I just bought a replacement battery (http://www.dvoltbatteries.com/index....emart&Itemid=1) from dvoltbatteries for my 03 f4i. do i need a battery tender or can i just plug the battery in and be ready to go.

 

There should be instructions included in the battery. Most batteries are NOT charged when you purchase them via mail-order. If you bought it from a dealership, there is a slight chance they will charge it up for you. Not all do, however.

I would throw it on a Battery Tender/Charger and let it sit overnight before installing.