Linux

Most of them are just a frontend for upower anyway.

What is your desktop environment?

I mean, you can take x samples in y time and average them, but what else?

About that, maybe script it and then display the data in Verve plugin? I've created one a while back but currently don't use the laptop much, so a bug with calculating the remaining time remains. But it might serve as a start.

#!/bin/sh
#
# pretty-print battery-info and time on shell
# last change: 09.01.2024

battery_path=/sys/class/power_supply/BAT0
timeout1=10
timeout2=5

error() { printf '%s:\t%s\n' "error" "$1" >&2; [ -n "$2" ] && exit "$2"; }   # complain to STDERR and exit if given code

[ -d "$battery_path" ] || error "Device has no battery" 1

# while true; do
# 🔌🔌
# reading uevent line for line, because f** idiots and whitespaces in int of voltage
while read line; do
	IFS='='
	set -- $line
	case "$1" in
		"POWER_SUPPLY_NAME")                bat_name="$2"
	;;	"POWER_SUPPLY_STATUS")              bat_state="$2"
	;;	"POWER_SUPPLY_TYPE")                bat_type="$2" # = Battery
	;;	"POWER_SUPPLY_CAPACITY_LEVEL")      bat_warn="$2"
	;;	"POWER_SUPPLY_CAPACITY")            bat_perc="$2"
	;;	"POWER_SUPPLY_ENERGY_NOW")          bat_chrg=$(($2 / 1000))
	;;	"POWER_SUPPLY_ENERGY_FULL")         bat_full=$(($2 / 1000))
	;;	"POWER_SUPPLY_ENERGY_FULL_DESIGN")  bat_chrg_des=$(($2 / 1000))
	;;	"POWER_SUPPLY_VOLTAGE_NOW")         bat_volt=$(($2 / 1000))
	;; esac
done < "$battery_path"/uevent

tt_empty=$(((bat_full - bat_now) / bat_volt)) # TODO
tt_full=$(((bat_full + bat_now) / bat_volt)) # TODO
bat_ttef="${tt_empty:-"$tt_full"}h"
# printf 'tt_empty: %s\n' "$tt_empty"


fgcol="$(tput setaf 2)" # green
reset="$(tput sgr0)"
symbol="🔋"

# conditionals
if [ "$bat_state" = "Discharging" ]; then
	fgcol="$(tput setaf 1)" # red
	symbol="🪫"
fi
if [ "$bat_warn" != "Normal" ]; then
	fgcol="$(tput setaf 1)" # red
	symbol="⚠"
	envwarn "Battery ${bat_name}: ${bat_warn}"
fi

# override bat_ttef only every 2nd time
# if $flipflop; then
	string="${fgcol}${bat_perc}%${reset}/${bat_ttef}"
# 	sleep $timeout1
# 	flipflop=false
# else
# 	symbol="🕑"
# 	string=" $(date +%R)"
# 	sleep $timeout2
# 	flipflop=true
# fi

_time="$(date +%R)"

tput sc # save cursor position
tput cup 0 $(($(tput cols)-20)) # set cursor position
printf "%s %s / %s 🕑\n" "$string" "$symbol" "$_time"
tput rc # reset cursor position

# done

Edit: ah, envwarn is a little utility of me, that puts errors in a statefile, which gets echoed on every shell load.

I never thought about it much but how hard would it be to add PID to your power info?