We went hands-on with Mazzo's PowerDrive Slim, which combines an external battery with a hard drive, to give you extra storage and extra battery life for your iPhone. There's 32GB of storage space for storing files, photos, and videos, plus a 3,000 mAh battery that translates to approximately one full charge for an iPhone 6 Plus.


Files can be transferred to the PowerDrive Slim using the accompanying PowerDrive iOS app, and at the same time, it can charge your iPhone. You'll need to supply a Lightning cable for transferring files and for charging your iPhone from the PowerDrive Slim.

Size wise, the PowerDrive Slim is thicker than an iPhone 6 Plus, but not quite as wide or tall, so it fits easily enough in a pocket. We liked the portability, and we were impressed with the app, especially when it came to the auto backup feature for photos.

The 32GB PowerDrive Slim can be purchased from Amazon for $59.99. Mazzo also sells the device in higher capacities up to 128GB, which will be available for purchase in the near future.

Top Rated Comments

Michael Scrip Avatar
135 months ago


In my opinion 300 is too few. But, at least this company admits that spec. Most companies don't – including the Xiaomi brand recommended above. To put it in perspective, Macs are expected to last 1000 cycles, eneloop rechargeable (although alkaline not lithium) are supposed to last 2,000 cycles. I'm not going to buy something I know I will throw away in <2 years.

You'd only throw it away IF you've burned through all the cycles.

And assuming 300 cycles... you'd have to charge and discharge this battery pack completely, every other day, for it to expire in less than 2 years. Is that even possible?

I'm just trying to imagine a situation where an external battery pack gets used that much.

Maybe once in a blue moon or while camping or something... but not every day or two.

These types of battery packs are typically used after you've depleted your phone's internal battery. And your phone should get through most of the day on its own before requiring additional power.

If you're using an external battery every couple days in addition to your phone's battery... there might be a bigger problem afoot. :)

Oh I get it... more charge cycles are better. But I'm having a hard time imagining how anyone can use 300 complete cycles over 2 years.

Let's say this battery pack was rated for 1000 cycles... do you honestly think it will last over 6 years?

I could see a laptop battery claiming that... but not one of these booster batteries.

I'd love to buy an external battery today and keep it until 2021... but it just seems unlikely.
Score: 1 Votes (Like | Disagree)
Michael Scrip Avatar
135 months ago


It's still a terrible battery and you will simply get less out of your investment.

Less cycles means:
Faster drop in effective capacity AND you get to use that battery for much shorter.

I really don't know why you would be inclined to get this unless you are seriously worried about the storage and battery being one device.

Yeah... isn't that the point of this? Battery and storage?

There are hundreds of regular external battery solutions out there.

But this one includes some storage with it.

And the topic was life cycles. Is 300 too low?

I have one of those Anker lipstick-style batteries... but I don't even know how many life cycles it's supposed to have. I never looked.

I use it sparingly... so even if it only had 300 life cycles it would still take me many years to use them up. I'd probably get a new one anyway before its life is completely used up. Plus I don't believe there's any way to see how many I've used.

What if they claimed 1,000 life cycles for this battery? Would that actually give you 3 times the lifespan? Who knows. You're pretty much taking their word for how many life cycles they have anyway.
Score: 1 Votes (Like | Disagree)

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