[sdiy] [seq] 615 Multi-Trak Memory Battery Probs.

[Roy J. Tellason]

On Saturday 14 August 2004 10:44 pm, Dave Garfield wrote:
> Hi there, list!
>
> I have a Sequential 615 Multi-Trak with Rev A boards, that keeps
> discharging memory backup batteries.  Now, I installed a holder and
> CR2035 3V Lithium battery in place of the missing original battery, but
> the two batteries I've used so far don't last longer than about six
> weeks before going completly, totally DEAD!

Congrats on installing the holder,  as this seems to have been omitted from an 
awful lot of stuff as it came from the factory.  I used to offer that when I 
was doing service.  Do you mean CR2032?  I've seen that one in bunches of 
stuff,  never heard of a CR2035.

> Has this happened to any of you out there?  Is there a better,
> longer-lasting battery that would be better than the CR2035?

I don't know what was in that unit from the factory,  but this doesn't sound 
like it's a bad choice.

Here's a tip for those particular battery numbers:  This goes for the "BR" 
ones too -- the first two digits are the diameter in mm,  and the second two 
digits after that are the thickness in tenths of a mm.  So this is 20mm in 
diameter and 32 (35?) mm thick.

When I did a retail battery store for a couple of years,  the ones we carried 
in that series were 2016, 2025, and 2032.  There are also some slightly 
larger ones,  25xx,  I think.

> Maybe I should suspect a short somewhere, that would slowly drain the memory
> battery?  Are Six-Traks/Multi-Traks known for this, or is mine quirky?

It may be that there's something draining it all right.   Seems to me it would 
last longer than that,  though I never did do much work on that particular 
brand when I was working on stuff.

What I'd suggest if you have a meter handy is to set it up to measure current 
and to connect it in line with the battery -- this should be easier with a 
holder there than it might be otherwise.  I haven't done this with much 
stuff,  but some time back I got curious about how this would go with some 
2kx8 and 8kx8 CMOS ram chips I had around here,  and the drain was *very* 
small,  around one microamp or so.  Ten times that is still pretty 
reasonable.   Several milliamps,  or even higher is probably not.