Seek conducting "shim" to measure battery current

First choice would be a scrap of double-sided Printed-Circuit Board !

2nd choice would a Sandwich of Copper-Foil Tape and sheet of plastic. two sources come to mind, 1. Adhesive coated Copper Tape used to Alarm Windows. 2. Copper Tape, from Hobby stores for "Stained Glass" projects.

I used the Double sided PC board about 40 years ago while working for a Bio-medical Telemetry Equipment company.

Yukio YANO

I'd look around for a scrap piece of the thinnest double-sided PC-board copperclad that I could find. A few years ago I picked up a few sheets of a very flexible double-sided copperclad - maybe .5 mm thick - at a local surplus store. Quite useful stuff to have around.

On Wed, 22 Feb 2006 19:29:01 -0000, snipped-for-privacy@radagast.org (Dave Platt) Gave us:

Measuring a rechargeable battery is one thing, but if one is attempting to measure non rechargeable batteries this way, one will deplete the batteries with each and every measurement cycle.

Hi...

But only by the amount that the device it in uses; and only for the duration of the test...

Or is there something here I'm not seeing?

Ken

I don't see that at all, if the device is used in the way that I think the original poster had intended. The "conducting shim" has contacts on both sides. The two sides are connected together electrically through a current meter of some sort. To measure the current drawn from a battery, one would insert the shim in between two cells in a battery (breaking the normal connection between the cells' contacts with the shim) and then turn on the load for a few seconds. The normal flow of current to the load would go from one cell, along one side of the shim, out into the current meter, back into the other side of the shim, and out into the other cell of the battery.

There would be no additional losses except for the slight resistive loss in the shim and the current meter. If the load is switched off, no current will flow and no battery power/capacity will be depleted. The shim doesn't create a _new_ load for the battery - it just provides a convenient way to insert a current meter into the current path for measurement.

I think you're confusing "shim" with "shunt".

It's not a battery tester (like those infernal Duracell things that come free in the packet with batteries) that's designed to load the batteries ... and go a pretty colour, showing how much of your battery is left now that you've wasted some power showing off how full it is :)

It's just a handy way to break in to the circuit to measure current that is ALREADY flowing, without spring loaded batteries going "ping" everywhere or accidentally interrupting the current by slipping with a probe.

I'm sorry....how can this be? Anything inserted in series with the battery will only raise the load resistance causing less current to flow, not more.

Jim

Maybe. If there's a switching regulator, then inserting a voltage drop will cause more current to be drawn from the batteries.

Best regards, Spehro Pefhany