Twenty-three year battery life in 15c?

[sb]

I have an HP-15c that I purchased in 1983. To the best of my recollection I have never changed the batteries, and it's still running on its originals. I have a friend who says the same thing about his HP-15c.

Is this at all possible? I've used it very little in the past fifteen years, but I do use it on occasion.

[bill platt]

Yes it is possible.

My wife has a Sharp Elsi-mate with an aa (aaa?_) cell that is still good after over 20 years.

[Richard Garner]

Yes, this is very possible. I owned a 15C for 20 year and only changed the batteries once. That was only because the batteries in my 42S were low and I hadn't used the 15C in about 5 years so I swapped the batteries. The 42S ran for another year before replacing them. One thing to note, they were Silver Oxide batteries.

[David Smith]

You should change them regulalrly even if they are still good. Otherwise you wake up one day with a machine damaged by leaking batteries.

[John Smitherman]

Quote:

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You should change them regulalrly even if they are still good. Otherwise you wake up one day with a machine damaged by leaking batteries.

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You make an important point about routine calculator maintenance. One action that I have taken to address this issue is to open up the battery compartment of my calculators and other electronic devices yearly to inspect the condition of the batteries. I have a 15c running on 19 year old batteries.

Regards,

John

[bill platt]

Two general questions.

1. Has anybody ever seen a *Silver* cell leak (type 357)?

2. How can my wife's Elsi-mate run on a AAA for 20 years without leaking? Were there non-alk non-carbon AAA cells?

[John Limpert]

I've never seen a leaking silver oxide cell.

I've used lithium AA cells. According to Google, they also make lithium AAA cells.

[David Smith]

ALL cells will eventually leak. ALL seals will eventually fail. Particularly in a mass produced $1 consumer item.

[Palmer O. Hanson, Jr.]

I purchased my HP-11C in December 1982. The batteries have never been changed. It still runs properly. I removed the batteries. The no-load output voltage has dropped to 1.4 volts.

[John Kercheval]

Yes, that is possible. A colleague of mine has a 41CV and has not changed the batteries since 1984.

John Kercheval
Washington, DC