. You can buy it now for just £59.95/US$59.95 for both the iPhone 7 and 7 Plus

Ekrist

Ekrist Battery case for iPhone 8/7/6/6s

A 6000mAh capacity means it should be able to charge both the regular and Plus model at least twice, while LED indicators give a quick overview of how much juice is left. 

As with many battery cases, upon connection to the power your iPhone will be charged first, before the case is juiced up. 

It also boasts a 360-degree scratch guard, meaning it can stand up to the task of everyday wear and tear. 

The standard 4.7in compatibility means it will also fit the iPhone 8, 6 and 6s, but none of the Plus models. 

You can buy it now for £25.90, although it doesn't currently ship to the US.

iPhone 7 battery case buying guide

There are plenty of things to look out for when buying an iPhone 7 battery case. Here are four key areas to keep in mind. 

Power

It's not quite as simple as it sounds but look for a large battery capacity in the case. It needs to be at least 2,000mAh (milliamp hours), but that would just scrape a full recharge, and more likely give you just 80 percent more juice – enough but there's better out there. See dedicated articles on phone battery charging tips and tips to boost iPhone battery life.

Protection

An equally important role of the battery case is to protect your phone from bangs, crashes, drops and bumps. We look at case robustness in all our tests. Also note that while the iPhone 7 is waterproof, most cases are not.

(Also see our round up of the best iPhone 7 and 7 Plus cases).

Design

Look for lightweight and slim battery cases if you value the iPhone's naked statistics. You usually sacrifice some slimness for extra battery capacity.

Charging cable

Try to choose a battery case that uses Apple's Lightning charge and sync cable rather than MicroUSB as that avoids having to keep two different types of cable – one of which (MicroUSB) is fiddly. We also have a round up of the best charging cables if you need a few suggestions.