diff --git a/system-info/system-info-WSL.sh b/system-info/system-info-WSL.sh
index 8274d83..d42f3aa 100755
--- a/system-info/system-info-WSL.sh
+++ b/system-info/system-info-WSL.sh
@@ -31,7 +31,9 @@ while true; do
   raw_battery=$(powershell.exe -NoProfile \
     "(Get-WmiObject win32_battery).EstimatedChargeRemaining" \
     | sed 's/\r//')
-  battery=$(printf "%3d%%" "$raw_battery")
+  if [ "" != "$raw_battery" ]; then
+    battery=$(printf "%3d%%" "$raw_battery")
+  fi
 
   echo "$cpu_temp$cpu_load$battery" > $cache_file
   # echo -e "HTTP/1.1 200 OK\n\n$cpu_temp $cpu_load" | nc -l -k -p 8080 -q 1;