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Please can anybody advise what battery lifetime I can typically expect from an HP-42S and an HP-27S? We bought two 'mint' HP-42S and HP-27S calculators via eBay earlier this year but the batteries seem to go dead after only about 1 month of light use.

Reason for asking is we also use an HP-14B and HP-32S for our nuclear consulting work, and the batteries seem to be going strong even after 12 months of daily usage.

Do the HP-42S and HP-27S calculators have much higher battery drain than the HP-14B and HP-32S or are the calculators probably going wonky? NB we are using 3 new Duracell 357/303 (SR44W) silver oxide button cells in each calculator.

Best wishes

Ian J


42s and 27s do have higher drain than the 32s and 14b. They are also sensitive to extra drain if you have an "appointment" set that keeps going off. But a month does seem short. How many times have you had to replace the batteries?

Thanks Bill. I inserted a set of fresh Duracells (new in packet) twice in the 27S and once in the 42S. I have just inserted a replacement set as an experimental trial just in case maybe it was caused by a bad batch of Duracells, but I have a feeling all is not well...

I suppose the main reason for posting the question was to find out whether short battery life is a relatively common problem with the 42s/27S or whether I have just been unlucky?


Ian J

Do your calculator disable the printer function, some function, like aview,view, will transmit the signal from IR eyes to printer,if you always run these program and you do not disable the printer function,it is one of reason to make the battery short life.

the following parts of program structure I always run







If I did not disable the printer (POFF) and I always use this program with this structure, the battery also need replace around 1-2 month

Edited: 4 Dec 2006, 10:02 a.m. after one or more responses were posted

Silver-oxide batteries will last much longer than just regular alkaline ones. Depending on how much I use the IR printer, I get about 18 to 24 months to a set of Silver-oxide. I have never used alkaline batteries in any calculator that uses the button type batteries so I can't give you a time frame for them.

My 11c manual states, "the batteries supplied with the calculator are alkaline, but silver-oxide batteries (which should last twice as long) can also be used." (LR44 or 357 respectively)

The other thing it talks about is the time remaining after low power indication. The silver oxide crash much faster (2 hours continuous program running, versus 15 minutes, aftet the * indicator comes on).

I know this is from a Voyager manual, but I think it gives good general information about the two types of batteries in common use.

Hi Ian,

Were all the batteries bought at the same time? They may just be old or a bad batch. I'd try buying some new batteries from a different manufacturer - Everyready, or ...

Just checked my HP-42S and I have Energizer 357 in it. They've been in it for over a year - light duty.

Also, as previously mentioned make sure you have POFF set in the printer menu. But if the printer was set on, you'd see the little print Icon in the display and probally notice a delay in the operations.


Thanks for all the suggestions, I'll cross my fingers and try them all out.

Best wishes

Ian J

Ian --

The HP-42S, HP-27S, HP-17B, and HP-17BII have an IR transmitter for use with an HP82240A/B printer. Each of these four calculators will transmit a print signal for every input if "TRACE" mode is set. TRACE is accessible under the PRINTER or PRINT menu as applicable. (You will see a printer annunciator flash, and experience a delay in operation while any print signal is transmitted.)

The HP-42S also provides a "master switch" for print signals -- "PRON" and "PROFF", which appear as "PON" and "POFF" under the PRINT menu. The other models do not have these functions. The user can allow printing by executing "PRON", or completely disable print signals by executing "PROFF".

The HP-27S, HP-17B, and HP-17BII also have a built-in clock that cannot be switched off. This will reduce battery life, but not to the extent that you are seeing.

Neither the HP-14B nor the HP-32S or HP-32SII have the printing or clock features, so their battery life should be quite long.

-- KS

Edited: 5 Dec 2006, 12:22 a.m. after one or more responses were posted

Thanks Karl,

Ian J

I think Chiu has the answer. You MUST disable the printing function when not in use, i.e. POFF. Otherwise your batteries are being used unnecessarly.