The "Death By [No] Battery" List

[Steve Simpkin]

I would add the Spice models (HP-31, 32, 33, 34, 37, 38) to the list of do not use on AC power without the batteries installed. As Harold notes, they may not always be damaged by doing this but the Owner's Handbooks for these models state:
"Note: Do not attempt to operate the calculator from an ac line with the battery pack removed."