AA-sized conductor (fake battery) wanted

[Eldor]

Hello all NG

I am looking for a fake AA battery, i.e. a conductor of the same size,
so that I can put it in an AA battery holder and have a lower voltage
(N-1 x 1.5V) . Actually I want multiple of them so that I can make a
"configurable voltage" battery.

I have looked around but I can't find it. Does anybody know any?

Alternatively I could look for a battery which can be charged at various
voltage levels, but it needs to hold a significant charge at any voltage
level. I don't think it exists.

Thanks for any help

 

[baron]

Eldor Inscribed thus:

Hello all NG

I am looking for a fake AA battery, i.e. a conductor of the same size,
so that I can put it in an AA battery holder and have a lower voltage
(N-1 x 1.5V) . Actually I want multiple of them so that I can make a
"configurable voltage" battery.

I have looked around but I can't find it. Does anybody know any?

Alternatively I could look for a battery which can be charged at
various voltage levels, but it needs to hold a significant charge at
any voltage level. I don't think it exists.

Thanks for any help

Whats wrong with a piece of rolled up cardboard ?

 

[D Yuniskis]

Hello all NG

I am looking for a fake AA battery, i.e. a conductor of the same size,
so that I can put it in an AA battery holder and have a lower voltage
(N-1 x 1.5V) . Actually I want multiple of them so that I can make a
"configurable voltage" battery.

I have looked around but I can't find it. Does anybody know any?

Many handheld radios are equipped with exactly this sort of
thing (i.e., I have a couple of such radios, each with a pair
of die-cast "fake batteries" -- nothing more than 0 ohm spacers).
This allows different battery technologies to be used in the
radio.

You could fabricate one using a length of copper pipe with
suitable "end caps" soldered on.

 

[D Yuniskis]

Eldor Inscribed thus:


Whats wrong with a piece of rolled up cardboard ?

Cardboard isn't a very good conductor at low voltages :>

 

[JW]

Hello all NG

I am looking for a fake AA battery, i.e. a conductor of the same size,
so that I can put it in an AA battery holder and have a lower voltage
(N-1 x 1.5V) . Actually I want multiple of them so that I can make a
"configurable voltage" battery.

I have looked around but I can't find it. Does anybody know any?

Alternatively I could look for a battery which can be charged at various
voltage levels, but it needs to hold a significant charge at any voltage
level. I don't think it exists.

Thanks for any help

How about this:
http://www.amazon.com/Quantum-ES2-Dummy-Battery-Energy/dp/B0000C5RR8
http://www.bhphotovideo.com/c/product/43271-REG/Quantum_Instruments_ES2_ES2_Energy_Saver.html

 

[William Sommerwerck]

How about this:

http://www.amazon.com/Quantum-ES2-Dummy-Battery-Energy/dp/B0000C5RR8

http://www.bhphotovideo.com/c/product/43271-REG/Quantum_Instruments_ES2_ES2_Energy_Saver.html

These would obviously do what the OP wanted -- though the price is not
right. One might solder lengths of copper tubing (which you can get at hobby
stores) to metal disks -- but I don't know how sturdy they'd be.

WARNING! The following is off-topic -- but worth thinking about.

These dummy cells are supposed to be energy savers, because they let you use
only three AA alkaline cells in a four-cell flash. This works, because most
flashes operate correctly with nicad or NiMH cells, which are nominally
1.25V (rather than the 1.5V of alkalines).

However, this is a great way to waste money -- and not just the cost of the
dummy cell. With only three cells in the flash, you won't be able to
discharge them to as low a voltage as you would with four. That means you'll
have to discard them sooner, and you'll get less total energy out of them.

 

[PeterD]

Cardboard isn't a very good conductor at low voltages :>

It is if you start with a piece of 18 AWG wire in the center!

 

[William Sommerwerck]

WARNING! The following is off-topic -- but worth thinking about.

These dummy cells are supposed to be energy savers, because they
let you use only three AA alkaline cells in a four-cell flash. This works,
because most flashes operate correctly with nicad or NiMH cells, which
are nominally 1.25V (rather than the 1.5V of alkalines).

However, this is a great way to waste money -- and not just the cost
of the dummy cell. With only three cells in the flash, you won't be able
to discharge them to as low a voltage as you would with four. That means
you'll have to discard them sooner, and you'll get less total energy out of
them.

I just called Quantum, and found out that these actually aren't "energy
savers" at all. In fact, there might be circuitry in them (which is why
there are two models).

If you own a Canon flash (I assume Nikons are the same) and have read the
wretched manual, you know that, when using an external power pack, you must
leave the AA cells in the flash, because they continue to power the control
circuitry. It appears that going from 4 cells to 3 reduces the drain on the
cells, and presumably extends their life.

 

[Smitty Two]

Hello all NG

I am looking for a fake AA battery, i.e. a conductor of the same size,
so that I can put it in an AA battery holder and have a lower voltage
(N-1 x 1.5V) . Actually I want multiple of them so that I can make a
"configurable voltage" battery.

I have looked around but I can't find it. Does anybody know any?

Alternatively I could look for a battery which can be charged at various
voltage levels, but it needs to hold a significant charge at any voltage
level. I don't think it exists.

Thanks for any help

As an alternative, Radio Shack and other suppliers have AA and AAA
battery holders, in say 3-cell and 4-cell configurations, with movable
contacts. This permits you to use different numbers of cells, or choose
between parallel and series configurations, just by slipping the stamped
metal contacts out of one groove and into another.

I designed a little gadget for a customer using a 4-cell AAA unit. I set
it up for 3-cell operation, and use the 4th slot for a small circuit
board. The boxes come with a cover and an integral ON-OFF switch. Pretty
handy. They're about $2 each at Radio Shack, and I pay about a $1 each
in 100 pc. qty. from Mouser, etc.

 

[Baron]

D Yuniskis Inscribed thus:

Cardboard isn't a very good conductor at low voltages :>

Sorry ! My brain fart :-(
I meant to write "Whats wrong with a piece of alloy foil wrapped over
rolled up cardboard ?"

 

[Meat Plow]

Hello all NG

I am looking for a fake AA battery, i.e. a conductor of the same size,
so that I can put it in an AA battery holder and have a lower voltage
(N-1 x 1.5V) . Actually I want multiple of them so that I can make a
"configurable voltage" battery.

I have looked around but I can't find it. Does anybody know any?

Alternatively I could look for a battery which can be charged at various
voltage levels, but it needs to hold a significant charge at any voltage
level. I don't think it exists.

Thanks for any help

Radio Shack used to sell them.

 

[D Yuniskis]

D Yuniskis Inscribed thus:


Sorry ! My brain fart :-(
I meant to write "Whats wrong with a piece of alloy foil wrapped over
rolled up cardboard ?"

Wrapping the foil might be tricky -- especially if it
*is* "foil" -- since you want a durable and reliable
contact surface yet can't really tolerate lumps, bumps,
etc. "Shrink-wrap-aluminum"! Now *that* would be
an idea! :> (not "shrink-WRAPPED-aluminum")

The ideal would be to turn a length of copper dowel to
the correct profile and then encase in shrink wrap.
But, I suspect the OP doesn't have access to a lathe
(though many people *have* lathes so "asking around"
could be an option -- note that the profile is probably
published as a standard someplace so it's just a matter
of getting someone to give you 3 minutes of time on a
lathe).

My "dummy cells" look like "I" beams in cross section.
I.e., imagine the top and bottom 1/10th of an inch of a
cell joined by a thick *sheet* of metal. Very obviously
castings and saved on material by not making them
solid cylinders.

 

[Spehro Pefhany]

Hello all NG

I am looking for a fake AA battery, i.e. a conductor of the same size,
so that I can put it in an AA battery holder and have a lower voltage
(N-1 x 1.5V) . Actually I want multiple of them so that I can make a
"configurable voltage" battery.

I have looked around but I can't find it. Does anybody know any?

Alternatively I could look for a battery which can be charged at various
voltage levels, but it needs to hold a significant charge at any voltage
level. I don't think it exists.

Thanks for any help

You could probably adapt a AAA->AA adapter pretty easily. Cost < $1
each from China a couple at a time.


Best regards,
Spehro Pefhany

 

[Larry]

Hello all NG

I am looking for a fake AA battery, i.e. a conductor of the same size, so
that I can put it in an AA battery holder and have a lower voltage (N-1 x
1.5V) . Actually I want multiple of them so that I can make a
"configurable voltage" battery.

I have looked around but I can't find it. Does anybody know any?

Alternatively I could look for a battery which can be charged at various
voltage levels, but it needs to hold a significant charge at any voltage
level. I don't think it exists.

Thanks for any help

Check at Home Depot for aluminum rod.
http://www.homedepot.com/webapp/wcs...m+rod&langId=-1&storeId=10051&catalogId=10053

Larry

 

[Eldor]

Thank you, thank you everybody, it's enough ))
Now I have a few things to try!!
:-D

 

[baron]

D Yuniskis Inscribed thus:

Wrapping the foil might be tricky -- especially if it
*is* "foil" -- since you want a durable and reliable
contact surface yet can't really tolerate lumps, bumps,
etc. "Shrink-wrap-aluminum"! Now *that* would be
an idea! :> (not "shrink-WRAPPED-aluminum")

I've actually used rolled up cardboard and wrapped aluminium cooking
foil round it, folding the ends over to make contact surfaces. It
works quite well. I imagine that its current carrying capacity would
be quite low.

The ideal would be to turn a length of copper dowel to
the correct profile and then encase in shrink wrap.
But, I suspect the OP doesn't have access to a lathe
(though many people *have* lathes so "asking around"
could be an option -- note that the profile is probably
published as a standard someplace so it's just a matter
of getting someone to give you 3 minutes of time on a
lathe).

Actually a hacksaw and a short length of 0.5" or 13.0mm bar/rod cut to
2" or 51mm long would do !

My "dummy cells" look like "I" beams in cross section.
I.e., imagine the top and bottom 1/10th of an inch of a
cell joined by a thick *sheet* of metal. Very obviously
castings and saved on material by not making them
solid cylinders.

I've seen something similar made from mazak alloy.

 

[D Yuniskis]

D Yuniskis Inscribed thus:


I've actually used rolled up cardboard and wrapped aluminium cooking
foil round it, folding the ends over to make contact surfaces. It
works quite well. I imagine that its current carrying capacity would
be quite low.


Actually a hacksaw and a short length of 0.5" or 13.0mm bar/rod cut to
2" or 51mm long would do !

My comment was intended more as "tongue-in-cheek" (I have a
friend that I *never* ask for things like this as he *would*
turn something on a lathe for me and I often end up embarassed
at the "excessive quality" of his solution! :> )

Some batteries (against which the "dummy" may mate) require
the little "nub" on the + end to ensure contact. Likewise,
some battery holders "guard" the + terminal with a bit of
raised plastic to protect against a battery installed backwards.
(i.e., a "flat surface" -- like the - terminal -- won't connect)

 

[Baron]

D Yuniskis Inscribed thus:

My comment was intended more as "tongue-in-cheek" (I have a
friend that I *never* ask for things like this as he *would*
turn something on a lathe for me and I often end up embarassed
at the "excessive quality" of his solution! :> )

Us mechanical engineer types take great pride in our hobbies !

Some batteries (against which the "dummy" may mate) require
the little "nub" on the + end to ensure contact. Likewise,
some battery holders "guard" the + terminal with a bit of
raised plastic to protect against a battery installed backwards.
(i.e., a "flat surface" -- like the - terminal -- won't connect)

Ah ! In that case you would need to turn it to produce the pip on one
end.

 

[D Yuniskis]

Us mechanical engineer types take great pride in our hobbies !

Well, *he's* the mechanical type: lathe, end mill, surface grinder,
shadow graph, coil winder, etc.

Of course, another friend has a sinker EDM and a couple of wire EDM
machines... a bit too expensive to qualify as "toys" :-/

Ah ! In that case you would need to turn it to produce the pip on one
end.

Yes, that was why I suggested the lathe instead of just cutting drill
rod, etc.

Though, with copper, I think you could *almost* use a file as "cutting
tool" and a large electric (hand) drill to spin the work. Wouldn't have
much control over the dimension of the pip but I suspect you could
fashion a functional one in a few minutes. Heck, even putting a
slight taper on the one end would work!

 

[Baron]

D Yuniskis Inscribed thus:

Well, *he's* the mechanical type: lathe, end mill, surface grinder,
shadow graph, coil winder, etc.

Of course, another friend has a sinker EDM and a couple of wire EDM
machines... a bit too expensive to qualify as "toys" :-/

Ooo ! I feel the green eyed monster coming on.

Yes, that was why I suggested the lathe instead of just cutting drill
rod, etc.

I wasn't aware of that limitation. Though my son just pointed out the
battery holder in the Wii was shaped so you couldn't put the battery in
backwards.

Though, with copper, I think you could *almost* use a file as "cutting
tool" and a large electric (hand) drill to spin the work. Wouldn't
have much control over the dimension of the pip but I suspect you
could fashion a functional one in a few minutes. Heck, even putting a
slight taper on the one end would work!

Very true ! A trick I've used to clean up the end of damaged bolts.