When users take the specifications of an MP3 player into consideration, one very important factor most take into account is the rated battery life. However, as many are aware, the battery life stated is generally the runtime from a full charge in ideal conditions, such as when the player is left playing without any sound enhancements (EQ, bass-boost, etc.), volume set to a moderate level, all music is 128kbps MP3, backlit display goes out within a few seconds and so on. However, according to tests conducted by CNET, they found that while many players met or exceeded their claims, one feature that has a drastic affect on battery life is the infamous DRM.
When it comes to the Creative Zen Vision:M’s 14-hour claim, CNET got about 16 hours of playback time with MP3s from a full charge, which was a nice surprise. However, when they tried playing WMA 10 DRM crippled subscription tracks on it, they only got just over 12 hours; a loss of almost 4 hours (~25%) of playback time due to the battery-hungry DRM. CNET found similar results with other players with WMA DRM drastically reducing battery life by up to around 20%. Apple’s FairPlay DRM seems to have less of an effect with battery life being reduced by around 8% when compared with MP3 playback.
Those who belong to subscription services such as Napster or Rhapsody have it worse. Music rented from these services arrive in the WMA DRM 10 format, and it takes extra processing power to ensure that the licenses making the tracks work are still valid and match up to the device itself. Heavy DRM not only slows down an MP3 player but also sucks the very life out of them. Take, for instance, the critically acclaimed Creative Zen Vision:M, with a rated battery life of up to 14 hours for audio and 4 hours for video. CNET tested it at nearly 16 hours, with MP3s–impressive indeed. Upon playing back only WMA subscription tracks, the Vision:M scored at just more than 12 hours. That’s a loss of almost 4 hours, and you haven’t even turned the backlight on yet.
We found similar discrepancies with other PlaysForSure players. The Archos Gmini 402 Camcorder maxed out at 11 hours, but with DRM tracks, it played for less than 9 hours. The iRiver U10, with an astounding life of about 32 hours, came in at about 27 hours playing subscription tracks. Even the iPod, playing back only FairPlay AAC tracks, underperformed MP3s by about 8 percent. What I’m saying is that while battery life may not be a critical issue today, as it was when one of the original hard drive players–the Creative Nomad Jukebox–lasted a pathetic 4 hours running on four AA nickel-metal-hydride rechargeables (and much worse on alkalines), the industry needs to include battery specs for DRM audio tracks or the tracks we’re buying or subscribing. Yet, here’s another reason why we should still be ripping our music in MP3: better battery life, the most obvious reason being universal device compatibility.
The full article can be
When it comes to maximising battery life in a portable MP3 player, this is a clear sign that one should avoid playing DRM protected music if at all possible and also another good reason to get the music converted into a more battery-friendly format. While 2 to 4 hours may not seem a lot to some people, this can be the difference between listening to music to the end of a lengthy journey or getting left in silence a couple of hours before the journey is complete.
With the shorter battery life caused by DRM, this means that consumers have to recharge their battery more often, which in turn results in a shorter overall battery life before it needs replacement. Finally, while most MP3 players now have a rechargeable battery, for those who still use disposable AA/AAA type batteries and listen to copy-protected music, not only does DRM cut their listening time, but it also costs them more in replacing batteries, not to mention more battery waste building up in landfills (if not recycled).
Source: c|net News – MP3 Insider