My Dell laptop battery is not charging, what is going on?

I have a Dell E6400 laptop. My AC adapter stopped working so I purchased a new one. It is an off-brand that included tips to fit 7 different laptops. The laptop works but the battery is not charging. Stays at 0%. Every time I turn it off, I have to re-boot the whole machine. Any suggestions? I think something needs to be re-set.