Thanks Dal,

Actually I have done what you have suggested.  I came up with 35 years (with
2400 mAh x 0.70 (self discharge per year over 10 years)).  So, since the
battery will last for 10 years and considering the self discharge, the
calculations shows that the unit will run for 10 years.  But that's
theoretical.  I wanted to test it for real with a very small battery.  But
it seems that would not be possible.

-----Original Message-----
From: pic microcontroller discussion list [mailto:PICLIST@MITVMA.MIT.EDU] On
Behalf Of Dal Wheeler
Sent: Saturday, November 08, 2003 3:19 AM
To: PICLIST@MITVMA.MIT.EDU
Subject: Re: [EE:] Testing prototype with a battery

Sorry Vmer, I was joking a little bit there.  Basically, how long do the
batteries really have to last?  I just saw the Tadiran website you listed in
another email.  These look like a different breed of battery from what I'm
used to seeing.  I'm not sure that increasing the load will give you much
information as far as projecting what you can expect from a real
installation over the full length of the real time discharge.   Why not just
take the curve  from the battery datasheet for your current consumption and
derate it a few percent for a safety factor. Real world longevity will vary
a bit depending on where the device is installed anyway.  I guess the only
real way is to set up a bunch of these and see how long they actually last.

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