The reserve capacity of a battery is what makes the difference.
Do you have or have you looked up the window sticker of your vehicle?
This will tell you if you have a premium sound system or heavier duty charging system.


I've only owned earlier V70's and all had lead acid batteries in either the H6 or H8 sizes. My '99 had a group 48 battery which is essentially an H6.

I don't know what Volvo put into the 2008+ vehicles. A quick look at the RA catalog showed 150 & 180 amp alternators but batteries came in just the H6/G48 sizes (essentially the same size), all of the same capacity.

Be aware that some people -and shops- are smitten with AGM batteries. If your vehicle came with a lead acid battery I'd stick with that. AGM batteries have a different charging profile where damage can be done to them as they approach full charge.