using a second battery as backup

I just purchased a second battery for my audio system. The subject may look like an old topic, but my question is different. What I want to know is can I use this second battery to start my car, in the event of a battery failure? Like for example last week, I left my lights on(long story- from theft of my GPS system etc etc)on and car battery died. I was wondering if I had the second battery (for audio) via an isolator, I could use that to start my car. Battery I purchased is a stinger power2 800 amp battery. Pac2 isolator. Also I am not sure how to connect the battery to cables, since the battery came with screws and springs and round bolts. Any answers would be appreciated as always. Mark

You can also use your neighbor's car with jumper cables.  That seems like a strange reason to purchase a second battery and isolator.  And I think a slow walk through the hardware store will solve the issue of connectivity.  And good to see you again, markcars!  Been a long time!Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

As my first sentence says "I just purchased a second battery for my audio system" my main reason was for my audio system. However, I had this incidence last week where my battery was discharged from having the door ajar for about 48 hours. That is when I realised my newly purchased battery might help me start the car in case of such an incidence. Reason why I think it should work is the isolator should switch to "on" position when I turn the ignition on, thereby connecting the second battery to the main battery. I just wanted to know if anyone has ever done this before and if there were any concerns. Also do both batteries need to be of the exact same type? I think no but I might be wrong. About the connectivity, I went to stinger's website and found that I already have the necessary hardware, so I am happy. Just need some warm weather to do this battery stuff and install the new focal and morel speakers I purchased.

Yes, that'll work fine. They don't have to be the same type of battery.  Be sure to fuse the secondary battery as well.My ex once told me I have a perfect face for radio.