diff --git a/plugins/battery/battery.plugin.zsh b/plugins/battery/battery.plugin.zsh
index 6b6684716..6fe801c9f 100644
--- a/plugins/battery/battery.plugin.zsh
+++ b/plugins/battery/battery.plugin.zsh
@@ -11,22 +11,21 @@
 # Modified to add support for FreeBSD     #
 ###########################################
 
-if [[ "$OSTYPE" = darwin* ]] ; then
+if [[ "$OSTYPE" = darwin* ]]; then
 
-  function battery_pct() {
-    local smart_battery_status="$(ioreg -rc "AppleSmartBattery")"
-    typeset -F maxcapacity=$(echo $smart_battery_status | grep '^.*"MaxCapacity"\ =\ ' | sed -e 's/^.*"MaxCapacity"\ =\ //')
-    typeset -F currentcapacity=$(echo $smart_battery_status | grep '^.*"CurrentCapacity"\ =\ ' | sed -e 's/^.*CurrentCapacity"\ =\ //')
-    integer i=$(((currentcapacity/maxcapacity) * 100))
-    echo $i
+  function battery_is_charging() {
+    ioreg -rc AppleSmartBattery | command grep -q '^.*"ExternalConnected"\ =\ Yes'
   }
 
-  function plugged_in() {
-    [ $(ioreg -rc AppleSmartBattery | grep -c '^.*"ExternalConnected"\ =\ Yes') -eq 1 ]
+  function battery_pct() {
+    local smart_battery_status="$(ioreg -rc AppleSmartBattery)"
+    local -F maxcapacity=$(command grep '^.*"MaxCapacity"\ =\ ' <<< $smart_battery_status | sed -e 's/^.*"MaxCapacity"\ =\ //')
+    local -F currentcapacity=$(command grep '^.*"CurrentCapacity"\ =\ ' <<< $smart_battery_status | sed -e 's/^.*CurrentCapacity"\ =\ //')
+    echo $(( (currentcapacity/maxcapacity) * 100 ))
   }
 
   function battery_pct_remaining() {
-    if plugged_in ; then
+    if battery_is_charging; then
       echo "External Power"
     else
       battery_pct
@@ -35,9 +34,9 @@ if [[ "$OSTYPE" = darwin* ]] ; then
 
   function battery_time_remaining() {
     local smart_battery_status="$(ioreg -rc "AppleSmartBattery")"
-    if [[ $(echo $smart_battery_status | grep -c '^.*"ExternalConnected"\ =\ No') -eq 1 ]] ; then
-      timeremaining=$(echo $smart_battery_status | grep '^.*"AvgTimeToEmpty"\ =\ ' | sed -e 's/^.*"AvgTimeToEmpty"\ =\ //')
-      if [ $timeremaining -gt 720 ] ; then
+    if [[ $(echo $smart_battery_status | command grep -c '^.*"ExternalConnected"\ =\ No') -eq 1 ]]; then
+      timeremaining=$(echo $smart_battery_status | command grep '^.*"AvgTimeToEmpty"\ =\ ' | sed -e 's/^.*"AvgTimeToEmpty"\ =\ //')
+      if [ $timeremaining -gt 720 ]; then
         echo "::"
       else
         echo "~$((timeremaining / 60)):$((timeremaining % 60))"
@@ -48,11 +47,11 @@ if [[ "$OSTYPE" = darwin* ]] ; then
   }
 
   function battery_pct_prompt () {
-    if [[ $(ioreg -rc AppleSmartBattery | grep -c '^.*"ExternalConnected"\ =\ No') -eq 1 ]] ; then
+    if ioreg -rc AppleSmartBattery | command grep -q '^.*"ExternalConnected"\ =\ No'; then
       b=$(battery_pct_remaining)
-      if [ $b -gt 50 ] ; then
+      if [[ $b -gt 50 ]]; then
         color='green'
-      elif [ $b -gt 20 ] ; then
+      elif [[ $b -gt 20 ]]; then
         color='yellow'
       else
         color='red'
@@ -63,24 +62,20 @@ if [[ "$OSTYPE" = darwin* ]] ; then
     fi
   }
 
-  function battery_is_charging() {
-    [[ $(ioreg -rc "AppleSmartBattery"| grep '^.*"IsCharging"\ =\ ' | sed -e 's/^.*"IsCharging"\ =\ //') == "Yes" ]]
-  }
-
-elif [[ "$OSTYPE" = freebsd*  ]] ; then
+elif [[ "$OSTYPE" = freebsd* ]]; then
 
   function battery_is_charging() {
     [[ $(sysctl -n hw.acpi.battery.state) -eq 2 ]]
   }
 
   function battery_pct() {
-    if (( $+commands[sysctl] )) ; then
-      echo "$(sysctl -n hw.acpi.battery.life)"
+    if (( $+commands[sysctl] )); then
+      sysctl -n hw.acpi.battery.life
     fi
   }
 
   function battery_pct_remaining() {
-    if [ ! $(battery_is_charging) ] ; then
+    if ! battery_is_charging; then
       battery_pct
     else
       echo "External Power"
@@ -88,45 +83,46 @@ elif [[ "$OSTYPE" = freebsd*  ]] ; then
   }
 
   function battery_time_remaining() {
+    local remaining_time
     remaining_time=$(sysctl -n hw.acpi.battery.time)
-    if [[ $remaining_time -ge 0 ]] ; then
-      # calculation from https://www.unix.com/shell-programming-and-scripting/23695-convert-minutes-hours-minutes-seconds.html
-      ((hour=$remaining_time/60))
-      ((minute=$remaining_time-$hour*60))
-      echo $hour:$minute
+    if [[ $remaining_time -ge 0 ]]; then
+      ((hour = $remaining_time / 60 ))
+      ((minute = $remaining_time % 60 ))
+      printf %02d:%02d $hour $minute
     fi
   }
 
   function battery_pct_prompt() {
+    local b color
     b=$(battery_pct_remaining)
-    if [ ! $(battery_is_charging) ] ; then
-      if [ $b -gt 50 ] ; then
+    if battery_is_charging; then
+      echo "∞"
+    else
+      if [[ $b -gt 50 ]]; then
         color='green'
-      elif [ $b -gt 20 ] ; then
+      elif [[ $b -gt 20 ]]; then
         color='yellow'
       else
         color='red'
       fi
       echo "%{$fg[$color]%}$(battery_pct_remaining)%%%{$reset_color%}"
-    else
-      echo "∞"
     fi
   }
 
-elif [[ "$OSTYPE" = linux*  ]] ; then
+elif [[ "$OSTYPE" = linux*  ]]; then
 
   function battery_is_charging() {
-    ! [[ $(acpi 2>/dev/null | grep -c '^Battery.*Discharging') -gt 0 ]]
+    ! acpi 2>/dev/null | command grep -v "rate information unavailable" | command grep -q '^Battery.*Discharging'
   }
 
   function battery_pct() {
-    if (( $+commands[acpi] )) ; then
-      echo "$(acpi 2>/dev/null | cut -f2 -d ',' | tr -cd '[:digit:]')"
+    if (( $+commands[acpi] )); then
+      acpi 2>/dev/null | command grep -v "rate information unavailable" | command grep -E '^Battery.*(Disc|C)harging' | cut -f2 -d ',' | tr -cd '[:digit:]'
     fi
   }
 
   function battery_pct_remaining() {
-    if [ ! $(battery_is_charging) ] ; then
+    if ! battery_is_charging; then
       battery_pct
     else
       echo "External Power"
@@ -134,76 +130,81 @@ elif [[ "$OSTYPE" = linux*  ]] ; then
   }
 
   function battery_time_remaining() {
-    if [[ $(acpi 2>/dev/null | grep -c '^Battery.*Discharging') -gt 0 ]] ; then
-      echo $(acpi 2>/dev/null | cut -f3 -d ',')
+    if ! battery_is_charging; then
+      acpi 2>/dev/null | command grep -v "rate information unavailable" | cut -f3 -d ','
     fi
   }
 
   function battery_pct_prompt() {
-    b=$(battery_pct_remaining) 
-    if [[ $(acpi 2>/dev/null | grep -c '^Battery.*Discharging') -gt 0 ]] ; then
-      if [ $b -gt 50 ] ; then
+    local b color
+    b=$(battery_pct_remaining)
+    if battery_is_charging; then
+      echo "∞"
+    else
+      if [[ $b -gt 50 ]]; then
         color='green'
-      elif [ $b -gt 20 ] ; then
+      elif [[ $b -gt 20 ]]; then
         color='yellow'
       else
         color='red'
       fi
       echo "%{$fg[$color]%}$(battery_pct_remaining)%%%{$reset_color%}"
-    else
-      echo "∞"
     fi
   }
 
 else
   # Empty functions so we don't cause errors in prompts
-  function battery_pct_remaining() {
-  }
-
-  function battery_time_remaining() {
-  }
-
-  function battery_pct_prompt() {
-  }
+  function battery_is_charging { false }
+  function battery_pct \
+    battery_pct_remaining \
+    battery_time_remaining \
+    battery_pct_prompt { }
 fi
 
 function battery_level_gauge() {
-  local gauge_slots=${BATTERY_GAUGE_SLOTS:-10};
-  local green_threshold=${BATTERY_GREEN_THRESHOLD:-6};
-  local yellow_threshold=${BATTERY_YELLOW_THRESHOLD:-4};
-  local color_green=${BATTERY_COLOR_GREEN:-%F{green}};
-  local color_yellow=${BATTERY_COLOR_YELLOW:-%F{yellow}};
-  local color_red=${BATTERY_COLOR_RED:-%F{red}};
-  local color_reset=${BATTERY_COLOR_RESET:-%{%f%k%b%}};
-  local battery_prefix=${BATTERY_GAUGE_PREFIX:-'['};
-  local battery_suffix=${BATTERY_GAUGE_SUFFIX:-']'};
-  local filled_symbol=${BATTERY_GAUGE_FILLED_SYMBOL:-'▶'};
-  local empty_symbol=${BATTERY_GAUGE_EMPTY_SYMBOL:-'▷'};
-  local charging_color=${BATTERY_CHARGING_COLOR:-$color_yellow};
-  local charging_symbol=${BATTERY_CHARGING_SYMBOL:-'⚡'};
+  local gauge_slots=${BATTERY_GAUGE_SLOTS:-10}
+  local green_threshold=${BATTERY_GREEN_THRESHOLD:-$(( gauge_slots * 0.6 ))}
+  local yellow_threshold=${BATTERY_YELLOW_THRESHOLD:-$(( gauge_slots * 0.4 ))}
+  local color_green=${BATTERY_COLOR_GREEN:-%F{green}}
+  local color_yellow=${BATTERY_COLOR_YELLOW:-%F{yellow}}
+  local color_red=${BATTERY_COLOR_RED:-%F{red}}
+  local color_reset=${BATTERY_COLOR_RESET:-%{%f%k%b%}}
+  local battery_prefix=${BATTERY_GAUGE_PREFIX:-'['}
+  local battery_suffix=${BATTERY_GAUGE_SUFFIX:-']'}
+  local filled_symbol=${BATTERY_GAUGE_FILLED_SYMBOL:-'▶'}
+  local empty_symbol=${BATTERY_GAUGE_EMPTY_SYMBOL:-'▷'}
+  local charging_color=${BATTERY_CHARGING_COLOR:-$color_yellow}
+  local charging_symbol=${BATTERY_CHARGING_SYMBOL:-'⚡'}
 
-  local battery_remaining_percentage=$(battery_pct);
+  local battery_remaining_percentage=$(battery_pct)
+  local filled empty gauge_color
 
   if [[ $battery_remaining_percentage =~ [0-9]+ ]]; then
-    local filled=$(((( $battery_remaining_percentage + $gauge_slots - 1) / $gauge_slots)));
-    local empty=$(($gauge_slots - $filled));
+    filled=$(( ($battery_remaining_percentage * $gauge_slots) / 100 ))
+    empty=$(( $gauge_slots - $filled ))
 
-    if [[ $filled -gt $green_threshold ]]; then local gauge_color=$color_green;
-    elif [[ $filled -gt $yellow_threshold ]]; then local gauge_color=$color_yellow;
-    else local gauge_color=$color_red;
+    if [[ $filled -gt $green_threshold ]]; then
+      gauge_color=$color_green
+    elif [[ $filled -gt $yellow_threshold ]]; then
+      gauge_color=$color_yellow
+    else
+      gauge_color=$color_red
     fi
   else
-    local filled=$gauge_slots;
-    local empty=0;
-    filled_symbol=${BATTERY_UNKNOWN_SYMBOL:-'.'};
+    filled=$gauge_slots
+    empty=0
+    filled_symbol=${BATTERY_UNKNOWN_SYMBOL:-'.'}
   fi
 
-  local charging=' ' && battery_is_charging && charging=$charging_symbol;
+  local charging=' '
+  battery_is_charging && charging=$charging_symbol
 
+  # Charging status and prefix
   printf ${charging_color//\%/\%\%}$charging${color_reset//\%/\%\%}${battery_prefix//\%/\%\%}${gauge_color//\%/\%\%}
-  printf ${filled_symbol//\%/\%\%}'%.0s' {1..$filled}
+  # Filled slots
+  [[ $filled -gt 0 ]] && printf ${filled_symbol//\%/\%\%}'%.0s' {1..$filled}
+  # Empty slots
   [[ $filled -lt $gauge_slots ]] && printf ${empty_symbol//\%/\%\%}'%.0s' {1..$empty}
+  # Suffix
   printf ${color_reset//\%/\%\%}${battery_suffix//\%/\%\%}${color_reset//\%/\%\%}
 }
-
-