Plane: batt curr and remaining should be int16

ArduPlane/GCS_Mavlink.pde

@@ -213,8 +213,8 @@ static NOINLINE void send_extended_status1(mavlink_channel_t chan, uint16_t pack
         control_sensors_health &= ~(1<<5); // GPS unhealthy
     }
 
-    uint16_t battery_current = -1;
-    uint8_t battery_remaining = -1;
+    int16_t battery_current = -1;
+    int8_t battery_remaining = -1;
 
     if (battery.monitoring() == AP_BATT_MONITOR_VOLTAGE_AND_CURRENT) {
         battery_remaining = battery.capacity_remaining_pct();

ArduPlane/sensors.pde

@@ -44,10 +44,6 @@ static void zero_airspeed(void)
 // should be called at 10hz
 static void read_battery(void)
 {
-    if(battery.monitoring() == AP_BATT_MONITOR_DISABLED) {
-        return;
-    }
-
     battery.read();
 
     if (!usb_connected && battery.exhausted(g.fs_batt_voltage, g.fs_batt_mah)) {