TLP 1.4 Test: Battery Care for Samsung laptops
Read the overview document first.
Samsung laptops using the
samsung_laptop driver have a feature called
'battery life extender', basically a fixed stop charge threshold at 80%.
The hardware behaviour is:
Connected to the charger, charging stops when the charge level reaches the stop threshold
If the charge level is higher than the stop threshold, the battery will not discharge automatically; it will only be discharged when the charger is removed i.e. the laptop runs on battery
When suitable hardware has been detected,
tlp-stat -b shows:
+++ Battery Care Plugin: samsung Supported features: charge threshold Driver usage: * vendor (samsung_laptop) = active (charge threshold) Parameter value range: * STOP_CHARGE_THRESH_BAT0: 0(off)..1(on) -- battery life extender /sys/devices/platform/samsung/battery_life_extender = 1
How it works
Battery charging is a process not controlled by TLP itself, but by the laptop's embedded controller (EC). This makes the process work even when switched off or no operating system is running. You cannot change the basic behavior, it is hard-coded into the EC firmware by the vendor. TLP just writes the charge threshold into the EC with the help of the kernel driver, the EC takes care of the rest.
Packages are provided at the download page.
Important: please provide all terminal input and output from the test cases via an individual Gist and link it in your post below.
1. Configure and enable battery life extender
Edit /etc/tlp.conf (or a config file of your choice under /etc/tlp.d/):
Note: 0=life extender off/1=life extender on
Connect the charger.
Enter the following commands in a terminal (as root or with
tlp start tlp-stat -s -c -b
battery_life_extender = 1.
2. Verify the charging process
- Let the laptop run on battery power until the charge level falls below at least 70%
- Connect the charger and see if charging starts
- Verify that charging stops at 80%
Enter the command (as root or with
3. Disable battery life extender and return to full charge
Edit the config file used above:
Enter the commands (as root or with
tlp fullcharge tlp-stat -b
battery_life_extender = 0 and the battery gets fully charged.
What else should I check?
- Please report if the battery life extender takes effect at a value other than 80%
- Are there Samsung laptops with more than one battery (
tlp-stat -bshould show)?
TLP 1.4 is released. Have fun and test please!