diff --git a/config.h b/config.h
index d805331..33d0cd5 100644
--- a/config.h
+++ b/config.h
@@ -64,6 +64,8 @@ static const char unknown_str[] = "n/a";
  * wifi_perc           WiFi signal in percent          interface name (wlan0)
  */
 static const struct arg args[] = {
-	/* function format          argument */
-	{ datetime, "%s",           "%F %T" },
+	/* function     format          argument */
+	{ datetime,     "%s",           "%F %T" },
+	{ battery_perc, "%s%%",         "BAT0"},
+	{ battery_perc, "%s%%",         "BAT1"},
 };