battery charge indication

[khumarahn]

I can't make the battery indication work with lxde or lxqt. It seems that it is because some standard files like charge_now and charge_full or energy_now and energy_full are missing in the device folder:

# ls -al /sys/class/power_supply/battery
total 0
drwxr-xr-x 3 root root    0 Nov  5 14:37 .
drwxr-xr-x 5 root root    0 Nov  5 14:37 ..
-r--r--r-- 1 root root 4096 Nov  5 14:38 capacity
-r--r--r-- 1 root root 4096 Nov  5 14:48 current_now
lrwxrwxrwx 1 root root    0 Nov  5 14:48 device -> ../../../axp81x-supplyer.47
-r--r--r-- 1 root root 4096 Nov  5 14:48 energy_full_design
-r--r--r-- 1 root root 4096 Nov  5 14:48 health
-r--r--r-- 1 root root 4096 Nov  5 14:38 model_name
-r--r--r-- 1 root root 4096 Nov  5 14:48 online
drwxr-xr-x 2 root root    0 Nov  5 14:48 power
-r--r--r-- 1 root root 4096 Nov  5 14:48 present
-r--r--r-- 1 root root 4096 Nov  5 14:38 status
lrwxrwxrwx 1 root root    0 Nov  5 14:38 subsystem -> ../../../../../../class/power_supply
-r--r--r-- 1 root root 4096 Nov  5 14:48 technology
-r--r--r-- 1 root root 4096 Nov  5 14:48 temp
-r--r--r-- 1 root root 4096 Nov  5 14:38 type
-rw-r--r-- 1 root root 4096 Nov  5 14:37 uevent
-r--r--r-- 1 root root 4096 Nov  5 14:48 voltage_max_design
-r--r--r-- 1 root root 4096 Nov  5 14:48 voltage_min_design
-r--r--r-- 1 root root 4096 Nov  5 14:48 voltage_now

There is instead voltage_now, voltage_min_design and voltage_max_design, and probably the battery indication can be patched to use them. Or maybe one can make the energy or charge files appear?

P.S.: The same applies to the popular cbatticon, this is how it determines remaining capacity:

    if (use_charge == FALSE) {
        return get_sysattr_double (battery_path, "energy_now", capacity);
    } else {
        return get_sysattr_double (battery_path, "charge_now", capacity);
    }

https://github.com/valr/cbatticon/blob/46bdd031c28d8d41807e4803880874cff2fa9cd5/cbatticon.c#L582

[khumarahn]

One of the values is like 1000 times less than it should be:

$ cat /sys/class/power_supply/battery/voltage_min_design 
3300
$ cat /sys/class/power_supply/battery/voltage_max_design 
4200000
$ cat /sys/class/power_supply/battery/voltage_now
3973000

[khumarahn]

a dirty patch for lxpanel-0.9.3: https://pastebin.com/YniYSytz. It shows the battery percentage, but does not estimate the remaining time. Partly because the battery capacity is reported as 7mWh, while I'd expect it to be 30Wh:

$ cat /sys/class/power_supply/battery/energy_full_design
7000

I see that the reported voltage changes a lot suddenly on adapter plug in/out, by like 0.2V, this is strange.

[binutzu]

Just flashed image version 1.2 and while setting/tidying up the desktop again i noticed that the Mate battery charge monitoring plugin also does not recognize the battery - says running on AC. At the same time the "default" power manager (icon) seems to work ok: on battery + percentage.

On a different matter, there should be another way to update the system with the officially supported distro beside wiping the content of emmc...

[DanKoloff]

@binutzu We are working on a better way of update. It is possible that certain plugins would experience difficulties, that is why we provide a custom charge indicator, that is tested to work.

[macandchief]

May I ask: How many hours do you get approximately with the battery e.g. on 1/3 surfing, 1/3 video and 1/3 text editing?

[khumarahn]

I'd say around 9 hours. Maybe shorter or longer.

[binutzu]

@DanKoloff I updated my system to Ubuntu Bionic as described in posts of Olimex Forum for Teres-Laptop. It worked fine but the only thing remaining is the battery level display. You mentioned that Olimex provides a custom charge indicator - is that a Mate Desktop specific one and is the source code available? I did not find it in this repo.

[jcstaudt]

These are the only battery charge indicators I see, and believe them to be irrelevant. I have only ever seen battery_charge.bmp when the laptop is plugged in while powered down. I am using Olimex's OEM image v1.4:

The tooltip states System is running on AC power. No battery present when plugged in and when not plugged in. (This statement has often confused me on many laptops as the power input is post-DC-conversion, but that's quite out-of-scope of this issue :smiley:)