PDP-8 /e/f/m memory

[Don]

O. Sharp wrote:
>>> I have always HATED the idea of a battery where one wasn't absolutely
>>> needed.  They have a nasty tendency to go south when you can least afford
>>> it--and they can leak or explode.
>> That's why using a *regular* battery/cell instead of something
>> "designed for battery backup" (e.g., Li coin cells, etc.).
> [...]
>> Unless you can make a battery application last A VERY LONG TIME
>> (not just a LONG time since those are the cases where you get
>> screwed because you have forgotten about the battery that
>> you replaced 1 or 2 years ago... *but*, if you replaced it
>> *10* years ago you don't mind -- as much -- when it dies
>> after that long of a service life) it will frustrate users.
> 
> Er, I don't think it's the longevity of the battery _power_ which is at 
> issue here; it's the physical longevity of the battery itself.
> 
> I have mini-Maglites in my toolkit - three of 'em, and they all get use; I 
> work in the dark a great deal, but that's another story * - and recently 
> had the unpleasant surprise of having one of the "regular" batteries 
> corrode and die (and the batteries had been replaced less than a month 
> earlier). This did an _astonishingly_ effective job of destroying the 
> interior of the Maglite as well, the acids eating away the Maglite's 
> shell in a way I literally didn't think was possible. Defective battery? 
> Some other problem? We may never know.

What brand of battery?  I haven't seen a battery fail like this
in decades.  Was the light stored in a harsh environment?

> Whatever the cause, I'd hate to even _contemplate_ the idea of that 
> possibly happening right next to a DEC backplane.