I have a Dell Latitude 610 laptop which has a bad battery. I keep using it on electric power but I continually get "critical battery" popup balloons on the bottom right. Now the computer occasionally shuts down randomly or goes into Standby mode. I tried using it without the battery and it worked fine for awhile before shutting down. I thought using it without the battery would be OK?? Is it or not? Do I need to buy a new battery for it to operate properly? Thanks