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Mugen Power 6400mAh Extended Battery for Samsung Galaxy Note II Quick Review

By Anton D. Nagy April 29, 2013, 5:25 am

When it comes to battery life we’re all n00bs! And you know what? You shouldn’t necessarily have to be a power user just to get a solid day out of your phone. This is what phone manufacturers don’t seem to understand (or they understand it perfectly but are much more interested in selling their products than delivering us, users, what we need).

There’s a reason I have officially designated the Samsung Galaxy Note II, and its 11.78Wh (3,100mAh) battery, to be my “official show-covering” phone. Actually, as I think about it, the Pocketnow team’s majority uses Samsung’s phablet while covering events. That is, in big part, due to the fact that it gives you solid performance on the battery side.


However, while covering this year’s MWC, I quickly realized that even the Note II can’t put up with all the stress of a show (leaving the hotel at 5a, returning at 2a the next day, and being abused all the time in-between). However, we’re now talking about almost 24 hour battery life and, while we’re definitely a minuscule and surely ignorable market, there has to be a solution for those like us. If not stock, then after-market.

mugen power 6400mah extended battery

Whether you’re covering shows and events, driving all day and using the Note II as your personal navigation solution, you’re out hiking, you’re a heavy user, or don’t have access to a charger until the next day, this is something you should consider.

In the box

The package contains your extended battery and a battery cover for your Note II. You will definitely need this because your stock battery cover will no longer be able to snap back in place. The Mugen Power battery is twice as thick as the stock juice pack.

You’ll notice that there’s no charger included. That’s because Mugen Power encourages you to use the stock charger that came with your Samsung Galaxy Note II. It outputs 5.0V and 2.0A, fully charging the Mugen Power battery, from flat to 100%, in little less than 12 hours.


On the back of the battery cover there’s a metal strip which you can extend and use as a kick-stand to prop your device up when you’re watching movies, picture slideshows, or listening to music.

On the inside, Mugen Power has built in an NFC antenna so that you don’t lose your scanning and file sharing capabilities once you install the new battery and its cover.


The Mugen Power extended battery for the Samsung Galaxy Note II is rated at 6,400mAh (24.32Wh). That’s more than double the size of the stock battery that comes bundled with Samsung’s giant S-Pen-enabled phone.


However, that battery capacity (and the extra mileage it adds to your smartphone) comes at a cost. While the bundled battery pack measures 6.4mm in thickness, the Mugen Power extended battery is 12mm thick. How does that translate to your phone? Your regular, stock, Samsung Galaxy Note II measures 9.4mm at the middle; slap on the Mugen Power bundled battery cover after inserting the battery and you’re at 18.4mm. That’s a thick phone!

Weight is also something you have to consider. Samsung’s battery weighs about 55 grams while Mugen Power’s weighs 112 grams. The Note II, out of the box, with its bundled battery, weighs 181 grams; equip it with the Mugen Power extended battery plus cover and you’ll carry around a 252 gram heavy device.


Build quality

The Mugen Power battery’s back cover is solid, and feels sturdy. The plastic used is not (or feels not) as high quality as Samsung’s stock battery cover and the metal kick-stand flap on the back will get scratched really easily as the phone sits on it all the time when placed down.

The black version of the battery cover is shiny and sells the impression of Samsung’s hyperglaze while the white one which we are reviewing here is matte with a slight texture on the back.


The cutouts are a perfect fit so you don’t have to worry about the camera, flash, speaker, or even the S-Pen. Everything snaps nicely in place. However, we noticed occasional squeaking sounds which we don’t necessarily like.

Battery life

In our review, we found the 3,100mAh stock battery inside the Samsung Galaxy Note II to offer a full day with moderate-to-heavy use. Of course, “moderate-to-heavy” use, like any smartphone usage, differs from person to person. However, the generally accepted idea is that you’ll be fine for a day in most cases carrying the Note II.


Once you pop in the Mugen Power extended battery things start to change. You’ll first be surprised to see that your battery icon is still showing a fully charged battery after a couple of hours of usage; that’s when you go into the settings and double check. While you’re there, you’ll most probably enable the battery percentage display in the status bar and you’ll love how slowly it will start decreasing.

Our daily usage, while reviewing this accessory, wasn’t at all different from the way we use phones that we review. That means having multiple email accounts set up with push enabled, various social media applications, GPS navigation or mapping, heavy WiFi and data-based browsing, weather apps and widgets, streaming music from Spotify, YouTube video playback, plus the regular daily five-to-ten calls and up to five text messages in addition to ten-to-fifteen emails sent (and more than 50 being received).

Under those circumstances, just before our Galaxy Note II (finally) died, the system reported a battery life of 4 days 16 hours 36 minutes and some spare seconds. Screen-on time reported was 6 hours 16 minutes.


Note: On our first run, with the exact similar usage conditions, we only got 4 days and 9 hours while the second run improved to 4 days and 13 hours. Batteries tend to improve over the first couple of cycles after which they start to constantly deteriorate.

On the extreme end of things, while constantly using the phone throughout the day, we got close to 17 hours of battery life out of which the screen was on for over 14 hours. Not bad!



+ solid performance
+ included battery cover
+ built-in kick-stand
+ built-in NFC antenna


– heavy
– thick
– occasionally squeaking
– somewhat expensive
– kick-stand on the back easily gets scratched

Pricing and availability

You can get the Mugen Power extended battery for the Samsung Galaxy Note II directly from the manufacturer. It will set you back $99.50 and it comes in white and grey color options to match your Note II’s accent. Shipping is free.


The Mugen Power extended battery for the Samsung Galaxy Note II is an excellent answer for those who really need solution that will offer a longer battery life. Whether you’re on a (business) trip, hiking, driving or you simply don’t mind the added bulk and you want to have extreme battery life, this can be one of the resolutions for you.


It will come in very handy when I’ll be abroad, sitting on the beach, this summer, as well as when I’ll be covering IFA in September. However, aside from the four-to-five times per year when I’ll use it, it will mostly sit in a drawer at around %40 charge for preservation. It is simply a tad too bulky and inconvenient to carry (for me, personally), as my daily solution, when I can easily charge my phone overnight and I’m lighter on using it during my regular days.

Still, it is good to have it handy and it is definitely a relief knowing that it’s there, if and when you need it, to make your life charger-free for at least three days.

Update: Mugen Power has reached out to let us know that they replace back covers free of charge.


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