Someone educate me on the proper way to connect batteries in parallel.

*most* images look like this:
Click image for larger version.  Name: Parallel 1.gif  Views: 143  Size: 11.3 KB  ID: 80271

Where the positive is coming off of battery 1 and the negative is coming off of battery 2.


Some images show the positive and negative cables both attached to Battery 1:
Click image for larger version.  Name: Parallel 2.jpg  Views: 141  Size: 21.5 KB  ID: 80272



It's been a long time since I last took any sort of electrical engineering class but I thought the first method was correct. However, now I can't quite figure out why it matters.

Help me out here. Does it matter? Which way is correct?