The phrase "a very different battle" is correct and usable in written English.
You can use it to describe a situation or conflict that is significantly distinct from another, often in a metaphorical sense.
Example: "While the previous negotiations were challenging, this time we are facing a very different battle with the new regulations."
Alternatives: "a completely different struggle" or "a notably distinct conflict".
As the two enter the final days of their campaigns, they face very different battles: Mr. Corzine, a Democrat, has dismal approval ratings and is in a close race, fighting to avoid becoming a one-term governor.
It is a cliched thing to say, but true nonetheless, that the Lib Dems must fight very different battles when they take on the Tories in southern seats as opposed to when they wage war against Labour in the northern cities.
We fight very different battles in business.
This intrepid history of the American Revolution shifts the focus from the rebellious thirteen colonies to the Gulf Coast and the Mississippi valley, where Native Americans, African slaves, and Spanish, French, and British colonials were fighting very different battles.
There are two very different battles going on between Microsoft and Yahoo.
Don Quixote has survived independently of Cervantes and has been reenlisted through the centuries, each time to fight new and very different battles.
But the lives of these three will collide in unexpected ways, as each fights a very different and personal battle.
Meanwhile, over Bethlehem way, a young shepherd is engaged in a very different sort of battle.
Here we have a very different depiction of the battle between the sexes with this Ukrainian exhibition, titled, "Gender in Izolyatsia: Seams of Patriarchy and Identity Tailoring," which takes place in a former insulation materials factory.
Since he moved to a ranch in the foothills of the Canadian Rockies with his wife 18 years ago, Donald Sutherland has been waging a fierce battle against a very different kind of pest -- gophers.
