[PSUBS-MAILIST] Series-Parallel OR Parallel-Series

I have eight, 12 volt batteries. Two are connected in parallel for the starter and other 12 volt stuff and the other six need to be connected in either Series-Parallel or Parallel-Series. To me, Series-Parallel is connecting 3 batteries in series and then connect that in parallel to the other 3 batteries that are also connected in series.

A picture will help: http://www.submarineboat.com/sub/images/battery.jpg

I want to connect them in Series-Parallel because its less wire and fewer connectors with two cables, however the tech at www.dualpro.com where I purchased my Three Bank Pro Chargers told be to connect them in parallel as pairs and then connect the pairs in series, or what I think should be referred to as Parallel-Series. He was unyielding on his view but also unwilling or unable to explain why.

So is there any difference between Series-Parallel and Parallel-Series?

And all the tech would tell me about how the Pro3 charger worked, was that it electronically isolated the batteries so that disconnects were not needed. Can someone please explain that bit of magic? The Three Bank Pro3 charger has 6 leads or a positive and negative for each of 3 batteries. I have 2 of these Three Bank Pro3 chargers so I can charge all 6 batteries in the 36 volt supply.

Thanks for the help.
Doug Jackson
Tulsa, OK
www.submarineboat.com