How will you manage/charge the LG battery? LiFePO4 or LiPo?
I don't have exact data, but based on known values for other Honda hybrids, the CR-Z may charge to a maximum of 134V UNDER HEAVY REGENERATIVE BRAKING. You'll want your Lithium pack max voltage to be well above this value.
Continually push a NiMH battery to 100% SoC, and you'll wear it out pretty quickly.
__________________
|