Since I have read a lot of negative views on CODI and its unusability, and since I am considering using Cosmo as my main phone, I decided to measure (unscientifically) the impact of several settings on battery life.
The software is already somewhat customized: the Cosmo is rooted, however I am booting a non-root partition. I installed KISS launcher, Opera, termux, F-Droid, set up airmail (without automatic synchronization), Greenify (in non root mode without ADB permissions). Ledison is disabled (does not seem to be working, anyway).
In Settings→Cosmo Settings I turned on “Switch OFF cover display on power down”, though the description is a bit confusing (does the “Power down” refer to powering off the Cosmo, or just putting it to sleep mode?).
In Setting→System Developer options→Background check I turned off F-Droid.
In Play Store, I turned off Autoupdate and everything begining with auto-*
I also disabled Wifi control for all the applications in Settings→Apps & notifications→Special app access.
Standby Intelligent Power Saving has been on, bluetooth, NFC has been turned off. Greenify was used to kill all the background processes just before closing the lid.
Codi ON means the CODI has been turned on from the notification area; the display has been kept off (probably) all the time, there were no incoming calls nor SMS.
Cosmo has been fully charged and after 12 hours of rest (closed lid), I looked at the remaining battery pecentage.
- airplane mode (i.e. the red LED is on), codi off, everything else off: 95%
- airplane mode (i.e. the red LED is on), codi off, wifi ON, everything else off: 93%
- wifi ON, mobile network 4G ON, codi off: 94%
- airplane mode (i.e. the red LED is on), codi ON, wifi off, everything else off: 78%
When the airplane mode is ON, a red LED on the CODI lights on, and I haven’t found a way to turn it off - I have a bad feeling it drains the battery a bit, though the numbers are close enough to the measuring error to be conclusive (compare 2 & 3 above).
The results when CODI is on frankly suck (I actually repeated it twice, to be sure) - instead of about 5%, it drained 22% of the battery in the same timespan. This suggests either some serious power saving issues, or the CODI CPU&chipset is more power hungry than expected or incapable of deep sleep. At this point, Planet would have done better if they connected the cover display as a secondary screen of the mail CPU, not a separate CPU & OS - but then again, it is probably not possible with the Mediatek (or other common) chipset. Perhaps a (scaled down with some circuitry?) copy of the main screen would have been doable - or perhaps not.
Anyway, this isprobably moot with the Astroslide.