I live in Connecticut; have a 2005 Prius with 187,000 miles. The 12 volt battery has never given me a problem but its 7 years old so I believe I am on barrowed time and winter is approaching. I know it's a vented battery and the dealer cost was around $250. To me this is very expensive for a small 12 volt battery. 1) Does anyone sell a vented aftermarket battery? 2) Has anyone bought a dealer battery over the internet at a much better price? All advice is appreciated.