I need a new battery. Mine is old and beginning to fail. What kind/ type should I replace the orig with? Same specs? Parts store? There is a Sears near by, I could get a Die Hard. No dealers close to me.

Something else to think about when selecting battery (besides price) is hydrogen gas venting. As a safety feature to prevent H2 gas explosion in the spare tire compartment, Volvo has a hydrogen gas vent tube that carries H2 gas outside the vehicle.

Interstate and others sell a "sealed" battery with no vent port. However, these batteries have an internal pressure relief valve, and if conditions build up pressure in battery to 2-3 psi, this valve will dump hydrogen gas into the spare tire compartment. Any spark will ignite an explosion.

My mother lost hearing in one ear from a car battery hydrogen explosion. There is no warning.

You have 2 choices, the H6 or the H8. The H8 is larger physically but is reputed to last longer. Walmart has them.

Your battery goes in the trunk area? Have them install it for you, should be freebe. Watch them, you want to make sure the vent tube is aligned properly and the hold down is still there.
--
Keeping it running is better than buying new

You don't need to purchase a volvo brand battery. Sears or other outlets should have a battery compatible with your car. Two or three companies make almost all the batteries for all cars / retailers. You can check on-line or with the retailer and it may vary based on model and year. I purchased a battery for my xc70 at Menards and a battery for the 940 at wal-mart.

I've gotten Interstate consistently, because of great warranty -had many replacements free. Slightly less generous than the early years but still good. Right now I have a Die Hard from previous owner, but will likely switch back when the time comes. I went to the Brooklyn store, But would go here if I were you (Sunnyside) https://www.interstatebatteries.com/locations/all-battery-center-sunnyside-ny
--
Farewell 'black manta' ('97 850) Hello 'rocket sled' ('06 V70R)

Last battery I picked up was from Costco. Though branded as Kirkland, it was manufactured by Johnson Controls. As another stated, J.C. makes batteries for many labels.

It's my understanding that Costco now carries Interstate batteries. I haven't checked lately.