I know you can use three Energizer 357 type cells, but does anyone know what was shipped with the first 12c models?

Curiosity and a cat have a meeting later.

According to the handbook dated August 1981, various batteries were recommended replacements:

Alkaline:

Eveready A76, UCAR A76, RAY-O-VAC RW82, National or Panasonic LR44

Silver-Oxide:

Eveready 357, UCAR 357, RAY-O-VAC RS76 or RW42, Duracell MS76

Silver-Oxide will last more than twice as long as Alkaline

Edited: 21 Apr 2011, 12:59 p.m.

but that doesn't answer the question. (And Gene already knows that list by heart :-)

I have to query my crainial database for memory of the 1st time I opened the battery compartment of my 11c, to see if I remember the brand, and then extrapolate that to the 12c.

Something jogs in me that they were alkaline. But how could that be a reliable memory? Too long ago and not an important thing to remember. I do remember being interested in the Silver for two reasons: one being the longer life, and the other being the interesting fact that alkalines go dead more gracefully.

Doesn't it stand to reason that the original batteries would have been the same as one of the recommended replacements? I seem to recall when I changed the original batteries in my HP-15c that they were A76 alkalines.

A76's from Eveready with the small Union Carbide logo stamped on them.

Edited: 21 Apr 2011, 1:47 p.m.

Gene:

I have three HP-11C's. Two have Kodak KA76's in them -- not even on the list. One of the two is S/N 2217A03623 which is an early enough unit to have the bug. I am fairly sure that I have never replaced the cells as I have hardly ever used it. The other has MS76 Silver Oxide cells.

Thanks all!

Corroborating Evidence: i believe it was union carbide in my 11c too.