Earlier this week, I walked through a great collection of iPad, iPhone, and Mac products that I’d strongly recommend. Today, I’m here to help you choose an excellent spare battery for any portable Apple device. You can trust me because I’ve been testing Apple batteries for over a decade, conducting hours-long tests to learn how each new Apple device consumes power, and how quickly each battery replenishes a given device. If you want to learn more about why I’m recommending the specific batteries below, I discuss key factors worth considering at the bottom of this guide.

Top iPhone Batteries

There are two types of spare batteries you can choose for an iPhone: battery cases or battery packs. Battery cases are by far the most popular option, since you don’t have to carry a separate box and Lightning cable around everywhere you go. There are currently no major-manufacturer* iPhone 6 or iPhone 6 Plus battery cases on the market – that will change next month – but you have plenty of options for the iPhone 5/5s. By comparison, USB battery packs almost always offer more power for the dollar, and work with multiple devices, if you’re willing to deal with the extra size and supply a USB to Lightning cable. If you have an iPhone 6 or iPhone 6 Plus, a battery pack is your best choice right now.

If you need a waterproof battery case, we’d strongly recommend the iBattz Mojo Refuel Aqua ($130). Like offGRID Pro, it uses affordable swappable batteries – only one 2200mAh cell is packed in for a full recharge — but you also get IPX8 waterproof submersibility, with anti-shock and anti-dust protection. There’s also a Touch ID-compatible protector for the iPhone 5s Home Button. Users looking for a combination of ruggedization and power will be hard-pressed to find a better choice than this.

Last but not least, Mophie’s Space Pack ($150/$180) simultaneously adds a 1700mAh battery and your choice of 16 or 32GB of extra media storage space to your iPhone 5/5s, all in the same basic size as a typical Mophie Juice Pack case. Space Pack gives you a way to keep older capacity-crunched iPhones running for another year or two, and it’s easier to fit in a pocket than an iPhone 6 Plus.

What About iPhone 6/iPhone 6 Plus?

Right now, our top pick for iPhone 6 and iPhone 6 Plus users would be a device-agnostic USB battery pack such as Just Mobile’s Gum++. Small enough to toss in a pocket, Gum++ packs 6000mAh of power, enough to recharge the iPhone 6 Plus at least 1.5 times, and the iPhone 6 2.5 times. It’s made from resilient ABS plastic and has USB port fast enough to refuel any iPhone at its peak speed. Kanex’s GoPower 11000mAh ($70, shown at the top of this article) offers even more power for the same price, and includes an iPhone-holding tray, though its USB ports are slower. Another option called PoP’n 2 from PowerSkin (not shown) is a 4000mAh battery pack that suction cups onto the back of your iPhone 6 or 6 Plus, connecting with an integrated Lightning plug. The $70 price tag is really steep for that energy capacity, but it’s fairly slender and includes that Lightning connector, so some people may like it.

Update: Readers have pointed out that several small companies are selling early iPhone 6-sized battery cases: i-Blason’s $60, 3200mAh case, Trianium’s $60, 3100mAh case called Atomic S, and iPM’s $33-$60 Powerslider 3200mAh case. Trianium’s case is getting the highest customer ratings, but all three are receiving at least occasional reports of defects or otherwise iffy performance. If you’re looking for an iPhone 6-specific battery case, waiting until CES in January to see options from well-established manufacturers would be a good idea.

Top iPad Batteries

iPads require much higher-capacity batteries than iPhones. The iPad mini’s battery is around twice as large as the iPhone 6 Plus’s, and three times as large as the iPhone 6’s. That means an iPad external battery pack will need 2-3 times as much power just to restore the same 100% capacity. If you don’t need a full iPad recharge, you can get away with carrying around a smaller cell.

A really great compromise option for iPad users is uNu’s Ultrapak Tour ($100). Sleeker and smaller than the PowerPak Ultra, it has a 10,000mAh cell inside and can recharge itself with an included wall adapter in only 1.5 hours — miraculously fast. There’s even a screen on the top to show you the current power remaining, and how long it will take to recharge. Two outputs let you charge an iPad and iPhone at the same time.

Top MacBook Batteries

Apple has all but killed the external MacBook charger market by using patented MagSafe connectors, preventing developers from selling third-party MagSafe-compatible power accessories. But two companies have come up with viable workarounds — they’re big because they need to refuel big laptop batteries, but if you need the extra power, they’re the only options around.

Sanho’s HyperJuice 1.5 ($259) and HyperJuice 2 ($299) are metal-clad batteries with 27,000mAh of power — enough to fully recharge any MacBook Air or MacBook Pro up to 15″ in size, with at least a little power left to spare. Each HyperJuice unit can also supply power to two iPads (or iPhones) at the same time as your MacBook; the 2 model has a fancier power remaining display, but less positive user ratings. The only hitch is that you’ll need a $150 Magic Box modified MagSafe Adapter to connect your MacBook to it.

Choosing A Great Battery

I’ve tested hundreds of batteries, so when I recommend a battery, it’s passed a four-point test focused on quality, capacity, speed, and price — typically in that order. If you think you’ve found another battery that’s worth considering, run through these steps to see how it matches up with our picks.

Quality: A battery should come from a reputable manufacturer with a track record of producing reliable products, and willingness to offer hassle-free replacements in the event of a problem. Good quality batteries tend to last for two or so years.

Capacity: An iPhone battery should generally offer enough capacity to perform at least one full iPhone recharge, while an iPad battery should be able to recharge at least half – preferably more – of a tablet.

Speed: Any iPad battery should be capable of actual “full iPad recharging speed” 2.1-Amp or 2.4-Amp output. Pre-2014 iPhone batteries should be capable of at least 1-Amp speeds, full speed for older iPhones; newer ones ideally would offer 2.1-Amp output. iPad batteries should ideally be able to recharge from their own wall adapters or iPad wall adapters at 2.1-Amp or faster speeds. You’d be amazed at how many companies overstate the speeds of their batteries.

Price: The battery market is ultra-competitive right now, and many battery packs are being sold at too good to be true prices. Based on a lot of past experience, I wouldn’t recommend taking a risk on the very cheapest batteries, as they tend to fail early and I’ve had quite a few of them physically expand/bulge over time. A great price is really dependent on the battery’s quality, capacity, and speed.

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