First, a little disclaimer... I'm not a mechanic. I just like to work on my own cars and save as much money as I can. Like a lot of you, I don't have a lot to go around so I have to make the best use of it I can. In this video, I'll be replacing the Auxiliary battery for the first time in my 2015 Volvo S60 2.0 Drive E. The Auxiliary battery runs all the systems in the car while it's at a stop and the engine is off. It helps take the strain off the starter battery. Not sure why Volvo decided this was needed. A lot of other cars out there made do with just one battery and never have any troubles, so this just in my opinion ads complexity to a system that doesn't need it. It is what it is though, and like any battery, they go bad over time. I ended up using an almost identically spec battery by Mighty Max, available here https://www.amazon.com/dp/B00P2Q9J7C?... for $30, vs the Volvo branded one for $100. Initial thoughts are that it looks like it'll work just like the original, but only time will tell. I'll test it on my car so you don't have to, and if I do have issues, I can guarantee you'll hear all about it.