I don't think we have hard confirmation, but the 2012 bikes use EIG C020 pouch cells. The pre-2012 bikes all used molicel cylindrical cells.
EIG rates the C020 cells at -30C to 55C (131F) storage and operation.
In the 2012 manual Zero claims the power pack should be used only in the range of -7C (20F) to 71C (160F), and the BMS will disable operation outside this range.
Why the temperature discrepancies?
It's possible on the lower end that other electronics on the bike are suitable only to 20F. It's also possible the batteries give truly abysmal performance below 20F, but I'd still like the option to use the bike in that case..
On the high end, the 55C rating appears to be a 1 month storage temperature (PDF link
). Zero may have performed durability testing of the batteries above that temperature, or they may be suitable for limited duration storage above that temperature. It may be worth following up with Zero directly to see why the discrepancies exist.
131F internal temperature is still probably good for about 110F ambient. If Zero's specs are incorrect, then you would want to keep the bike shaded above that temperature.