When I started on the front hub battery replacement project, I had planned on just replacing the battery in the Tidalforce iO since that pack was starting to act flakey and not always be ready for riding when my wife and I were. However, after working on it a while and brainstorming, I realized that I could configure my other front hub battery for my S-750 so that the front hub battery would be half of a xxV pack. I could fit half the pack inside the hub and the other half either in the frame or below the downtube.
The iO version would be 2S1P consisting of two Zippy Flightmax 5S 8000mAH packs for 37V 8AH.
The S-750 version would be 4S1P consisting of 4 Zippy Flightmax 6S 8000mAH packs for 88.8V 8AH.
The front hub on the S-750 would add some significant mass to the front wheel which feels very light and feathery now with the Bosch Fat Packs over the back wheel and making it top and back heavy.