Move all cards to the Foundations.
Free Cell is played with one deck. All cards are dealt at the start of the game. To compensate for this there are 4 free cells which can hold any - and just one - card.
Piles build down by alternate color, and an empty space can be filled with any card or sequence.
The number of cards you can move as a sequence is restricted by the number of free cells - the number of free cells required is the same as if you would make an equivalent sequence of moves with single cards.