diff --git a/chip-battery.sh b/chip-battery.sh
index 4c9beb1..7c31d58 100644
--- a/chip-battery.sh
+++ b/chip-battery.sh
@@ -61,7 +61,7 @@ function getChargeCurrent() {
 # shuts the system down if too less voltage
 function verifyBatteryVoltage() {
   echo "$(isBatteryAvailable)"
-  if [ "$(isBatteryAvailable)" -eq "1" ] ; then
+  if [ "$?" -eq "1" ] ; then
       local voltage=$(getBatteryVoltage)
       local chargeCurrent=$(getChargeCurrent)
       echo "Voltage: $voltage"