Really remove Devises timeoutable...

... and force it to really remember the session by a hidden field.

app/models/user.rb

@@ -18,8 +18,8 @@ class User < ActiveRecord::Base
 
   devise :database_authenticatable, :registerable,
          :recoverable, :rememberable, :trackable, :validatable,
-         :timeoutable, :token_authenticatable, :lockable,
-         :lock_strategy => :none, :unlock_strategy => :none
+         :token_authenticatable, :lockable, :lock_strategy => :none,
+         :unlock_strategy => :none
 
   before_validation :strip_and_downcase_username
   before_validation :set_current_language, :on => :create

app/views/sessions/new.html.erb

@@ -30,6 +30,7 @@
           </div>
         </fieldset>
 
+        <%= f.hidden_field :remember_me, :value => 1 %>
         <%= f.submit t('devise.sessions.new.sign_in'), :class => "new-btn" %>
   <% end %>