🚀 go-pugleaf

In sci.electronics.design Dale <ewgeneral@yahoo.com> wrote:
> I need to measure the discharge from a 3V Lithium 'coin' cell,
> supplying current to some static ram and low power support circuitry.
> 
> This battery is supposed to have a 10 yr backup capability, which i
> need to confirm, but I imagine the I to be in the very low uA to nA
> range
> 
> Has anyone got any ideas on how to measure this reasonably accurately?

Take an oscilloscope, connect the (floating) device to it with the scope
probe in series with the battery.
Voila, now the 2mv scale gives you 2na/division.
Add shunt resistors as appropriate.

A DMM can also work, on the voltage ranges, or even the current ranges for
ua, but unless very expensive won't catch spikes.

A basic verification tool is to try it again backwards, just to make
sure gremlins arn't creeping in.

-- 
http://inquisitor.i.am/    |  mailto:inquisitor@i.am |             Ian Stirling.
---------------------------+-------------------------+--------------------------
"An enemy will usually have three courses open to him.  Of these he will
select the fourth."                                    -- Helmuth von Moltke