Conversation started Aug 14, 2016 at 16:48.
bwDraco
bwDraco
Aug 14, 2016 16:48
Actually the battery on the Nexus 9 is not fully charged. The full charge capacity seems to be closer to 6380 mAh, more than 95% of original charge capacity. This is excellent given the age of the device.
Also:
1 hour ago, by bwDraco
I am able to get detailed battery status through /sys/class/power_supply_bms. Current full charge capacity is 2538 of 2704 mAh (93.9%), computed using charge_full and charge_full_design.
It should be /sys/class/power_supply/bms.
As for my Nexus 5X, when charging is disabled, it seems that the battery still discharges when plugged in, albeit very slowly (according to Ampere). Regardless, being able to keep tabs on the battery and even programmatically disable charging lets me maximize battery service life.
This is because I can tell the phone to stop charging at a certain charge level since full charges are stressful on the battery. While it's not as good as automatically stopping charging at a certain charge level (e.g. 80%), software charging control means I can keep the phone plugged in and manage charging without having to disconnect the charger repeatedly or repeatedly charge and discharge the battery near the target battery level.
Yet another park of root: being able to extend battery service life.
Your thoughts on charge control? I wish more devices exposed these sorts of charge controls so that I can extend battery service life...
!!/wiki Battery management system
ChatBot John Cavil
ChatBot John Cavil
Battery management system
A battery management system (BMS) is any electronic system that manages a rechargeable battery (cell or battery pack), such as by protecting the battery from operating outside its Safe Operating Area, monitoring its state, calculating secondary data, reporting that data, controlling its environment, authenticating it and / or balancing it. A battery pack built together with a battery management system with an external communication data bus is a smart battery pack. A smart battery pack must be charged by a smart battery charger. == Functions == === Monitor === A BMS may monitor the stat...
bwDraco
bwDraco
Aug 14, 2016 17:06
In Kernel Adiutor, I added a switch custom control to manage this.
djsmiley2k
djsmiley2k
Hmmm
but what if it ALREADY stops at 80%?
bwDraco
bwDraco
No it doesn't. Charging normally stops at 4.35V, which is a true full charge.
djsmiley2k
djsmiley2k
you've removed the battery from the device and tested it yourself manually?
what if teh battery is actually 4.5V ?
:)
bwDraco
bwDraco
That's what the system is reporting. No, I don't expect the BMS to be lying about voltage.
pastebin.com/7tKTCDHP 
{"version":1,"control":{"apply":"#!\/system\/bin\/sh\n\nstatus=$1\n\n#$status is either 1 or 0\necho $status > \/sys\/class\/power_supply\/battery\/battery_charging_enabled","enable":"#!\/system\/bin\/sh\n\n#Returns 1 if enabled and 0 if disabled\ncat \/sys\/class\/power_supply\/battery\/battery_charging_enabled","title":"Battery Charging","description":"Disable to stop charging while plugged in (useful for limiting maximum charge level)","id":"switch"}}
Only tested on Nexus 5X with franco.Kernel. May not work on your device.
 
Conversation ended Aug 14, 2016 at 17:22.