The iPhone 5’s battery life isn’t bad, but it isn’t awesome, either. With careful use, you can make your iPhone’s battery last all day. If you want to work your iPhone hard, however, particularly when you’re traveling or otherwise away from places to recharge the device, you need a battery case.

I’ve looked at many battery cases for the iPhone 5. All of them plug into your iPhone’s Lightning connector, and all of them work basically the same way: You charge the cases up by plugging them into a wall adapter or USB port, and you activate them when you want to start charging up your iPhone’s built-in battery. If your iPhone 5 is inside a battery case and you plug in the case to recharge it, your iPhone recharges first, and only afterward does the case start charging.

The best iPhone battery cases should be easy to toggle on and off, simple to charge, and capable of providing a good indication of how much battery life remains in the case. Oh, and of course, they should provide a lot of extra juice.

On a more subjective scale, I prefer button overlays to cutouts. With the latter design, cases leave holes around the volume buttons, the Sleep/Wake button, and usually the Ring/Silent switch. I find the iPhone’s buttons harder to press through such tiny gaps; I prefer a “surface-level” hardware button that doesn’t require squeezing the tip of my finger into a small space.

Keeping your iPhone in a battery case while traveling may provide an extra benefit, since almost all such cases rely on Micro-USB cables for charging—you may well have other devices (keyboards, speakers) that can share the same charging cable, and replacement Micro-USB cables are far cheaper than Lightning cables.

Regardless of which battery case you choose, a bit of advice: Your iPhone 5 requires more juice to charge the final 20 percent of the way. Turn on your battery case when the iPhone's battery level drops to around 20 percent remaining, and then turn the case off again when your iPhone hits 80 percent. That strategy will maximize how much battery goodness you can squeeze from the case while you’re out and about.

The Mophies

Mophie Juice Pack Plus

Mophie makes excellent battery cases, and sells three models for the iPhone 5: the Juice Pack Helium ($80), the Juice Pack Air ($100), and the Juice Pack Plus ($120). If you’re familiar with Mophie’s battery cases for the iPhone, you should note that Mophie made these names a smidgen confusing. The Helium for the iPhone 5 looks a lot like the Air for the iPhone 4/4S, the Air for the iPhone 5 resembles the Plus for the 4/4S, and the Plus—well, it also looks like the Plus of old.

The Helium offers the least power (1500 mAh), and has button cutouts. The Air (1700 mAh) and the Plus (2100 mAh) both offer button overlays. The Plus adds substantial power without being significantly larger than the Air; unless you really value the slightly smaller size, go with the Plus.

One drawback to the Mophie cases is that their thick bases all require that you use an adapter cable to access the headphone jack. However, each two-piece case is easy to put on and remove.

Plus: 5 mice

Air: 4.5 mice

Helium: 3.5 mice

MyCharge Freedom 2000

The $80 MyCharge Freedom 2000 packs in 2000 mAh of power, which the company says should more than double your iPhone 5’s battery life. The case takes a decidedly different approach from the Mophies. For starters, it’s a single piece, and you “press fit” your iPhone into the case. The little rubbery flap that guards the Micro-USB port on the base feels awfully vulnerable to an accidental tear. You’ll also find a Lightning-connector charging tether, which you pull out from the case’s body and manually plug into your iPhone 5.

 

The left upper edge of the case is carved out to expose the volume buttons and the Ring/Silent switch—I actually prefer this larger kind of cutout to individual-button cutouts. The Sleep/Wake button overlay, on the other hand, is really tough to use: I need to push very hard to make it trigger the button underneath.

I found the tethered Lightning plug to be an odd design choice. When charging, the phone looks dopey, with a tiny cable sticking out of it. Plugging and unplugging the connector feels a bit fussy, since you have so little wiggle room. On the plus side, the design leaves the base of the iPhone 5 entirely exposed, so you can plug in your headphones, or another Lightning cable, with ease (say, to connect your iPhone to your car’s audio system).

This is the case to choose if you want easy access to the bottom ports on your iPhone 5.

3 mice

Lenmar Meridian

 

The $90 Meridian is a two-piece case, similar in design to the collection from Mophie. The case offers 2300 mAh of power, which is a lot, and it fits into a svelte package. Also like the Mophie cases, the Meridian leaves the headphone jack very deeply recessed—but while the Mophie cases ship with a small headphone adapter, the Meridian doesn’t. You’ll be able to squeeze your white iPhone headphones into the plug if your aim is straight and true, but anything thicker will require an adapter that you’ll need to provide yourself.

The case employs cutouts around the buttons. I was unimpressed with how the case’s upper piece fit—near the cutout for the Sleep/Wake button, the case failed to sit snugly against the top of my iPhone 5. Other cases didn’t have that problem.

Still, if you’re after the most milliampere hours possible, the Meridian is worth considering, as it holds that crown among the cases I looked at for this roundup—or at least, among the cases I can recommend.

3 mice

The iBattz cases

iBattz makes the batteries in its cases removable, which is a clever design since it means you can carry more than one backup battery if you’re so inclined.

I looked at the $80 Mojo Hi5 Power Bank Case. (Don't be confused by the iPhone 4 shown on the box—this case is, in fact, made for the iPhone 5.) The Power Bank is designed so that you can keep your iPhone in a slimmer case until you actually need the extra battery power: The package includes a pair of slim plastic hard-shell cases, plus a single 2500-mAh battery that you can snap onto your case-clad iPhone as desired. I understand the appeal here, but if I need to lug around the battery anyway, I’d rather keep it on my phone at all times so that I don’t lose track of the thing.

iBattz Mojo Hi5 Power Bank

Like the Freedom 2000, the Power Bank requires that you charge it with your own Lightning cable. So, when you want to use the battery, you need to connect it to your iPhone with your overly long cable, which looks awkward. I don't get it. (If you want to use a shorter adapter, you can buy one through iBattz separately.)

The two single-piece hard-shell cases look nice, and the setup with the battery snapped onto it looks sharp, too. But with this case option, you’re really toting around a stand-alone charging unit that happens to fit on the back of your iPhone.

I also tried iBattz’s $90 Mojo Refuel Removable Battery Case. To be clear, all of the cases I’m writing about are removable; with the Refuel, iBattz is stressing that the case’s battery is itself removable, and that you can hang on to more than one. This case consists of two pieces: a slim backing battery that connects to the Lightning port (thank goodness!), and a thin, interchangeable frame that pushes down around the front of the iPhone’s edges. I really liked the look with the black battery and the red frame.

iBattz Mojo Refuel Removable Battery Case

The case uses cutouts, which I don’t love, but it does offer that removable battery, true to its name. You can slide off the plastic backing without needing to take the case off your iPhone 5, and swap in a different battery on the fly.

And there’s more. For $20, you can purchase the optional Mojo Refuel Armor Kit, a rugged outer shell that uses the Refuel case underneath. The two-layer armor kit involves a solid piece that snaps onto your iPhone first, with a hard rubbery layer that wraps around it, offering impact protection coupled with the case’s battery-boosting ability. The case uses rubbery flaps that protect the headphone jack, the Ring/Silent switch, and the Micro-USB charging port, along with overlays that protect the buttons. iBattz says that the Armor Kit shields the iPhone from dust, sand, and light splashes of water. If you want the extra battery life and serious iPhone protection, this is the case to get. (You can buy the complete setup for $100.)

Power Bank: 2 mice

Refuel: 3.5 mice

Refuel plus Armor Kit: 4 mice

Belkin Grip Power Battery Case

Belkin's two-piece Grip Power Battery Case

The $100 Belkin Grip Power Battery Case packs in a 2000-mAh battery, and is available in several color pairs. Like the Mojo Refuel, it consists of a main battery portion that plugs into your iPhone 5, and a thin frame that snaps down around the front. The backing plastic on the case feels a little cheap in my hand, but I like the look regardless.

The Grip Power is one of the few battery cases I tested that intentionally protrudes beyond the screen—a design that affords a bit of extra protection if you drop the phone and it lands screen-side down.

The Micro-USB port on the Grip Power is tucked away on the side, which works fine. You’ll find button overlays for the volume and Sleep/Wake controls, and a tight cutout for the Ring/Silent switch. Because it covers the headphone jack, as the Mophies do, the Grip Power ships with a small headphone extension cord.

Instead of a little groove for you to pry the case apart and remove it, a tiny tab sticks out of the right side. This is the case’s best feature—it’s easy to grip, and it makes removal a cinch.

4 mice

PowerSkin Pop’N for iPhone 5

PowerSkin's Pop'N... suction cups and all.

This is an odd case. The $80 Pop’N for iPhone 5 can work as a case, or as a battery add-on to your existing case—that is, assuming your case will stick to the suction cups that cover the surface of the Pop’N.

The Pop’N offers a 2000-mAh battery, and it shows off some interesting design choices: Because it adheres to the back of your iPhone, it doesn’t occlude the sides—all of those buttons remain exposed, as does the headphone jack at the bottom. But the case doesn’t even reach all the way to the top of the iPhone 5; it’s only about as tall as a previous-generation iPhone.

In my tests the suction cups stuck fairly well to the iPhone itself, and to a variety of cases I tested the Pop’N with.

3 mice

Unu DX Protective Series

Unu DX Protective Series

Though it has a cheap plasticky feel reminiscent of the Belkin Grip Power, the $80 Unu DX Protective Series is worth a look. It uses a 2300-mAh battery, and has a two-piece cap-and-base design that functions a lot like the Mophies do. The DX ships with a small headphone extension cord, too.

The case uses button cutouts, including one around the Ring/Silent switch that I actually don’t hate. I often find that such cutouts make the Ring/Silent switch difficult to access; here, however, thanks to the thin cut of the case in the area, accessing the switch isn’t a challenge.

I don’t love the seam that the case makes where the cap and base fit together—it’s too visible. Still, the DX packs a lot of battery power, and it’s easy to put on and take off, so it isn’t a bad option.

3.5 mice

Which one should you buy?

For most people, the Mophie Juice Pack Plus is the best option. If you can’t stand its added weight or thickness, choose the Juice Pack Air instead. If you need rugged protection, the iBattz Refuel case is the way to go; also stick with iBattz if you value hot-swappable batteries foremost. But unless you’re in one of those situations, Mophie still dominates the battery-case market for the iPhone 5.

Your smartphone is a minor miracle, a pocket-sized computer that can fulfill almost every whim. But none of its superpowers matter a bit if it runs out of juice. With removable batteries becoming more and more rare, you've got to take good care of the one you got. Fortunately, it's not to hard keep the lithium-ion powering your everything machine happy if you follow a few simple rules.

Obviously, the first rule for extending your battery life is not using up all your battery life playing candy crush and walking around with Wi-Fi and GPS enabled when you're not using either and really, really need your phone to last that extra hour. But aside from that, there are some basic rules for care and charging, and they're the simplest baseline for a healthy battery.

Top it off

You may vaguely recall hearing something about rechargeable batteries and the ""memory effect."" You know, that if you don't ""teach"" your rechargeable batteries their full potential by taking them from totally full to totally empty, they'll ""forget"" part of their capacity. Well forget all that. Right now. It's wrong.

Battery memory is a real thing, but it applies to nickel-based batteries; your trusty sidekick (literal Sidekick or otherwise) doubtlessly has a lithium-ion battery, and it needs to be treated a little differently. Specifically, it should be topped off whenever you get the chance.

To get the most out of a lithium-ion battery, you should try to keep it north of 50 percent as much as possible. Going from all the way full to all the way empty won't help at all; in fact, it'll do a little damage, and it's even worse if do a full drain on a regular basis. It won't make your battery explode or anything, but it will shorten its lifespan.

But! You don't want to have it charging all the time either; lithium-ion batteries can get overheated. Luckily for you, your charger is smart enough to help with this, and will cut your phone off for a spell once it's full. And to complicate matters a little further your battery doesn't particularly like being all the way full either. In fact, your battery will behave the best if you take it off the charge before it hits 100 percent, and leaving it plugged when it's already full is going to cause a little degradation.

So if you're really particular about optimizing your battery's life, you should try to go from around 40 percent to around 80 percent in one go, and then back down whenever possible. A bunch of tiny charges isn't as bad as going from 100 down to zero all the time, but it's not optimal either.

Keep it cool

It's easy to worry about bad charging habits thanks to the training we've had from old rechargeable batteries, but lithium-ion batteries have a worse enemy: heat. Your smartphone's battery will degrade much much faster when it's hot, regardless of whether it's being used or just sitting around doing nothing.

At an average temperature of 32 degrees fahrenheit, a lithium-ion battery will lose six percent of its maximum capacity per year. At 77 degrees, that number jumps to 20 percent, and at 104 degrees it's a whopping 35. Sure, it's not exactly practical (or sane) to keep your phone in the fridge, but it's worth going out of your way to prevent long stays in hot cars and the like.

Avoid wireless charging

Wireless charging is can be incredibly convenient if your phone can do it, but it's not without its disadvantages. The inductive, wireless chargers out there today have this nasty habit of generating a fair bit of waste heat. And while wasted energy is just a bummer in general, that heat will also toast your battery in the process. That's no bueno. It's a little less convenient, but standard plug-in charging is going to keep your battery in better shape, especially if you're some place warm to begin with.

Never go to zero

Obviously, using your battery is going to make it degrade. But it's going to slowly die even if you just leave that iPad in the closet for a bit. There's a trick to minimizing that inevitable aging though: leave it a little bit of juice.

If you're going to be shelving any lithium-ion battery for a long time, try to leave it with at least 40 percent battery power to tide it over. Lithium-ion batteries don't hemmorage power at 30 percent a month like nickel-metal-hydride batteries do; they'll lose maybe five to ten percent of their charge each month.

And when lithium-ion batteries get too low-like, literally zero percent-they get seriously unstable, and dangerous to charge. To prevent explosion-type disasters if you do try to charge one, lithium-ion batteries have built-in self-destruct circuits that will disable (read: destroy) the battery for good, if it reaches rock bottom. And sure, that'll save you from a face full of battery-acid, but it'll also leave you short one battery.

Don't sweat it too much

It's easy to get protective of your battery, but it's also easy to get lazy. And that's fine, because as long as you're not a complete idiot, you'll be OK. Typically, a lithium-ion battery lasts for three to five years, and chances are you're going to want to swap out your gadgets sometime in that window anyway. The slight damage of a technically bad idea like leaving your phone plugged in all night every night, or using wireless charging, might be worth the convenience.

Still, it's pretty easy to keep your battery reasonably healthy just by avoiding particularly egregious torture like letting your phone discharge from full to zero every single day, or leaving it in a hot car all the time. And the next time you make it back home with power to spare, you'll thank yourself for it.