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pm3840

Member

Registered: 2013-12-16

Posts: 61

XFCE4: Battery drop to 95% when plugged in

I notice that battery is allowed to drop to 95% occasionally when plugged in at all times. Is this normal?
Is this an xfce thing or kernel thing? Is the purpose to prolong battery life of some sort by not constantly staying 100% charged?

seth

Member

Registered: 2012-09-03

Posts: 52,218

Re: XFCE4: Battery drop to 95% when plugged in

The battery/firmware will have/expose some threshold for this and it is not advisable at all to keep the battery at 100% because the limits are the most damage causing areas.
Eg. lenovo allows you to cap the load at 60% for that exact scenario and reason, https://wiki.archlinux.org/title/Laptop … ation_mode

Keeping your battery on external power and 100% is pretty much the fastest way to kill it.

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mpan

Member

Registered: 2012-08-01

Posts: 1,220

Website

Re: XFCE4: Battery drop to 95% when plugged in

Yes, it’s normal to keep battery below 100% charge. This increases its life.

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pm3840

Member

Registered: 2013-12-16

Posts: 61

Re: XFCE4: Battery drop to 95% when plugged in

Just to share a DP then: my HP laptop has been running for 3 years on external power and at least on paper kernel reports 100% capacity. It's basically my replacement for a tower and daily driver.

Any idea where this 95% is controlled? I don't have any extra HP driver installed. Is it hardcoded in kernel?

pm3840

Member

Registered: 2013-12-16

Posts: 61

Re: XFCE4: Battery drop to 95% when plugged in

cycle count is actually higher than i expect:

/sys/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0A:00/power_supply/BAT0] cat uevent 
POWER_SUPPLY_NAME=BAT0
POWER_SUPPLY_TYPE=Battery
POWER_SUPPLY_STATUS=Full
POWER_SUPPLY_PRESENT=1
POWER_SUPPLY_TECHNOLOGY=Li-ion
POWER_SUPPLY_CYCLE_COUNT=329
POWER_SUPPLY_VOLTAGE_MIN_DESIGN=11340000
POWER_SUPPLY_VOLTAGE_NOW=12609000
POWER_SUPPLY_ENERGY_FULL_DESIGN=36650000
POWER_SUPPLY_ENERGY_FULL=36650000
POWER_SUPPLY_ENERGY_NOW=36650000
POWER_SUPPLY_CAPACITY=100
POWER_SUPPLY_CAPACITY_LEVEL=Full
POWER_SUPPLY_MODEL_NAME=Primary
POWER_SUPPLY_MANUFACTURER=Hewlett-Packard
POWER_SUPPLY_SERIAL_NUMBER= 

seth

Member

Registered: 2012-09-03

Posts: 52,218

Re: XFCE4: Battery drop to 95% when plugged in

Most likey the UEFI - there's a hp_wmi module but it doesn't seem to have any parameters.
You could pay attention whether the charge is always at 99-100% when you're booting - if not it drops w/o any OS possibly having an impact on it.

Careful about the battery stats, those are guesstimates.
Though oc, if you're using the battery more or less like an UPS, you're probably not /that/ concerned anyway.

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pm3840

Member

Registered: 2013-12-16

Posts: 61

Re: XFCE4: Battery drop to 95% when plugged in

We have very reliable power here so no concern there.

I don't even turn if off it's either running or in suspend state.

The 95% event happens perhaps once a week I don't have enough data with 18 days uptime.