By July 18, 2010

Mugen extended battery for HTC Desire review

SONY DSC HTC Desire is an excellent phone but most users struggle to get through a day when using the device to its full potential. A large capacity battery is a must for many. But there aren’t that many around. Can Mugen 3200 mAh battery be an answer for the power hungry smartphone?

I should perhaps explain that I’m not a heavy user and I usually get three days on a single charge from the HTC Desire’s standard 1400 mAh battery.

I switch off the phone for the night, I keep bluetooth, GPS and 3G off when not needed. Wi-fi is on perhaps for 30 minutes during a three-day period. A fourth day remains an “option” determined mostly by the length of my phone calls.


You may ask why a person like me would need an extended battery, after all, most people do one day and are pretty happy with that. The answer is I hate to keep an eye on every single thing that may feed on precious mAh which I have to do on the Desire – shutting down Mail services several times a day, Task Killing every application after I use it and keeping display’s auto-off at an annoying minimum. It’s the smartphone equivalent of hypermiling and I don’t like it.

I had an extended battery in my old Palm Treo 680 and I got used to a bumper zone extended batteries offer – comfortable 7 days without worrying about battery related what-ifs.

While getting the extended battery for the Treo was a breeze, getting one for the Desire, well, not so much.

Batteries for the Nexus would work. The back cover, naturally, wouldn’t.

A little googling revealed that Mugen had an extended battery AND a cover in the works so when the package became available, I placed my order on June 23. I have to admit that being an early adopter sucks – rumours, substantiated or not, of oversized capacity claims and fake OEM batteries swarming the Internet just kept on lurking in my subconsciousness.

The battery arrived on July 1 (one week from Hong Kong). Anxiously, I installed it immediately and, as advised, proceeded to charging it (from a computer via a powered Belkin USB hub). About five hours later, it was 100% charged. Or was it?

The thing is that when I looked at the percentage indicator at one point it said 67%. Minutes later, it went to 100%. I put it down to a gadget refreshing and forgot about it. More on that later.

The battery lasted 6 days and 14 hours (158 hours). Which is pretty amazing given the fact that I used the phone in a more extensive way than usually.

Here is the summary:

  • calls: 3 hours 10 minutes (about 10 calls attempted but failed)
  • messages: 50 (sent and received and read)
  • wi-fi: about 40 minutes
  • bluetooth: 3 hours with hands-free (but no calls)
  • 3G: about 10 minutes

The phone was in the Airplane mode for each of the seven nights, totalling circa 50 hours. Also. I turned it off completely once to reboot it.

On the other hand, I was maniacally checking on battery status and thus turning on the screen, using an app to keep count of my calls, I kept track of my texts, I installed few apps and few updates, tweaked some settings… small things that do need their juice.

Things were going well.

On the seventh day, however, a weird thing happened.

Shortly after passing 6 days and 14 hours mark, I checked the battery widget – it said 33% (and 31xx mV). Minutes later I heard a beep and the battery died. Pretty much without warning.

At which point I remember the moment when the charging indicator went quickly from 67% to 100%….

Luckily, I was about 100 meters from home.

I charged the battery again (using the same computer and the same USB hub) and this time the percentage shoot up from 83% to 100% in few minutes. I guess my Desire will die at 17% ..

Overall, the battery performed excellently and as expected – six days and a half makes a big difference in everyday use of the phone. It doesn’t really matter whether you are a heavy or a light user, you should at least double your mileage.

Sudden death of the battery, however, takes that much desired peace of mind away in a bit as it introduces another form of uncertainty.

I’m willing to attribute this erratic behaviour to the fact that the battery was brand new and it needed formatting. I expect it will behave normally after few charges.

I’ll be back with an update.

(Disclaimer: I purchased the battery using my own funds from the Mugen’s online store.)


Back cover asymmetric

The hump on the extended cover is asymmetrical. A bit surprising but it makes perfect sense. Texture of the Mugen cover mimics the original. I could do without 5.0 MEGAPIXELS sign …


How the battery cover fits

The bottom part and the left side of the Mugen cover fit perfectly. The right side, not so much. But tragedy it’s not.


DIY gel case

A clumsily modified gel case. Does the job, though. And it was a free spare, anyway. Still, I’d appreciate a custom case of any variety – food for thought, Mugen?




My battery didn’t last to 17% after the second charge as I predicted. It died at 42% – after 10.5 days of light use.

I proceeded to charge the phone from the mains (the third charge overall) overnight. The phone was turned off (not in the airplane mode, it was turned off completely).

While the phone was charging, I contacted Mugen. They responded quickly with a set of questions about the phone’s firmware version, country of origin and the charging process itself, which I duly answered.

The response came again quickly – this time with the suspected cause of troubles (“I think your battery doesn’t contact with the phone well”) and solution (“Please return failed item to:…. As soon as we receive it we will send you a replacement.”). My concerns about postage costs were “refudiated” by a promise that my expenses would be reimbursed.

At this point I suggested that I kept the battery for a while to charge the phone again to see whether the battery’s performance would improve. The Mugen’s representative agreed.

Now, the reason I wanted to give the battery a chance was that I experienced similar behaviour with my Treo’s extended battery when I charged the phone with radio on. The charge indicator would show any % figure afterward and the phone would just die. It only happened about 5 times and only after I had been using the battery for more than a year.

Back to Desire, though. Now I’m on my fourth charge following the sudden death of the battery at 38% (after 8.5 days). To my surprise, it took only 6 hours to charge the battery in the switched-off phone from zero to 100% – shorter than the first charge from the mains lasted.

If the battery dies prematurely again, I’ll send it back to Mugen.


Review by: Kristian Klima

Posted in: Reviews

About the Author:

More than 20 years in the IT industry. Blogging with a passion and thirst for new technology since 2005.
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