Hi all...wondering if possible to add a second upper used HV to extend range in my 2012 FFE. Has anyone attempted or researched this? I would think it would be fairly easy to do and put it in back seat area as I don't use the back seat. Currently my car has 85,000 miles on it and I believe has lost 10 to 15% of the original range due to battery degradation. I would love to get over a hundred miles of range rather than the 65 to 70 I currently get. I saw an upper battery pack for $1,800 used on the internet. Thinking this would be a better option than total battery replacement. Any help or technical information would be appreciated. Thank you!