I had a same problem on my different model of satellite too. I spent $150 once to fix the charging problem. After about a year i started experiencing the same problem so i researched it on the web and found out that there has been a law suit filed against Toshiba for certain models for the same problem. So i simply call the nearest repair center and they repaired it for absolutely free. It looks like A70 is covered under that settlement program.
check this out:
http://www.a70m30xsettlement.com/

Hope this will help.