How can I test the battery of my Toshiba NB505? The battery charges on hookup for 4-10 seconds then stops. I lost the charger cord & ordered another. This 2nd cord has worked fine for about a year. Thought it might be the plug socket but then everything started working fine after we took the battery out & bottom off the netbook & put it back together. Worked fine for several weeks, then suddenly stopped again. Thanks in advance for any suggestions.