Does a constantly running fan effect battery life at all?

I have a Dell Latitude E6410 which has the fan constantly running. It has a small connecter soldered so it keeps continually running. This results in a cooler machine but does this effect my battery life at all? I purchased a new battery last August but I'm barely getting an hour use out of it. I'm considering getting a new one but I don't know it it will help. Thoughts?

2010 Dell Latitude E6410

i7 processor, 8gb RAM