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:MM:SS
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
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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:MM:SS. 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
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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
