Bluetooth not work when using battery

Hi all,
I using the following code to control the On board LED by the Bluetooth ,when using USB cable to power the code below is work .but when i unplug the USB and using battery to power up is nothing happen .

//Setup the BT Serial
function onInit() { 
  Serial1.setup(9600);
}

var trace = ""; 
Serial1.on('data', function (data) {

	trace = +data;
 digitalWrite(LED3,0);

if(trace  == "1" ){
  digitalWrite(LED2,1);
}
  
if(trace == "0" ){
  digitalWrite(LED2,0);
}
  
});

save();