Kellyyhx,
i have been messing around with the ds scene for so long
yet to hear any fake DS console
what i had heard about is refurbish set
anyway, if the battery is not the problem? could it be the charger? thats the case for one of my friend
no matter how many times he changed the battery is always red light for him
so he concluded that was his charger..... and after changing his charger.. everything works

since you bought your DS 2-3 months ago... can you recall any nintendo stuff came with the box?
normally, an original DS should have some goodies from nintendo club (depends on the region)
not really the case..
infact one of the sellers has an account on LYN and i have been buying things from him

xbox360 and a couple of ps3 games
I still have the whole box content with me.
Only console and charger/adapter..
I've test it with my own charger. It doesn't work.