Best answer by Adzdalton
The S10 comes with two variants of internal storage. 128GB and 512GB.
However the S10 plus will be the first phone to offer an aditional 1TB variant.
Both of these will accept up to 512GB micro SD of course too.
That's leading the way in phone storage at the moment.
As for the battery life, the S10 model comes with a 3400 mAh battery which is pretty decent.
The S10 plus comes with a humongous 4100 mAh battery.
I would say thats a considerable upgrade from the J5 you're used to.
Hope that helps :)