Help with battery installation

[Meanie]

My wife has an electric yarn spinner which operates from 120v outlet and
converts to a 12v 1.2 amp(max)DC power. Per the manufacturer, amps are
typically running at .5.

I want to provide a power source without the required need for a power
cord. Therefore, the obvious solution is battery power. The confusion
lies with the amps. I know all AAA, AA, C and D size battery outputs are
1.5 v (1.2 running) and each one puts out different amps. As I
understand it, amp output for AAA is roughly 1, AA is 2, C is 4 and D is
8. Therefore, I assume the AA, C and D are not needed due to the higher
amps since I will need at least 8 batteries to achieve 12 volts, unless
I go with a 9 volt plus two AAAs, which seems more logical since a 9v
puts out .5 amps. Anyway, this is the confusing part as what I need and
whether to connect in serial or parallel.

Can anyone provide some enlightenment for my lack of battery knowledge?

Thank you

 

[Tim Wescott]

On Sun, 23 Jun 2013 12:14:30 -0400, Meanie wrote:

My wife has an electric yarn spinner which operates from 120v outlet and
converts to a 12v 1.2 amp(max)DC power. Per the manufacturer, amps are
typically running at .5.

I want to provide a power source without the required need for a power
cord. Therefore, the obvious solution is battery power. The confusion
lies with the amps. I know all AAA, AA, C and D size battery outputs are
1.5 v (1.2 running) and each one puts out different amps. As I
understand it, amp output for AAA is roughly 1, AA is 2, C is 4 and D is
8. Therefore, I assume the AA, C and D are not needed due to the higher
amps since I will need at least 8 batteries to achieve 12 volts, unless
I go with a 9 volt plus two AAAs, which seems more logical since a 9v
puts out .5 amps. Anyway, this is the confusing part as what I need and
whether to connect in serial or parallel.

Can anyone provide some enlightenment for my lack of battery knowledge?

The numbers that you are listing is the current that the cells are
capable of putting out, not what they put out all the time, nor how long
they can put out that current.

Those also appear to be the absolute peak numbers for alkaline cells.

What you should be most interested in is the battery capacity. This is
generally listed in amp-hours or milli-amp hours. For instance, a two
amp-hour battery would be able to put out 0.5 amps for about four hours.

At a guess, a typical AAA dry cell will have a capacity of 250mAh; a
collection of them would be able to run your spinner, poorly, for about
half an hour. 9V batteries are worse.

If you want to power this from dry cells then you want eight to ten in
series (if the thing is a simple motor then you can go over voltage a bit
and not harm it). I'd use D cells.

If you want to power this from NiCd or NiMH cells then you want ten in
series. The last time I looked (which was years ago) the D cells were
just C cells inside a big tube, so you may as well use C cells.

But the best thing to do would probably be to find a cordless tool that
advertises itself as being 12 to 14 volts. Some of the contractor tools
are marketed as lines that all use a common battery and charger, but have
different tools that use the battery. I'd find the cheapest one
(probably a flashlight), rip the guts out and use it as a battery
adapter. Then I'd buy a few batteries and a charger, and I'd go to town.

She'll be cordless, she won't be constantly buying batteries, and
recharging won't be a pain.

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com

 

[Jasen Betts]

On 2013-06-23, Meanie <meanie.brat@gmail.com> wrote:

My wife has an electric yarn spinner which operates from 120v outlet and
converts to a 12v 1.2 amp(max)DC power. Per the manufacturer, amps are
typically running at .5.

I want to provide a power source without the required need for a power
cord. Therefore, the obvious solution is battery power. The confusion
lies with the amps. I know all AAA, AA, C and D size battery outputs are
1.5 v (1.2 running) and each one puts out different amps. As I
understand it, amp output for AAA is roughly 1, AA is 2, C is 4 and D is
8. Therefore, I assume the AA, C and D are not needed due to the higher
amps since I will need at least 8 batteries to achieve 12 volts, unless
I go with a 9 volt plus two AAAs, which seems more logical since a 9v
puts out .5 amps. Anyway, this is the confusing part as what I need and
whether to connect in serial or parallel.

it depends how poerable you want it to be and, how much you want to
spend on batteries, and how often you want to change them.

I'd reccomend AA as a starting point and they last much longer than
AAA but cost about the same price.

On the other hand a 12V rechargable tool battery pack might be a
better option, especially if you can borrow one to try out.

--
⚂⚃ 100% natural

--- news://freenews.netfront.net/ - complaints: news@netfront.net ---

 

[Bob Masta]

On Sun, 23 Jun 2013 12:14:30 -0400, Meanie
<meanie.brat@gmail.com> wrote:

My wife has an electric yarn spinner which operates from 120v outlet and
converts to a 12v 1.2 amp(max)DC power. Per the manufacturer, amps are
typically running at .5.

I want to provide a power source without the required need for a power
cord. Therefore, the obvious solution is battery power. The confusion
lies with the amps. I know all AAA, AA, C and D size battery outputs are
1.5 v (1.2 running) and each one puts out different amps. As I
understand it, amp output for AAA is roughly 1, AA is 2, C is 4 and D is
8. Therefore, I assume the AA, C and D are not needed due to the higher
amps since I will need at least 8 batteries to achieve 12 volts, unless
I go with a 9 volt plus two AAAs, which seems more logical since a 9v
puts out .5 amps. Anyway, this is the confusing part as what I need and
whether to connect in serial or parallel.

Can anyone provide some enlightenment for my lack of battery knowledge?

Thank you

A big issue here is how long the device needs to run between
battery charges (or changes). Batteries are rated in
amp-hours. You note that the device normally draws 0.5 A,
so you can find the *approximate* running time for each
battery type by looking up its A-H rating (sometimes
printed on the battery itself, especially for
rechargeables). If it's a 1.5V cell, you'll of course need
8 in series, as you note, but the same A-H rating applies.
Just divide the A-H rating by 0.5 to get hours.

If it needs long running time but doesn't need to be
particularly lightweight, you might consider a 12V sealed
lead-acid battery and charger.

Best regards,


Bob Masta

DAQARTA v7.21
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Scope, Spectrum, Spectrogram, Sound Level Meter
Frequency Counter, Pitch Track, Pitch-to-MIDI
FREE Signal Generator, DaqMusic generator
Science with your sound card!

 

On Sun, 23 Jun 2013 11:32:02 -0500, Tim Wescott
<tim@seemywebsite.please> wrote:

On Sun, 23 Jun 2013 12:14:30 -0400, Meanie wrote:

My wife has an electric yarn spinner which operates from 120v outlet and
converts to a 12v 1.2 amp(max)DC power. Per the manufacturer, amps are
typically running at .5.

I want to provide a power source without the required need for a power
cord. Therefore, the obvious solution is battery power. The confusion
lies with the amps. I know all AAA, AA, C and D size battery outputs are
1.5 v (1.2 running) and each one puts out different amps. As I
understand it, amp output for AAA is roughly 1, AA is 2, C is 4 and D is
8. Therefore, I assume the AA, C and D are not needed due to the higher
amps since I will need at least 8 batteries to achieve 12 volts, unless
I go with a 9 volt plus two AAAs, which seems more logical since a 9v
puts out .5 amps. Anyway, this is the confusing part as what I need and
whether to connect in serial or parallel.

Can anyone provide some enlightenment for my lack of battery knowledge?

The numbers that you are listing is the current that the cells are
capable of putting out, not what they put out all the time, nor how long
they can put out that current.

Those also appear to be the absolute peak numbers for alkaline cells.

What you should be most interested in is the battery capacity. This is
generally listed in amp-hours or milli-amp hours. For instance, a two
amp-hour battery would be able to put out 0.5 amps for about four hours.

At a guess, a typical AAA dry cell will have a capacity of 250mAh; a
collection of them would be able to run your spinner, poorly, for about
half an hour. 9V batteries are worse.

If you want to power this from dry cells then you want eight to ten in
series (if the thing is a simple motor then you can go over voltage a bit
and not harm it). I'd use D cells.

If you want to power this from NiCd or NiMH cells then you want ten in
series. The last time I looked (which was years ago) the D cells were
just C cells inside a big tube, so you may as well use C cells.

But the best thing to do would probably be to find a cordless tool that
advertises itself as being 12 to 14 volts. Some of the contractor tools
are marketed as lines that all use a common battery and charger, but have
different tools that use the battery. I'd find the cheapest one
(probably a flashlight), rip the guts out and use it as a battery
adapter. Then I'd buy a few batteries and a charger, and I'd go to town.

She'll be cordless, she won't be constantly buying batteries, and
recharging won't be a pain.
Using a power tool sounds like a good idea. And if the spinner doesn't

have variable speed, and if your wife would like it, you might be able
to use an electric drill's variable speed circuitry by just
disconnecting the wires from the motor and connecting them to the
spinner. Be sure the polarity is correct when connecting batteries.
Eric

 

[Meanie]

Thank you all for the suggestions. I like the idea of a tool battery.
I'm in the hunt for a 2nd charger for one of my 12v power tools. I plan
to gut the charger and leave the prongs for battery connection. Wire
from the prongs connecting to the required size adapter plug for the
spinner. Therefore, the battery will have a holder and I can recharge it
with my other charger. Sounds good in my head, I hope it works out that way.

 

[Meanie]

On 6/24/2013 1:13 PM, etpm@whidbey.com wrote:

Using a power tool sounds like a good idea. And if the spinner doesn't
have variable speed, and if your wife would like it, you might be able
to use an electric drill's variable speed circuitry by just
disconnecting the wires from the motor and connecting them to the
spinner. Be sure the polarity is correct when connecting batteries.
Eric

It's already variable speed. I just need the portable power source.

 

[Michael A. Terrell]

Meanie wrote:

On 6/24/2013 1:13 PM, etpm@whidbey.com wrote:

Using a power tool sounds like a good idea. And if the spinner doesn't
have variable speed, and if your wife would like it, you might be able
to use an electric drill's variable speed circuitry by just
disconnecting the wires from the motor and connecting them to the
spinner. Be sure the polarity is correct when connecting batteries.
Eric

It's already variable speed. I just need the portable power source.

These go on sale for $40 fairly often. Not only will it power her
toy, it can jump start a car, or provide emergency lighting.

<http://www.harborfreight.com/12-volt-jump-start-and-power-supply-38391.html>

 

On Mon, 24 Jun 2013 17:44:51 -0400, Meanie <meanie.brat@gmail.com>
wrote:

On 6/24/2013 1:13 PM, etpm@whidbey.com wrote:

Using a power tool sounds like a good idea. And if the spinner doesn't
have variable speed, and if your wife would like it, you might be able
to use an electric drill's variable speed circuitry by just
disconnecting the wires from the motor and connecting them to the
spinner. Be sure the polarity is correct when connecting batteries.
Eric

It's already variable speed. I just need the portable power source.
Well there Ya go. You're all set.

Eric