al-skel/home/.config/awesome/vicious/widgets/bat.lua

---------------------------------------------------
-- Licensed under the GNU General Public License v2
--  * (c) 2010, Adrian C. <anrxc@sysphere.org>
--  * (c) 2013, NormalRa  <normalrawr@gmail.com>
---------------------------------------------------

-- {{{ Grab environment
local tonumber = tonumber
local setmetatable = setmetatable
local string = { format = string.format }
local helpers = require("vicious.helpers")
local math = {
  min = math.min,
  floor = math.floor
}
-- }}}


-- Bat: provides state, charge, remaining time, and wear for a requested battery
-- vicious.widgets.bat
local bat = {}


-- {{{ Battery widget type
local function worker(format, warg)
  if not warg then return end

  local battery = helpers.pathtotable("/sys/class/power_supply/"..warg)
  local battery_state = {
    ["Full\n"]        = "↯",
    ["Unknown\n"]     = "⌁",
    ["Charged\n"]     = "↯",
    ["Charging\n"]    = "+",
    ["Discharging\n"] = "−"
  }

  -- Check if the battery is present
  if battery.present ~= "1\n" then
    return {battery_state["Unknown\n"], 0, "N/A", 0}
  end


  -- Get state information
  local state = battery_state[battery.status] or battery_state["Unknown\n"]

  -- Get capacity information
  if battery.charge_now then
    remaining, capacity = battery.charge_now, battery.charge_full
    capacity_design = battery.charge_full_design or capacity
  elseif battery.energy_now then
    remaining, capacity = battery.energy_now, battery.energy_full
    capacity_design = battery.energy_full_design or capacity
  else
    return {battery_state["Unknown\n"], 0, "N/A", 0}
  end

  -- Calculate capacity and wear percentage (but work around broken BAT/ACPI implementations)
  local percent = math.min(math.floor(remaining / capacity * 100), 100)
  local wear = math.floor(100 - capacity / capacity_design * 100)


  -- Get charge information
  if battery.current_now then
    rate = tonumber(battery.current_now)
  elseif battery.power_now then
    rate = tonumber(battery.power_now)
  else
    return {state, percent, "N/A", wear}
  end

  -- Calculate remaining (charging or discharging) time
  local time = "N/A"

  if rate ~= nil and rate ~= 0 then
    if state == "+" then
      timeleft = (tonumber(capacity) - tonumber(remaining)) / tonumber(rate)
    elseif state == "−" then
      timeleft = tonumber(remaining) / tonumber(rate)
    else
      return {state, percent, time, wear}
    end

    -- Calculate time
    local hoursleft   = math.floor(timeleft)
    local minutesleft = math.floor((timeleft - hoursleft) * 60 )

    time = string.format("%02d:%02d", hoursleft, minutesleft)
  end

  return {state, percent, time, wear}
end
-- }}}

return setmetatable(bat, { __call = function(_, ...) return worker(...) end })