Review: Mugen extended “fatty battery” for T-Mobile G1


L-R: Mugen G1 back w/battery below; original G1 back and battery

L-R: Mugen G1 back w/battery below; original G1 back and battery

A common complaint with the first Android phone, the T-Mobile G1, is the lousy battery life.  All you have to do is look at the battery and you see how small it is to understand why that is.  It’s only rated at 1150 mAh which explains the battery life challenge.  It’s easy to understand why I was chomping at the bit to take a look at an extended battery for the G1 when the folks from Mugen approached me.

Mugen Power has been making high-capacity batteries for notebooks and phones for years. Their reputation is very good and their batteries always seem to add a lot of life to the device when compared to standard batteries.  The battery for the G1 is no exception. It looks to be very well made and you only have to look at the Mugen battery next to the standard G1 battery to see how much more powerful it is.

The Mugen battery is rated at 2400 mAh, which is more than double the capacity of the original G1 battery.  It comes with a new back for the G1 which is needed to fit over the thicker battery.  The build quality of the Mugen back is very good and it fits the G1 perfectly.  You do lose that Google (s goog) logo on the back of the G1 though.  :)

Replacing the standard battery with the Mugen is straightforward and took only a few seconds.  The instructions require you to charge the new battery for at least 8 hours the first time.  I let it charge overnight, and I’ve been using it ever since.  I haven’t had it long enough to do real benchmarks but I can confidently state it is definitely getting at least twice as long on a charge.  I was finding the G1 to get very low at the end of the day with the original battery and I’m on day 3 of the first charge with the Mugen.

The Mugen G1 battery is $63.95 on their web site, and it’s a good investment if you lament the poor battery life on your G1.



Buyer beware. I bought a 3900mAh battery from Mugen and it was defected. They asked for me too send it back and they would pay for shippinfg it back. Now that they have it they will not respond to emails or refund me the shipping. The only way I got them to refund the price of the battery was to file a dispute with paypal.


I got my Mugen extended battery for G1 from Nakedcellphone on ebay.
This thing is a lifesaver!!!
FYI: They only advertise the bronze version but they can hook you up with black or white/gold back door if you request it.


I know with the extended battery the thickness is increased alot but I was wondering if the G1 will still fit in the sleeve that comes with the phone?

James Kendrick

I have an evaluation Mugen battery on the way for the HTC Advantage. I’m looking forward to seeing this as I’ve been pretty happy with the battery life of the Advantage. I can only imagine how long it would last with a Mugen battery onboard.


I would so do this for my Samsung Rant, but they don’t have it up on their website. Grrrr.


Isn’t there a way to make it less thick, but stretch the battery over the height of the G1.
I’m not walking around with such a thick phone, it would seem suspicious in my pants ;)

I’m more likely to buy a solar recharger.


I have a G1 and “chAmping at the bit” doesn’t begin to describe my eagerness to try out this battery. Good review!


I am so tempted, but it really does make the G1 very bulky and it is not a nice sight. How can the blackberry be so slim – or do they have the same battery problems?

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