Sansa® Clip | Sansa® Clip+

[niko_sama]

Taken from my battery test thread:  http://forums.sandisk.com/sansa/board/message?board.id=clip&message.id=14428

Being curious how long my Clip's battery lasts while playing certain bitrate songs, I started conducting tests.   Testing details are at the end of this post.

The results:   I will update as I complete more tests.  Test Results in Hours Minutes Seconds  HH:MMS

 

Battery Recharging Test Summery: - Charge times from a completely dead battery.

Charging Silver Clip 4GR1:

   Charging from Desktop PC USB:  Test1:  03:39:00    Test2:  03:45:00
   Charging from AC adapter:      Test1:  02:20:00    Test2:

Charging Black Clip 8GR2:

   Charging from Desktop PC USB:  Test1:  02:40:00   Test2:  02:30:00  * charged faster than Silver same USB port*
   Charging from AC adapter:      Test1:  02:16:00   Test2:  02:24:00

Do headphones make a significant impact on battery life?

  Black 8GR2 playing Flac Level8 encoded album at 1/2 Volume

  Standard Sansa Earphones       xx:xx:xx
  Skull Candy FMJ 9mm in-ear     07:46:00
  Sennheiser HD-595              07:40:00
  No headphone - Zero 0 Vol      07:45:00

Playing Time - Comparing the Silver 4GR1 vs.. Black 8GR2:  1/4 Volume

  Silver Flac Lvl8            : 09:02:00  * Silver wins lasting an hour longer than the Black 8GR2 *
  Black  Flac Lvl8            : 07:46:00    I don't understand why???  I'm going to retest again

  Silver Flac Lvl0            : 08:59:00  * Silver wins lasting an hour longer than the Black 8GR2 *
  Black  Flac Lvl0            :~07:50:00    Died between two checks - this is an approximate guess +/- 10 min

  Silver Ogg q8.5 ~256k       :           * Going to retest - Silver died while I was away *
  Black  Ogg q8.5 ~256k       : 08:05:00  * Black was still playing so it wins but not sure by what *

  Silver Ogg q5 ~151k         : 10:15:00
  Black  Ogg q5 ~151k         : 12:12:00  * Black 8GR2 lasted 2 hours longer than the Silver 4GR1*

  Silver MP3 v0 ~252k VBR     : 15:07:00  * Appears ARM clocking to be same as that of v2        *
  Black  MP3 v0 ~252k VBR     : 17:18:00  * Black 8GR2 lasted 2 hours longer than the Silver 4GR1*

  Silver MP3 v2 ~190k VBR     : 15:09:00  * Appears ARM clocking to be same as that of v0        *
  Black  MP3 v2 ~190k VBR     : 17:22:00  * Black 8GR2 lasted 2 hours longer than the Silver 4GR1*

  Silver MP3 v6 ~128k VBR     : 17:40:00
  Black  MP3 v6 ~128k VBR     : 20:47:00  * Amazing.  lasted 3 hours longer than the Silver 4GR1*
 

Playing Time - Comparing Various Encoding Options:

Silver 4GR1: Standard Sansa Earphones

   Flac Level8        :  1/2 Vol = 09:02:00    1/4 Vol = 09:15:00

   Ogg q5 ~151k VBR   :  1/2 Vol = 10:03:00    1/4 Vol = 10:15:00
   MP3 128k CBR       :  1/2 Vol = 17:20:00

   MP3 v6 ~128k VBR   :  1/4 Vol = 17:40:00

Black  8GR2:  Skull Candy FMJ's

   Flac Level8        :  1/2 Vol = 07:46:00

Black  8GR2:  Standard Sansa Earphones

   Ogg q5 ~151k VBR   :  1/4 Vol = 12:12:00

   MP3 v6 ~128k VBR   :  1/4 Vol = 20:47:00

   MP3 v2 ~190k VBR   :  1/4 Vol = 17:18:00

Playing time vs.. Volume level?

  Black 8GR2 - Flac Level 8 encode

  1/2 Vol - Sennheiser HD-595  07:40:00
    0 Vol - No headphones      07:45:00
  1/4 Vol - Standard phones

***********************************************************************

What effects the battery life of the Sansa Clip?

  Processor:   Arm CPU clock speed

  Amplifier:   Volume level?

  Display:     OLED display with adjustable Brightness - not a factor in these tests -
                 display not on frequent enough to be measurable.

  Music:       Codec and Encoding Bitrate affects Arm CPU clock speed,
                 Type of? Easy listening vs.. HardCore? Power required for amp to reproduce the waveform?

  Headphones: Impedance of headphones?

Hardware: Both clips were formatted, reset to factory settings and loaded with the same test files.  EQ on Normal

  Silver 4 gig Revision 1 Clip  Firmware version: 01.01.30a
  Black  8 gig Revision 2 Clip  Firmware version: 02.01.16a

Headphones used:
  Standard Sansa Earphones
  Skull Candy FMJ 9mm in-ear
  Sennheiser HD-595 - Full sized headphones

Music used for test:
  Album used:  Kings of Leon - Only By The Night - Length 00:42:39
  Ripped from CD using dBpoweramp - AccurateRip 1411 Kbps Flac 44.1K/s 16 bit Stereo
  Ripped as a single Flac file, 42 minutes 39 seconds long   00:42:39

Codecs used for encoding:
  MP3 lame 3.98
  Ogg aoTuV b5
  Flac 1.2.1

Test Details:

The album was played endlessly on repeat until the battery ran out of juice and the player died (battery low).  Test Results in Hours Minutes Seconds  HH:MMS. Seconds were ignored, not significant.  In any individual data sampling test there is uncertainty.  Don't be surprised at the variation.  You can't calculate to the minute exactly how long your battery will last.

Observation on battery power percentage measurement:
Power percentages through windows property and through the Clips menu vary.  I've seen the clip at 0% but windows reports it at 11%.  Use the Power% like a gas gauge.   It isn't perfectly linear and sometimes it seem to stick.  Turning the Clip off and on can sometimes display a different Power%. 

The Power% measures in increments.  0,7,14,21,28,35,42,50,57,65,71,78,85,92,100

Volume Control Settings used for this test:
  Clips volume control appears to have approximately 40 clicks from zero volume to Max volume
  0 clicks = zero Vol,  10 clicks = 1/4 Vol,  20 clicks = 1/2 Vol,  30 clicks = 3/4 Vol

==========

I don't experience any issues with battery leakage, other than once in awhile I may leave it playing when I am wearing it, or after I unplug it from the power.   The clips battery lasts an amazing long time.       I stick with higher bit rate VBR MP3's  encoded with Lame's codec.  v0 or v2 settings and get around 15 hours of use ( I have never ran out of juice , as I usually plug it back in after a long day).  

I may repeat a few tests in 6 months to see if the battery degrades over time.    They say at 500 charges you will still get 80% battery capacity,  so with normal use I expect the clip lasts a decent time.    At least long enough for the next cheap mp3 player to be released with more memory.

Niko

[Miikerman]

Wow--great, comprehensive benchmarks!

(And amazing to see the Clips lasting 15-17+ hours for well-encoded MP3 files!)

[Cllipman]

>> Silver wins lasting an hour longer than the Black 8GR2 *
    I don't understand why???  I'm going to retest again<<

I think the problem is that there is a quality control issue in the manufacturing of the batteries. You could compare several Clips of the same capacities and colors, and still get wildly different results between them. i.e. there are some 2GB red Clips that play 11 hours...and some that will play for 15 hours...and some that lose charge when not even playing.

The batteries are the weak links in the Clips. You just happen to be seeing the difference between two Clips of different capacities and different colors...but you'd still likely experience those differences even if you were testing two identical Clips. They all have the same battery...and it's just the luck of the draw as to whether any Clip has a good, mediocre or bad battery.

[niko_sama]

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Cllipman wrote:

>> Silver wins lasting an hour longer than the Black 8GR2 *
    I don't understand why???  I'm going to retest again<<

I think the problem is that there is a quality control issue in the manufacturing of the batteries. You could compare several Clips of the same capacities and colors, and still get wildly different results between them. i.e. there are some 2GB red Clips that play 11 hours...and some that will play for 15 hours...and some that lose charge when not even playing.

The batteries are the weak links in the Clips. You just happen to be seeing the difference between two Clips of different capacities and different colors...but you'd still likely experience those differences even if you were testing two identical Clips. They all have the same battery...and it's just the luck of the draw as to whether any Clip has a good, mediocre or bad battery.

---

Yes,  I agree there is battery capacity variations.    They are  probably all within an acceptable power range.   

What I don't understand about the tests is, the Rev 2 black clip was consistantly averaging  longer play times for both ogg and mp3 formatted files.   I did many and the variance was consistant with these two formats.    But on the Flac encoded files,  it was reversed and an unexpected result.     This makes me suspect that the firmware on the Rev 1 clips are clocked at a slower rate for Flac encoding than the Rev 2 clips.    It's just suspect,  I hope someone at sansa notices this, and checks.  

[coyote400]

This is wonderful.  Thank you very much for all the hard work.  You MUST be an engineer.  Can't wait for the next round of results.  Hope it will include tests at full volume, since that is where I play mine (bad ears).   Ratio of charge time to play time seems impressive.  If only they could get an electric car to run that well.

I am confused about one thing.  I can't find an 8GB clip on the Sansa website.

[Marvin_Martian]

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coyote400 wrote:

This is wonderful.  Thank you very much for all the hard work.  You MUST be an engineer.  Can't wait for the next round of results.  Hope it will include tests at full volume, since that is where I play mine (bad ears).   Ratio of charge time to play time seems impressive.  If only they could get an electric car to run that well.

I am confused about one thing.  I can't find an 8GB clip on the Sansa website.

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http://go.shopsansa.com/content/clip

The 8GB clip exists....but you can find it cheaper than the price you will see there.

[Cllipman]

Coyote, If you are in America, run down to a Wal*Mart- they have the 8GB Clip for $49!!!!!

[Miikerman]

And by America, he means the U.S.A.

[Cllipman]

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Miikerman wrote:

And by America, he means the U.S.A.

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They don't have Wal*Mart in Canada or Mexico? 

[Miikerman]

Apparently, the Canadian Wal-Marts aren't having this sales price--I don't know about Mexico ...