Yes, BALANCES is a Scrabble word!

Letter values in Scrabble US: B 3, A 1, L 1, A 1, N 1, C 3, E 1, S 1.

Is it a valid word?

BALANCES is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

a state of equilibrium
equality between the totals of the credit and debit sides of an account
harmonious arrangement or relation of parts or elements within a whole (as in a design)
equality of distribution
something left after other parts have been taken away
the difference between the totals of the credit and debit sides of an account
(astrology) a person who is born while the sun is in Libra
the seventh sign of the zodiac; the sun is in this sign from about September 23 to October 22
(mathematics) an attribute of a shape or relation; exact reflection of form on opposite sides of a dividing line or plane
a weight that balances another weight
a wheel that regulates the rate of movement in a machine; especially a wheel oscillating against the hairspring of a timepiece to regulate its beat
a scale for weighing; depends on pull of gravity

Also: libra the balance, libra the scales, balance wheel.

Not playable in Scrabble US: EQUILIBRIZE, EQUILIBRISE.