These guys have them for the Fusion Hybrids, but not the energi (yet):
I just got a response from greentecauto... they are "working on" a version for the energi and are in a pilot program to figure out the mileage per charge on their new version. No word on when it will be available. I didn't ask if it was possible to be part of the pilot program, but I'm not currently in need of a replacement. If you are, it might be worth asking.
Based on their fusion hybrid battery prices, I'd bet an energi version would be north of $6000.