Не работает таймер если закрыть страницы или перейти на другую

var newDate2, 
  intervalId2; 
if (localStorage["timer_upd"]) { 
  newDate2 = new Date(localStorage["timer_upd"]); 
  timerr(); 
  intervalId2 = setInterval(timerr, 15000); 
} 
 
function updFuel(tmr) { 
  newDate2 = Date.now() + 60 * tmr; 
  timerr(); 
  if (!intervalId2) intervalId2 = setInterval(timerr, 15000); 
  localStorage["timer_upd"] = new Date(newDate2).toISOString(); 
  // localStorage["span"] = true; 
} 
 
function timerr() { 
  var now2 = Date.now(), 
    rest1 = newDate2 >= now2 ? Math.round((newDate2 - now2) / 1000) * 1000 : 0, 
    s1 = ""; 
  if (!rest1) { 
    clearInterval(intervalId2); 
    intervalId2 = null; 
    localStorage.removeItem("timer_upd"); 
    // localStorage.removeItem("span"); 
  } else { 
    var rest3 = rest1 % 3600000; 
    let hh1 = (rest1 - rest3) / 3600000; 
    rest1 = rest3; 
 
    rest3 = rest1 % 60000; 
    let mm1 = (rest1 - rest3) / 60000; 
    rest1 = rest3; 
 
    rest3 = rest1 % 1000; 
    let ss1 = (rest1 - rest3) / 1000; 
    let ms1 = rest3; 
  } 
  $('.info').remove(); 
  $.ajax({ 
    type: 'POST', 
    url: '../fieldfunc', 
    data: { 
      tract_pl_udt: localStorage.getItem("selecttract"), 
      fuel_pl_upd: 1 
    }, 
    success: function(result) { 
      result = JSON.parse(result); 
      $('.updinfo').append('<p class="info" style="margin-bottom: 10px;"> Плуг: ' + localStorage.getItem("selectplow") + '<br>\ 
        				Трактор: ' + result[0].title + '<br>\ 
        				Топлива в баке: ' + result[0].fuel_now + ' литров</p>'); 
      if (result[0].fuel_now == 0) { 
        localStorage.removeItem("timer"); 
        localStorage.removeItem("timer_upd"); 
        localStorage.removeItem("span"); 
        localStorage.removeItem("selecttract"); 
        localStorage.removeItem("selectplow"); 
        setTimeout(function() { 
          window.location.href = "../field"; 
        }, 1000); 
      } 
    } 
  }); 
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script> 
<button class="btn plowsbtn" onclick="updFuel(' + 37000 * $fz + ');">Вспахать</button>