I replaced my battery and it feels like at times I am losing Power what could it be?

Hello, this doesn't sound like it could have anything to do with a battery replacement. Your vehicle seems to have some slipping occurring within the automatic transmission. Assuming, of course, that it's an automatic. You'll need to have some testing performed to find out what is going on. A Ford IDS diagnostic tool or equivalent, along with a workshop manual and other testing equipment is needed. www.repairpal.com/repair-shops