Toshiba Satellite 4030CDT laptop battery question

Hey guys,
Anyone have this laptop or a similar one and know if I can upgrade the battery? I think it lasts for 2 hours fully charaged, its quite an old laptop and I thought there might be a longer lasting battery availible. All the websites I look at that sell these batteries don't mention how many hours they last...
Cheers

 

i dont know how to explain it really my dad was helping me with it once. if u know the watt hours of the battry and the watts that ur computer uses u can do the math and get the estimnated time. Liky my laptop has a ~90 watt battry and uses 30 watts an hour so that abuot 3 hours. BUt it all depends on the usage