"I am curious as to why the big battery as opposed to the Odyssey PC680?"Somebody GAVE me two of them!! Friend of mine at the airport flew a Turboprop Lancair for awhile. It has a 24V electrical system, and uses two of these in series. They are replaced yearly as a part of routine maintenance. Being a "Hobby" airplane, they only had 20 or so starts on them. I've had them on "Battery Tenders" for awhile now. The one in the picture was capacity checked when I was making the measurements for the rack, & Passed with flying colors.
Here's my charger/loadbank:
I charged it up, and pulled 20A out of it for two hours, and still had 12.2 VDC. I hope it survives until the car runs on it's on!!