On Tue, 02 Sep 2014 17:18:31 +0100, Johny B Good
wrote:

On Tue, 02 Sep 2014 03:59:52 +0100, Grimly Curmudgeon
wrote:

On Fri, 29 Aug 2014 15:53:08 +0100, Johny B Good
wrote:

I suppose it depends on how much value you place on the benefit of
having a functioning Mempac battery fitted into the controller. In my
case, it's not so critical for every day operation with the mains
supply proving, thus far, to be as reliable as it has been over the
past 30 years or so where I live.

My main hope in posting my query was that someone else in this group
may have already dealt with this issue in a remarkably economic way
and would jump at the excuse to disseminate their hard won knowledge.
:-) If you don't ask, you'll never find out so it's worth a punt
before wandering off into the wilderness of commercial reality.

Done similar; when I couldn't find the exact battery (or at an
exhorbitant price) I made an external pack and encased it in a similar
surface-mount unit to the controller. Looked fine, and not out of
place.

That's it for me too. I wasn't desperate so I was prepared to just
keep my eye out for either an old battery pack's worth of canditate
cells with 'goodish' ones I could canabilse or something in better
nick that would fit the bill.

As it happened, I discovered the solution in CPC's minimum (pre-VAT)
5 quid order facility with free postage on card transactions so
problem solved. :-)

And, the parcel arrived in the midday post yesterday. It took me
less than ten minutes to remove the battery tags and dress the spot
weld pips with a file to add another three quid's worth of value to
it. :-)

I've installed it into the controller and verified it allowed it to
maintain the time when switched off at the mains. I'm leaving it
switched for 24 hours or so (I haven't turned the boiler back on -
still waiting for the winter season) to recharge the battery which was
showing 1.25333v/cell before I started adding value to it.

I came across the invoice for the Bosch 40W E14 oven lamp this
evening and saw that it had cost me nearly 6 quid! (VAT inclusive
price). Making up the order value with a 40W E14 oven lamp cost me
just one fifth the price of the Bosch sourced one. The 60p audio lead
I had to add to get over the 5 quid minimum order hump will _probably_
come in handy sometime in the next decade or so I'm sure.

All in all, a very satisfactory resolution to my quest (and possibly
a useful hint to others in need of a cheap replacement controller
backup battery).

Now all I have to do is gird up my loins to tackle that awkwardly
placed Honeywell diverter valve. :-(
--
J B Good