my experience installing elearnaid's 12v Optima battery

I just replaced my OEM 12v auxiliary battery with the elearnaid Optima D51 that several folks on PriusChat have recommended.
I am not very experienced at working on cars, so it took me two hours to do the job, but I am happy to report that I was successful! I had previously replaced conventional batteries once or twice on my trusty old Subaru, which is certainly a lot easier to do.

Elearnaid provides detailed step by step instructions which, for me, were essential and generally quite clear. I had only two problems, both minor: even though I hooked up a 12 volt 7ah backup battery (which I had first charged to full strength) to save my settings using the post provided in the engine compartment , most were not saved, I don't know why: I had to reset the clock, the radio presets, and once again disable the annoying backup beep. The electric windows, though, seem to work ok.
The other minor hiccup: I was not able to unhook the white connector from the brake assembly unit located in front of the 12v battery. For some reason it would not come out. So I just unbolted that unit and moved it aside with the white connector still attached. Not a problem.
As some others have said, the bolt on the positive terminal that must be removed to disconnect the fuse assembly is indeed very hard to take off, but one can do it with a little tenacity. Others have also mentioned that it's hard to remove the bolt that connects the square black plastic vent above the 12v to the outside wall. Yes indeed, it's hard to get to it to take it off, and harder still to replace it after the new battery has been installed. But if I can do it, you can too!

I am going to keep my OEM battery as a backup because, actually, it has never given me any problems. My car has never failed to start.But I have had the car four years, and like Dr. Fusco, I decided to replace the auxiliary battery before it started acting up. And I was impressed when I read about the advantages of the Optima over the OEM battery.

Thanks again to all who write in to answer the questions of those of us who are not as Prius savvy. That's what gave me the courage to tackle this job.