There is plentiful information about the 12VDC AUX battery if you use the search function, but the best available replacement source will be an Optima Yellow top.
There is not universal agreement that the Optima is the best battery, especially not when you consider price. Shop local dealers, auto parts stores and battery shops by phone.......for a brand name AGM type sealed battery. The prices likely won't really vary that much. Beware of a low-ball price; it will NOT really be a bargain.
That is not news. Batteries and tires have come with a pro-rated warranty for ......... pretty much forever.
There's also the Exide AGM for the Prius: Amazon.com: Exide Edge FP-AGM51JIS Flat Plate AGM Sealed Automotive Battery: Automotive
There is an Exide for the prius, I see it with anther Part number as well. Exide AGM Car Battery (Group S46B24R)
