So far the highest-rated AH battery advertised that I’ve been able to find for the Toyota Prius is 45AH. The Optima Yellow Top battery is only 38AH. We found an 85AH battery that fits in the stock/OEM battery location!
Special thanks to @priuscamping for the pictures and being the guinea pig for this fitting. After installing an 85AH battery as my second battery, we realized the larger battery would fit the Toyota Prius where the original battery is located.
What is the benefit you ask? More Amp Hours allows you to have your car off and use your battery for a lot longer than a 45AH battery.
So if it’s time for you to replace your battery, I would recommend getting this 85AH battery!