[RedDevil]

Haven't forgotten, just had some busy days including a double birthday to attend/organize/endure.

I'll just drop a pic of where I'd like to drop my pack:



Under the aluminum shield is the OEM NiMH hybrid pack.
The black plastics are the vent channels of the forced battery cooling.

My parallel pack will not likely have active cooling - it should be at room temperature when I put it in, and it will probably just discharge at a not too high rate; nonetheless I'll drop in a temp sensor.

I run around these days without the boot floor (which is surprisingly heavy!) to this is pretty much what I see each day, save a blanket to cover it up and some small bags. Not having the floor and foam filler substantially enhances the cargo space

My parallel pack should be small enough to fit in the cavity behind the OEM battery cover.
I intend to fabricate a containing structure, with the necessary main switch and connectors.

I worried about what happens if I get rear ended and the cavity gets squeezed, pushing the extra cells into the OEM pack ruining both - but then the Fit Hybrid, which is technically identical, has a much shorter trunk and no cavity at all... so if that's not essential there I probably should not worry.
I'll leave some space unused just in case.