On 04/26/14 00:06, Michael Hennebry wrote:
> On Fri, 25 Apr 2014, g wrote:
>
>> something i will suggest, being that you pulled cell from
>> a dead board, consider getting another cell.
>>
>> then, wrap cell and package it is in with 'saran wrap', squeeze
>> out as much a possible, then wrap with aluminum foil. place in
>> freezer and it will be waiting for you when you need it. do
>> allow 12 - 16 hours for warm up before using.
>
> Makes sense to me.
> I'll do that the next time I do a mail order.
oops. should have read;
"squeeze out as much _air_ as possible when folding".
be careful of 'mail order' batteries. not all supply cells and
batteries with current expiration dates. even tho such places
sell a lot of cells and batteries, it does not mean they are
selling 'new' stock.
most all, with exception of equipment suppliers, will have a
code of sum type, letters and/or numbers, or actual date of
when 'shelf life' expires.
also, if you have a 'batteries plus' store in your area, you
may well be better off buying from them, as the cr2032 is a
commonly used cell and would have a high turn over. and you
would save on shipping costs.
>> i have kept batteries and cells in freezer for over 10 years and
>> they still give over 1 year 'shelf life' service. i do not
>> recommend doing such with "silicone" batteries', aka, "gel cell"
>> batteries.
>>
>> also, when you change a cmos cell, you may do so with power
>> supply turned on to preserve cmos settings.
>
> That I did not know.
> 'Tis contrary to a lot of other advice,
> but it makes sense.
in freezing, chemical reaction within cells is reduced,
inverse of what high temps due.
changing a cell with power on is safe because there is usually
a diode, some include a low ohm resistor, in series with cell
to block voltage supplied by ps on. with such, there is no load
on cell and no possible 'current shock' from arching when cell
is removed.
> Other things that I might want to preserve include two power supplies,
> an IDE-only CD reader, an IDE-only DVR writer and an AGP video card.
> I do not have a lot of convenient storage space on my main floor.
> Ideally, none of the five will be used for a while.
> Suggestions regarding storage?
should/may not be a problem, but...
as with all electronics that have polarized electrolytic
capacitors, these capacitors need 'forming' when they have
been with out power for extended periods. the 'dry out' period
various drastically and is more critical with high farad/high
voltage types. less critical in current day digital circuits.
tho this may not hold totally true with power supplies that
have powered down for very long periods.
forming is usually done by bring voltage up slowly and at a
time period on tens of minutes before reaching full state.
if you are storing for periods of months, verses years, there
should not be anything to worry about.
if you actually wanted to stay on a 'safe side' and have a variac,
aka, variable transformer, you could hook one up, start at zero
and step increase to 100% over a 10 to 20 minute period. then
remove power for a short period and repeat process.
not having a variac, a 25 to 50 watt incandescent lamp in series
can work.
adverse effect of not forming is that charge builds too quickly
and capacitor insulation ruptures and a short forms.
if you are real curious about forming and want to see just what
is going on, connect a current meter in series with an 'out of
circuit' capacitor (of large farad) and a volt meter across
capacitor. follow above voltage stepping. each time you repeat
process, you will see a faster current swing and larger 'top
voltage' until you reach a point where 'top voltage' is reached
quickly each time power is applied.
> I also have four 1-GB DDR2 memory cards.
> My two exant computers have two 2-GB DDR2
> memory cards each and room for two more cards,
> As the information does not seem to be on the cards,
> I will probably have to do a search to discovery
> whether the old cards can keep up with the new.
switching frequency of memory chips is what is important.
this can be found by searching the chip part numbers.
> Supposing they can, I am debating between prompt
> install and waiting until I need more memory.
> If I put them in an anti-static bag first,
> would the freezer trick work with the memory cards?
no.
this has gotten way 'off topic'. if you have an more interest
about forming capacitors, contact me "off list".
--
peace out.
in a world with out fences, who needs gates.
tc.hago.
g
.
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