iAudio X5: battery life fix (at least partial)

[bk]

http://www.rockbox.org/tracker/task/5639 (Ulrich Pegelow)

Patch puts the USBOTG chip to sleep similar to the H3xx situation. Author claims 24+ hours of battery life on an X5L with this patch. I installed and will test over the next few days.

Testers and battery benchmarks needed!

[Bagder]

Patch puts the USBOTG chip to sleep similar to the H3xx situation. Author claims 24+ hours of battery life on an X5L with this patch. I installed and will test over the next few days.

Really cool! How does the 24+ hours compare with the original firmware's runtime?

[nicolinux]

Thank you very much for this !

The official runtime is 35 hours so we get closer here !

[RaeNye]

I got 5%/hour battery drop (192vbr mp3, vol ~ -25), so 25 hours is prolly a good estimate.

[infamis]

I got 5%/hour battery drop (192vbr mp3, vol ~ -25), so 25 hours is prolly a good estimate.

-25 volume, damn you must have good hearing!

Currently trying this patch out also, definitely feels like an improvement; we'll see when the day is over. I usually get about 6-7 hours (w/non-patched RB) though most my files are about q5/q6 ogg, and hardly ever use the headphone-out (always the line out with my headphone-amp or if I got it plugged into the aux-port of my car radio).

[upegelow]

Currently trying this patch out also, definitely feels like an improvement; we'll see when the day is over. I usually get about 6-7 hours (w/non-patched RB) though most my files are about q5/q6 ogg, and hardly ever use the headphone-out (always the line out with my headphone-amp or if I got it plugged into the aux-port of my car radio).
[/quote]

One thing worth to mention if we compare different file types:
On a x5l with vanilla rockbox I get 15.5 hours playtime for MP3@128k and 14.5 hours for OGG@Q6. A difference of 1 hour.

Now calculating the current draw:

current draw = capacity / play time
capacity = 2160 (96% of nominal capacity)

This makes

140mA for MP3@128k
150mA for OGG@Q6

My patch will reduce current draw by about 50mA in both cases. In terms of play time this makes

24 hours for MP3@128k, but only
21.6 hours for OGG@Q6.

So the difference is now 2.4 hours. In other words: the lower the overall power consumption, the higher the difference in play time between different codecs!
Your 6 hours with OGG@Q6 will probably turn out to be 9 hours with the patch applied.