The stock (OEM) battery is type MF 68 AH (600 CCA), which isn't readily
available in the USA, and most battery companies don't list a
replacement battery. The notable exception is Interstate, which
specifies type 24T.
After considerable research, I settled on the EverStart MAXX-24FN, sold
exclusively by WalMart for $62.28 with free installation.
Specifications: 700 CCA, 875 cranking amps at 32 degrees F. Warranty:
3 years free replacement; 9 years prorated.
EverStart gets top ratings. It's distributed by Johnson Controls, which
also makes several other top brands.
The EverStart battery fit perfectly with just a bit of trimming of the
stock battery heat shield cover with scissors.
Significant upgrade from the stock battery. Highly recommended.

Signature
Best regards,
John Navas
hyundaitech - 15 Aug 2006 00:31 GMT
Sounds like a good battery, John. It's got similar specs to the Hyundai
branded Interstate replacement, a warranty that's more than twice as long,
and about 2/3 the price tag. Good find.