How to keep user login in to system and logout only after user clicks on logout button?

I am using custom implementation of microsoft asp.net identity because i have custom tables that is why i have given custom implementation of all my methods .

Problem is when user logins then after 10 - 15 minutes login user session gets expired but what i want is unless user logs out i want to keep user login in to the system.

public partial class Startup
    {
        public void ConfigureAuth(IAppBuilder app)
        {
            app.CreatePerOwinContext(ApplicationDbContext.Create);
            app.CreatePerOwinContext<ApplicationUserManager>(ApplicationUserManager.Create);
            app.CreatePerOwinContext<ApplicationSignInManager>(ApplicationSignInManager.Create);
            app.UseCookieAuthentication(new CookieAuthenticationOptions
            {
                AuthenticationType = DefaultAuthenticationTypes.ApplicationCookie,
                LoginPath = new PathString("/Account/Login"),
                Provider = new CookieAuthenticationProvider
                {
                    OnValidateIdentity = SecurityStampValidator.OnValidateIdentity<ApplicationUserManager, ApplicationUser>(
                        validateInterval: TimeSpan.FromMinutes(30),
                        regenerateIdentity: (manager, user) => user.GenerateUserIdentityAsync(manager))
                }
            });            
            app.UseExternalSignInCookie(DefaultAuthenticationTypes.ExternalCookie);
            app.UseTwoFactorSignInCookie(DefaultAuthenticationTypes.TwoFactorCookie, TimeSpan.FromMinutes(5));
        }
    }

[Authorize]
    public class AccountController : Controller
    {
        public AccountController()
            : this(new UserManager<UserModel>(new UserStore()))
        {
        }

        public AccountController(UserManager<UserModel> userManager)
        {
            UserManager = userManager;
        }
        public UserManager<UserModel> UserManager { get; private set; }

         [HttpPost]
        [AllowAnonymous]
        [ValidateAntiForgeryToken]
        public async Task<ActionResult> Login(string email, string password, bool rememberMe = false, string returnUrl = null)
        {
            if (ModelState.IsValid)
            {
                var user = UserManager.Find(email, password);

                if (user != null)
                {
                    await SignInAsync(user, rememberMe);
                    return RedirectToLocal(returnUrl);
                }
                else
                {
                    ModelState.AddModelError("", "Invalid username or password.");
                }
            }
            return View();
        }

        private async Task SignInAsync(UserModel user, bool isPersistent)
        {
            var identity = await UserManager.CreateIdentityAsync(user, DefaultAuthenticationTypes.ApplicationCookie);
            identity.AddClaim(new Claim("FullName", user.FirstName + " " + user.LastName));
            identity.AddClaim(new Claim("Email", user.Email));
            identity.AddClaim(new Claim("Role", user.Role));
            AuthenticationManager.SignIn(new AuthenticationProperties() { IsPersistent = isPersistent, ExpiresUtc = DateTime.UtcNow.AddDays(7) }, identity);
        }

 private IAuthenticationManager AuthenticationManager
        {
            get
            {
                return HttpContext.GetOwinContext().Authentication;
            }
        }
    }

<system.web>
    <authentication mode="None" />
    <compilation debug="true" targetFramework="4.5" />
    <httpRuntime targetFramework="4.5" />
  </system.web>
  <system.webServer>
    <modules>
      <remove name="FormsAuthentication" />
    </modules>
  </system.webServer>

Now in this below line i have given 7 days of expiry time but still sessions gets expires in 10 - 15 minutes:

AuthenticationManager.SignIn(new AuthenticationProperties() { IsPersistent = isPersistent, ExpiresUtc = DateTime.UtcNow.AddDays(7) }, identity);

Here in my below question you will find my but for keeping this question small i am not putting that code here:

UserModel and UserStore

:I have completely ruled out so now below code is useless for me and i think because of this my cookie gets expired i guess(still i am not sure):

public void ConfigureAuth(IAppBuilder app)
        {
            app.CreatePerOwinContext(ApplicationDbContext.Create);
            app.CreatePerOwinContext<ApplicationUserManager>(ApplicationUserManager.Create);
            app.CreatePerOwinContext<ApplicationSignInManager>(ApplicationSignInManager.Create);
            app.UseCookieAuthentication(new CookieAuthenticationOptions
            {
                AuthenticationType = DefaultAuthenticationTypes.ApplicationCookie,
                LoginPath = new PathString("/Account/Login"),
                Provider = new CookieAuthenticationProvider
                {
                    OnValidateIdentity = SecurityStampValidator.OnValidateIdentity<ApplicationUserManager, ApplicationUser>(
                        validateInterval: TimeSpan.FromMinutes(30),
                        regenerateIdentity: (manager, user) => user.GenerateUserIdentityAsync(manager))
                }
            });            
 }

call then nothing happens in case of session expires but when i refresh my whole page then user is redirected to login page but till then how user will know what is happening if user doesnot refresh the page.