Cordless drill battery replacements

[61_FL_Apache]

I have a 12V Dewalt drill that has been one of the best. I bought it in 2004 and replaced the batteries in 2008. Now I need another set.

I have been looking at ebay for more. I see the Dewalt name batteries for some big money and no-name ones for about half the price..

My concern is, are the name brand batteries still being name or they NOS batteries that have been on the shelf for 10 years?

The set I bought in 08 lasted longer than the original set from 04.

One of my batteries from 08 is still in good shape, but the other one is toast.

Thanks for any input you may have!