I recently saw a message on my 2017 Prius Prime Premium warning me that my 12v battery charge was low. Never saw that before. I was fooling around with a Garmin GPS in the cabin, but I was in "ready" mode and the aux battery should have been charging. The charge port may have been connected. Tested the battery and it was at less than 50% charge. Charged it and tested the CCA. The original battery is rated at 295 CCA and tested at 245 CCA in a 65 deg. setting. Probably would be fine for a while yet, but it is almost 7 years old, so... Started shopping online for the proper replacement: H4, LN1, 140R... Found suitable batteries at O'Reilly's, AutoZone, Toyota and Batteries Plus. Long story short, the best solution for me this time was Batteries Plus. They do not carry the 140R, but they do stock a Duracell Ultra SLI121R which has the same dimensions except the height is .6" taller. The additional height didn't affect the installation at all. Slipped in there like a green wiener. The CCA rating is 550 and my new battery tests at 795 CCA. 24 month full replacement warranty. Added bonus, they lent me a memory saver device which plugged into the OBD2 port, so no resetting required - nice. They always offer a 10% discount if you order and pay online and then pick it up at the store. Today I found a "SAVE20" code instead that took 20% off of the normal price of $182.99. Score! All said and done after getting the core refund ($22.00), my final price in NC including 7.25% tax was $157.00. I know that there are differences between cranking and deep-cycle designs and the way the aux battery is used, a deep-cycle design may be better, but this is a simple flooded lead acid battery, so I don't think it matters. I have no connection to this vendor, just thought I would share my findings. Maybe they'll help somebody.