Seek conducting "shim" to measure battery current

[Zak]

Can I buy something in the UK like a conducting "shim" to insert
between batteries and measure current?

Below are some details of what I mean.


===============================================

I want to measure the current provided by the battery when
something like a radio or walkman is used. The battery might be
anything from AAA to D and could be any type(alkaline, zinc-
carbon, rechargeable, etc).

----

I once made a "shim" out of a small thin piece of plastic which
was sandwiched by thin metal conductors on either side. A wire
was attached to each conductor and the two wires went a
multimeter.

The idea is to insert this "shim" between the cells. Then run the
appliance and measure the current you settings like volume, fast
forwards, band select, etc.

 

[Yukio YANO]

Can I buy something in the UK like a conducting "shim" to insert
between batteries and measure current?


----

Can I buy something here in the UK like this "shim" to insert
between batteries and measure current? My "shim" was always bit
too thick and wan't durable.

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

 

[Jim Yanik]

Can I buy something in the UK like a conducting "shim" to insert
between batteries and measure current?

Below are some details of what I mean.


===============================================

I want to measure the current provided by the battery when
something like a radio or walkman is used. The battery might be
anything from AAA to D and could be any type(alkaline, zinc-
carbon, rechargeable, etc).

----

I once made a "shim" out of a small thin piece of plastic which
was sandwiched by thin metal conductors on either side. A wire
was attached to each conductor and the two wires went a
multimeter.

The idea is to insert this "shim" between the cells. Then run the
appliance and measure the current you settings like volume, fast
forwards, band select, etc.

----

Can I buy something here in the UK like this "shim" to insert
between batteries and measure current? My "shim" was always bit
too thick and wan't durable.

Use a piece of .031 doublesided copperclad PCB stock;solder a wire to each
side for connecting to a DMM.
Sand the edges to make sure you don't have any shorts.

 

[Dave Platt]

Can I buy something in the UK like a conducting "shim" to insert
between batteries and measure current?

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.

 

[Roy L. Fuchs]

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.

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.

 

[Ken Weitzel]

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

 

[Dave Platt]

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.

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.[/QUOTE]

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.

 

[Guest]

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.

Indeed. I use a 3v lithium battery in my PZMs; I've never had to replace
them.

Norm Strong

 

[Mike]

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.

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.

 

[Jim Poore]

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.

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

 

[Spehro Pefhany]

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