4G iPod 1100mAh Battery Estimate

[imaginal]

Hi there. I recently bought a 1100mAh battery replacement from kokopelli music for my 4G ipod. After fully charging it and setting the battery capacity option to 1100mAh, the estimated time left was 7h35min. I told them about this, and they said that the battery sounded defective, and sent me a new one.

I installed the new one, but it too only shows 7h35min of playback. Did I really get 2 defective batteries? Or is this something weird with rockbox? Thank you for all of your help!

[soap]

That estimate is calculated based on your input of the battery capacity, and Rockbox's assumed power draw.  It has nothing to do with the condition of the battery - your first one was not defective, and neither is your replacement.
The battery estimates are known to be off on the iPods, didn't know it was that far off on the 4G, though.

[imaginal]

Strange. I ran 2 different rundown album/repeat tests. Both of them actually gave me 10 hours 20 minutes of real drain time. (battery_bench plugin) It still seems a little weak for the battery, but much better than 7.5 hours. Any way I can tweak the estimates?

[soap]

Easiest way is to lie to Rockbox about your battery capacity.  (1516 mah should be about right) IF Rockbox lets you set a value that high.
Harder way is to post your battery benchmarks to the wiki and ask a developer to modify the discharge curve.
Harder way still is to do said work yourself.

[imaginal]

Lying only lets me go up to 1200mAh, so that really doesn't help. Where is the correct place to post the benchfile in the wiki?

Moreover, tweaking this myself sounds like a dangerous road, but where would I start to look?

[saratoga]

The "percent_to_volt_discharge" table in \firmware\target\arm\ipod\powermgmt-ipod-pcf.c contains the battery discharge curve (used for the battery meter itself), and the current use is in /firmware/export/powermgmt.h, although looking at that file there is no entry at all for the 4G which is probably why the estimate is nonsense.  I don't remember where the battery sizes are kept.

I'll commit a reasonable number for the 4G now, but it won't account for your larger battery.

[soap]

Where is the correct place to post the benchfile in the wiki?

http://www.rockbox.org/twiki/bin/view/Main/IpodRuntime

Please note the (improved) battery benchmark file naming conventions people have been using.  I think the last few 5th gen benchmark file names will point you in the right direction.

There are currently no attached battery bench files for the 4G - will be nice to see yours - and all the runtimes claimed are old enough (before some massive power-saving changes) to be worthless except as historical documentation.

[dannyboi]

I'm wondering what I should set the battery draw value in RockBox to, for my 5.5G 80GB iPod?

It goes from 500mah up to 1000mah.

[soap]

I'm wondering what I should set the battery draw value in RockBox to, for my 5.5G 80GB iPod?

It goes from 500mah up to 1000mah.

That's not a "draw" value, that is the capacity value of your battery used when estimating runtime.
Your player came stock with a 600mAh battery.