commander: Warn at 18 and 9% battery remaining instead of 25 and 10% to not trigger the warning too early (at 50%) as it was before

src/modules/commander/commander.cpp

@@ -1276,13 +1276,13 @@ int commander_thread_main(int argc, char *argv[])
 		}
 
 		/* if battery voltage is getting lower, warn using buzzer, etc. */
-		if (status.condition_battery_voltage_valid && status.battery_remaining < 0.25f && !low_battery_voltage_actions_done) {
+		if (status.condition_battery_voltage_valid && status.battery_remaining < 0.18f && !low_battery_voltage_actions_done) {
 			low_battery_voltage_actions_done = true;
 			mavlink_log_critical(mavlink_fd, "LOW BATTERY, RETURN TO LAND ADVISED");
 			status.battery_warning = VEHICLE_BATTERY_WARNING_LOW;
 			status_changed = true;
 
-		} else if (status.condition_battery_voltage_valid && status.battery_remaining < 0.1f && !critical_battery_voltage_actions_done && low_battery_voltage_actions_done) {
+		} else if (status.condition_battery_voltage_valid && status.battery_remaining < 0.9f && !critical_battery_voltage_actions_done && low_battery_voltage_actions_done) {
 			/* critical battery voltage, this is rather an emergency, change state machine */
 			critical_battery_voltage_actions_done = true;
 			mavlink_log_emergency(mavlink_fd, "CRITICAL BATTERY, LAND IMMEDIATELY");