uNu Ex-Era Modular Battery Case for iPhone 4/4S Review

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One thing I’ve noticed about my iPhone 4 is that the battery drains at a much faster rate than the batteries in my old dumb phones did.  This is especially true now that I keep Bluetooth turned on all the time to keep the iPhone connected to my V-Tech Bluetooth home phone.  There’s nothing worse than being away from a charger and realizing that my battery is almost completely drained, and I’m not always carrying a gear bag with a backup battery in it.  Most cases with backup batteries built in are too clunky to want to leave on the sleek iPhone all the time.  The Ex-Era Modular Battery Case for iPhone 4 / 4S from uNu is the perfect solution; there’s a sleek case that fits on the iPhone most of the time, and a compact battery that you can store in a pocket or a small bag that will power your iPhone when you need it.  I was happy to be given the chance to try the Ex-Era Battery Case when they sent one to The Gadgeteer.

Most photos can be clicked for a larger view.

The Ex-Era case consists of a plastic sledge-shaped back (in matte black or glossy white) that has a 30-pin connector at the bottom.  There’s also a plastic bumper-like side piece that’s available in blue, black, pink, purple, red, white, yellow, or gray.  The bumper has a “soft touch” rubbery coating.

You simply slide the iPhone 4 or 4S onto the 30-pin connector, then snap the colored bumper down over the front of the phone.

The case is called “modular” because there are two backs that can be used with the sledge piece.

The first is a thicker, rounded piece that contains a lithium-polymer 1700mAh battery that uNu promises will double the iPhone’s battery life.  They promise 6 hours of web browsing, 7 hours of video, 5 hours of gaming, 6 hours of talk time, 30 hours of music playback, or 240 hours of standby time extra with this battery.  The battery is good for more than 500 charging cycles.

You can see “keyholes” in the sledge back that are the attachment points for the removable battery.

You can also see two silvery-white lines on the battery.  The topmost one is a silver button, and the bottom line is a cover for a blue LED.  Press the button and the LED lights up to show if the battery is charged.  It also shows charging status.  You charge the battery while this back is attached to the sledge.

You can see the white paper-wrapped battery inside the battery back.  This battery can be popped out and replaced with another battery.  You can keep a set of charged batteries ready to use in the Ex-Era battery back to keep you going through the longest trip.

With the battery back in place, the Ex-Era Case weighs 2.93 ounces and measures 4.85″ X 2.3″ X 0.65″.  This does add considerable weight and bulk to the iPhone.  You don’t have to leave the battery back on all the time, though.  You can slide it off and replace it with the thin, flat back.  With the plain back in place, the case is only 0.45″ thick and weighs only 1.4 ounces.

Here you see the flat back on the uNu Ex-Era case.

Both the flat back and the battery back have a matte, “soft touch” finish.

Here’s the front view of my iPhone 4 wearing the Ex-Era case.  The case is flush with the front of the phone, and it doesn’t provide a lip to keep the front glass lifted off the table if I should lay the phone face down.

The back has a large opening for the back camera and its flash.  I didn’t notice any flash flare using the flat back cover or the battery back.

There are openings for the mute slider and the volume buttons.  These openings are “deep” because of the thickness of the bumper, and it can be a bit difficult to use the buttons.

Here you can better see how recessed the buttons are.  Again, it’s a bit difficult to get a finger in the opening to use the power/sleep button.  You can also see how thick the battery back is in this photo, especially at the opening for the camera.  I was able to plug my headphones in; they have a straight plug, but an angled plug may not work as well.  You can also see the top microphone is uncovered.

The 30-pin connector on the bottom of the iPhone is covered.  You use the microUSB port and provided cable to charge the iPhone and backup battery simultaneously.  The wire grid covers the bottom speaker and bottom microphone, but they both function well through the case.

The other side of the case is plain.

The case also comes with a screen protector and a tiny microfiber cleaning cloth.  The screen protector leaves the home button, the front camera, and the ambient light/proximity sensor uncovered.  I didn’t apply the screen protector.

I charged up the battery back before I put the case on my iPhone.  I left it plugged up for about 4 hours to get a complete charge.  My husband, Butch, gave the Ex-Era case a try.  His phone was run down to 6% before we put the case on with the battery back installed.  We left it overnight, and his iPhone 4 was charged to 97% when he got up.  We thought the backup battery was probably drained at that point, but he left the battery back in place during his work day.

Apparently the battery still had a little juice in it, because his iPhone was still at 90% when he got home after 6:00 pm.  Normally, his battery drops by 25-30% during the day, so it seems the battery was still topping off the iPhone’s battery as he went about his day.

Both Butch and I have the Musubo Retro case on our phone, and we are used to the ribbed texture of the sides that make the iPhone a little easier to keep a hold on.  The Ex-Era case is smooth and is a bit slippery.  To be honest, it’s probably not any more slippery than the iPhone itself.

The Ex-Era case with the battery back is certainly thicker and heavier than the naked iPhone, but it doesn’t feel much different than my Musubo case.  It does feel much lighter and thinner with the flat back piece in place.

If you want a case that offers some protection to the sides and back of your iPhone 4 or 4S, the uNu Ex-Era Modular case fits the bill.  If you want a backup battery that’s small and relatively light and doesn’t take up much room in your pocket or bag, the Ex-Era fits that bill, too.  The Ex-Era is the sleek case that converts into a battery case, only when you need the power.  At about $80, it’s a reasonably-priced accessory that provides protection and power for your iPhone 4 or 4S.


Product Information

  • iPhone 4 or 4S
  • Battery can double iPhone's battery life
  • Battery is used only when you need to charge the iPhone
  • With the flat back in place, the case is pretty thin and light
  • Can replace the battery cell, so you can have multiples charged and ready to use
  • A bit slippery to hold
  • Doesn't have a lip to keep the front glass off the table if you lay it face down

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3 thoughts on “uNu Ex-Era Modular Battery Case for iPhone 4/4S Review”

  1. Gadgeteer Comment Policy - Please read before commenting
  2. Janet would you be able to say if this is thinner than the Mophie Juicepack Air with the battery bit on. Since I’m skipping the iPhone 5 I think I may get one…

  3. @Jake I’ve never had a mophie juice pack air for my iPhone. I went to mophie’s site and found the following measurements: 5.07″X 2.51″ X 0.68″. These values are a bit longer and wider than the Ex-Era case, which I measured to be 4.85″ X 2.3″ X 0.65″. They seem very close in thickness, though.

  4. I ordered the unu ex-era battery ase for iphone 4/4s, and do not know how to assembly the cover with the battery inside to the phone already in the other flat case and the bumper. I am going crazy and can not figure out how to do it.
    Need help, Thanks

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