Sansa Fuze - Ultra short battery life :/

[redrick]

Hi,

Please excuse my ignorance re batteries- I'm trying to learn.

I note that in Sadzior's bench run it starts with 93% and 4141 mV.  It ends with 0% but still 3298 mV. 

The manual says "Level The percent level of the battery estimated by Rockbox, and not the actual battery level. The actual battery level can be seen from the Voltage column."

Am I reading this wrong, or does the device need at least 3300mV to operate, or could the scales just be wrong?

Also, it did go from 40% to 0 in less than an hour, after taking more than 4 hours to go from 55% to 40%.  Time Left shows similarly.  at 40% it showed over 4 hours left but was going down 6 minutes for each actual minute of running.  By the end it was 12 to 1.

I have a e200.  I think I'll do a battery bench.txt & see if I get similar results, also to keep a small chart to show what the percentages really mean.

[saratoga]

Am I reading this wrong, or does the device need at least 3300mV to operate, or could the scales just be wrong?

3300mV is the lowest voltage the battery can provide.  That means its dead.  See wikipedia for more about lipoly batteries. 

I have a e200.  I think I'll do a battery bench.txt & see if I get similar results, also to keep a small chart to show what the percentages really mean.

The battery bench includes the percentages. 

[redrick]

But not accurate percentages.  For example in Sadzior's case when it showed 40% he really had less than 10% usage left.  (He got more than 10 hours out of a full charge, but from "40%" to 0 went by in just one hour.)

[saratoga]

But not accurate percentages.  For example in Sadzior's case when it showed 40% he really had less than 10% usage left.  (He got more than 10 hours out of a full charge, but from "40%" to 0 went by in just one hour.)

Yes but you don't need to keep a chart.  The log file has the given percentages, and you can compute the actual percentages from the times.

[sadzior]

redrick i am really looking forward to seeing your battery bench and comparing it to mine

[link343]

Has there been a solution to this problem yet? I am also getting a short battery life. I got about 7 hours off of my 10 month old fuze.

[saratoga]

Not yet.

[Dael]

Hello everyone.

Just to report - I'm having the same problem but to a certain extreme. Today my fully charged fuze destroyed the battery in two (and I am in no way kidding) hours. I will try to run the benchmark as soon as I'm able to.

Regards

[funman]

With current builds I play mp3 for ~ 14h30, things have improved a bit since last release but I think it depends on the codec you use

[saratoga]

With current builds I play mp3 for ~ 14h30, things have improved a bit since last release but I think it depends on the codec you use

This is the V1 right?  I think since we don't scale the CPU clock all that low, mp3, aac, vorbis, flac, wma should all be pretty similar. 

[sadzior]

Hello everyone.

Just to report - I'm having the same problem but to a certain extreme. Today my fully charged fuze destroyed the battery in two (and I am in no way kidding) hours. I will try to run the benchmark as soon as I'm able to.

Regards

now that will be interesting to see, do it asap!

[Etoja]

Hm, I have the same problem -  over 2 hours of playing 64-44 mp3 files drains the battery to the end on my freshly charged rockboxed Fuze v.2. Strange...
PS Come to think about it, it might be the incorrect reading of the battery

[Dael]

Code: [Select]

Battery bench run for Sandisk Sansa Fuze version 3.5.1

07:47:47,  28067,     038%,     03:56,         3642,     -,  -,  -
07:48:48,  28128,     037%,     03:50,         3637,     -,  -,  -
07:49:48,  28188,     036%,     03:44,         3631,     -,  -,  -
07:50:48,  28248,     036%,     03:44,         3626,     -,  -,  -
07:51:48,  28308,     035%,     03:37,         3620,     -,  -,  -
07:52:48,  28368,     035%,     03:37,         3616,     -,  -,  -
07:53:48,  28428,     034%,     03:31,         3611,     -,  -,  -
07:54:48,  28488,     033%,     03:25,         3603,     -,  -,  -
07:55:48,  28548,     033%,     03:25,         3597,     -,  -,  -
07:56:48,  28608,     032%,     03:19,         3590,     -,  -,  -
07:57:48,  28668,     031%,     03:13,         3585,     -,  -,  -
07:58:34,  28714,     030%,     03:09,         3578,     -,  -,  -
07:59:34,  28774,     030%,     03:06,         3573,     -,  -,  -
08:00:35,  28835,     029%,     03:00,         3564,     -,  -,  -
08:01:35,  28895,     028%,     02:54,         3555,     -,  -,  -
08:02:35,  28955,     027%,     02:48,         3548,     -,  -,  -
08:03:35,  29015,     026%,     02:41,         3540,     -,  -,  -
08:04:35,  29075,     025%,     02:35,         3533,     -,  -,  -
08:05:35,  29135,     025%,     02:35,         3526,     -,  -,  -
08:06:35,  29195,     024%,     02:29,         3519,     -,  -,  -
08:07:35,  29255,     023%,     02:23,         3510,     -,  -,  -
08:08:35,  29315,     022%,     02:16,         3501,     -,  -,  -
08:09:35,  29375,     021%,     02:10,         3492,     -,  -,  -
08:10:35,  29435,     020%,     02:04,         3483,     -,  -,  -
08:11:35,  29495,     019%,     01:58,         3473,     -,  -,  -
08:12:35,  29555,     018%,     01:52,         3465,     -,  -,  -
08:13:35,  29615,     016%,     01:39,         3452,     -,  -,  -
08:14:26,  29666,     015%,     01:36,         3443,     -,  -,  -
08:15:26,  29726,     014%,     01:27,         3432,     -,  -,  -
08:16:26,  29786,     013%,     01:20,         3418,     -,  -,  -
08:17:26,  29846,     011%,     01:08,         3403,     -,  -,  -
08:18:26,  29906,     009%,     00:56,         3387,     -,  -,  -
08:19:26,  29966,     007%,     00:43,         3371,     -,  -,  -
08:20:26,  30026,     006%,     00:37,         3356,     -,  -,  -
08:20:44,  30044,     005%,     00:34,         3352,     -,  -,  -
08:21:44,  30104,     003%,     00:18,         3334,     -,  -,  -
08:22:44,  30164,     001%,     00:06,         3315,     -,  -,  -
08:23:44,  30224,     000%,     00:00,         3298,     -,  -,  -

Sorry can't fit the whole thing in one post and can't doublepost. If you'd tell me how to post the whole thing I would gladly do that. I don't really understand the chart but if it suggests I had a 8 hour long session it's full of bullcrap because the battery lasted 4 hours at max this time.

[mc2739]

Code: [Select]

Battery bench run for Sandisk Sansa Fuze version 3.5.1

If you use a current build instead of the release build, you will see better battery run times.  There have been several recent commits that have increased run time.

Sorry can't fit the whole thing in one post and can't doublepost. If you'd tell me how to post the whole thing I would gladly do that. I don't really understand the chart but if it suggests I had a 8 hour long session it's full of bullcrap because the battery lasted 4 hours at max this time.

You should be able to upload your battery_bench.txt file with your post.  Alternatively, you could use a pastebin site, such as pastebin.com, and then paste the link.

I don't really understand the chart

The first and second columns show the time as reported by the device's real time clock.

The third and fourth columns show the estimated remaining runtime (percentage and hh:mm).  These are only accurate if the software has been calibrated to the battery discharge curve.

The fifth column is the battery voltage  in millivolts.

[Dael]

Of course. Sorry, it's just me being silly. Here is the full report. I will now update the software on my fuze, run another test and literally sit near the player the whole time just to make sure I am not missing anything.

The benchmark starts from 77% which would be the maximum charge I could get.