diff --git a/plugins/available/battery.plugin.bash b/plugins/available/battery.plugin.bash
index d86a1f08..1f758e0c 100644
--- a/plugins/available/battery.plugin.bash
+++ b/plugins/available/battery.plugin.bash
@@ -2,8 +2,10 @@
 about-plugin 'display info about your battery charge level'
 
 function ac_adapter_connected() {
+	local batteries
 	if _command_exists upower; then
-		upower -i "$(upower -e | grep --max-count=1 -i BAT)" | grep 'state' | grep -q 'charging\|fully-charged'
+		batteries="$(upower -e | grep --max-count=1 -i BAT)"
+		upower -i "${batteries}" | grep 'state' | grep -q 'charging\|fully-charged'
 	elif _command_exists acpi; then
 		acpi -a | grep -q "on-line"
 	elif _command_exists pmset; then
@@ -16,8 +18,10 @@ function ac_adapter_connected() {
 }
 
 function ac_adapter_disconnected() {
+	local batteries
 	if _command_exists upower; then
-		upower -i "$(upower -e | grep --max-count=1 -i BAT)" | grep 'state' | grep -q 'discharging'
+		batteries="$(upower -e | grep --max-count=1 -i BAT)"
+		upower -i "${batteries}" | grep 'state' | grep -q 'discharging'
 	elif _command_exists acpi; then
 		acpi -a | grep -q "off-line"
 	elif _command_exists pmset; then
@@ -33,16 +37,17 @@ function battery_percentage() {
 	about 'displays battery charge as a percentage of full (100%)'
 	group 'battery'
 
-	local command_output="no"
+	local command_output batteries
 
 	if _command_exists upower; then
-		command_output=$(upower --show-info "$(upower --enumerate | grep --max-count=1 -i BAT)" | grep percentage | grep -o "[0-9]\+" | head -1)
+		batteries="$(upower --enumerate | grep --max-count=1 -i BAT)"
+		command_output="$(upower --show-info "${batteries:-}" | grep percentage | grep -o '[0-9]\+' | head -1)"
 	elif _command_exists acpi; then
 		command_output=$(acpi -b | awk -F, '/,/{gsub(/ /, "", $0); gsub(/%/,"", $0); print $2}')
 	elif _command_exists pmset; then
-		command_output=$(pmset -g ps | sed -n 's/.*[[:blank:]]+*\(.*%\).*/\1/p' | grep -o "[0-9]\+" | head -1)
+		command_output=$(pmset -g ps | sed -n 's/.*[[:blank:]]+*\(.*%\).*/\1/p' | grep -o '[0-9]\+' | head -1)
 	elif _command_exists ioreg; then
-		command_output=$(ioreg -n AppleSmartBattery -r | awk '$1~/Capacity/{c[$1]=$3} END{OFMT="%05.2f"; max=c["\"MaxCapacity\""]; print (max>0? 100*c["\"CurrentCapacity\""]/max: "?")}' | grep -o "[0-9]\+" | head -1)
+		command_output=$(ioreg -n AppleSmartBattery -r | awk '$1~/Capacity/{c[$1]=$3} END{OFMT="%05.2f"; max=c["\"MaxCapacity\""]; print (max>0? 100*c["\"CurrentCapacity\""]/max: "?")}' | grep -o '[0-9]\+' | head -1)
 	elif _command_exists WMIC; then
 		command_output=$(WMIC PATH Win32_Battery Get EstimatedChargeRemaining /Format:List | grep -o '[0-9]\+' | head -1)
 	else