Date   : Tue, 08 Nov 2005 16:53:35 -0000
From   : "David Hunt" <dm.hunt@...>
Subject: Master battery packs

Hi,

My Master has lost its memory today. I opened it up and took the battery
out.

The battery is a pair of Sanyo Laser Lithium CR12600SE 3V cells wired in
series, dated 86-03.

These cells haven=92t been changed since it was new =96 they haven=92t
leaked or
corroded either. Supposedly, they explode...

Question is what do I replace them with, these old lithium cells
aren=92t easy
to get hold of. They are really Manganese Dioxide Lithium. Not a Maplin
purchase, however, this site lists them

<http://www.mdsbattery.co.uk/shop/productprofile.asp?ProductGroupID=733
&Bran
d=&DepartmentName=&DepartmentID=146> £9.40 a pop!

I have seen posts from a long while back about use alkaline cells and a
diode and resistor. The output voltage from such a configuration is
likely
to be less than 3V once the 0.7V drop across the diode (assuming
silicon) is
taken into account. 

Considering the original battery was 6V, plus my refusal to change
batteries
every year, why can't I replace the battery with a 6V lithium camera
battery? They've got five times the capacity and more or less the same
size
as what I've removed.

Looking on the web I saw a page referring to rechargeable Lithium cells
-
the cells I removed specifically say "do not recharge" - so I don't
think
that the site is correct. i.e.
<http://lionels.orpheusweb.co.uk/CompNyb/TechStuff/8-Bit/Master128/128Bat
Con
fig.html>

Has anyone had experience of the batteries actually exploding or was
this
related to another issue that Acorn kept quiet about?

Kind regards

Dave ;)