Hi.
Could anyone advise please

1 led drawing 10mA off a 12volt car battery,how long would
take to use up 1amp of the battery.

Thanks.
..Baz

--
Don't Thieve.
The government doesn't like competition.

"ForeverArsenal" wrote in message
et...
Hi.
Could anyone advise please

1 led drawing 10mA off a 12volt car battery,how long would
take to use up 1amp of the battery.

Thanks.
.Baz

Am I right in saying it would take 100hrs,could someone confirm please.

On Mon, 29 Dec 2008 20:38:07 -0000, "ForeverArsenal"
wrote in
:

"ForeverArsenal" wrote in message
net...
Hi.
Could anyone advise please

1 led drawing 10mA off a 12volt car battery,how long would
take to use up 1amp of the battery.

Am I right in saying it would take 100hrs,could someone confirm please.

Amp is current, not battery capacity. That's amp hours (current over
time).

Wikipedia:

The battery capacity that battery manufacturers print on a battery is
the product of 20 hours multiplied by the maximum constant current
that a new battery can supply for 20 hours at 68 F° (20 C°), down to
a predetermined terminal voltage per cell. A battery rated at 100 A·h
will deliver 5 A over a 20 hour period at room temperature.

Your LED is drawing 1/100 amp, so it would draw the same power in 100
hours as a 1 amp load would draw in one hour, or 1 amp hours of
capacity.

--
Very best wishes for the holiday season and for the coming new year,
John

On Mon, 29 Dec 2008 20:38:07 -0000, "ForeverArsenal"
wrote:


"ForeverArsenal" wrote in message
net...
Hi.
Could anyone advise please

1 led drawing 10mA off a 12volt car battery,how long would
take to use up 1amp of the battery.

Thanks.
.Baz

Am I right in saying it would take 100hrs,could someone confirm please.


I assume you mean "use 1 ampere-hour".

10 mA is 0.01 Amp (1/100 Amp), so it would take 100 hours for the 10
mA LED to consume 1 AH.


--
Peter Bennett, VE7CEI
peterbb4 (at) interchange.ubc.ca
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca

"Peter Bennett" wrote in message
news.com...
On Mon, 29 Dec 2008 20:38:07 -0000, "ForeverArsenal"
wrote:


"ForeverArsenal" wrote in message
snet...
Hi.
Could anyone advise please


I assume you mean "use 1 ampere-hour".

10 mA is 0.01 Amp (1/100 Amp), so it would take 100 hours for the 10
mA LED to consume 1 AH.
'''''''''''''''''''''''''''''''''''''''''''''''''' ''''''''''''''''''''''''''''''''''''''''
Many thanks Peter Bennett and John Navas for your replies
and infomation,appreciated.

Best wishes to you both for the new year.

Barry

ForeverArsenal wrote:
Hi.
Could anyone advise please

1 led drawing 10mA off a 12volt car battery,how long would
take to use up 1amp of the battery.

Thanks.
.Baz

100 hours.

Sjouke Burry" wrote in message
... ForeverArsenal wrote:
Hi.
Could anyone advise please

1 led drawing 10mA off a 12volt car battery,how long would
take to use up 1amp of the battery.

Thanks.
.Baz

100 hours.

Thanks.
Baz

--
Don't Thieve.
The government doesn't like competition.


"

On Mon, 29 Dec 2008 12:46:01 -0800, John Navas
wrote:

On Mon, 29 Dec 2008 20:38:07 -0000, "ForeverArsenal"
wrote in
:

"ForeverArsenal" wrote in message
snet...
Hi.
Could anyone advise please

1 led drawing 10mA off a 12volt car battery,how long would
take to use up 1amp of the battery.

Am I right in saying it would take 100hrs,could someone confirm please.

Amp is current, not battery capacity. That's amp hours (current over
time).

Wikipedia:

The battery capacity that battery manufacturers print on a battery is
the product of 20 hours multiplied by the maximum constant current
that a new battery can supply for 20 hours at 68 F° (20 C°), down to
a predetermined terminal voltage per cell. A battery rated at 100 A·h
will deliver 5 A over a 20 hour period at room temperature.

Your LED is drawing 1/100 amp, so it would draw the same power in 100
hours as a 1 amp load would draw in one hour, or 1 amp hours of
capacity.

Just shows that you cannot trust Wickipedia!
That should read ..

The battery capacity that battery manufacturers print on a battery is
the product of "The hour rating" in hours multiplied by the maximum
constant current that a new battery can supply for "The hour rating"
at 68 F° (20 C°), down to a predetermined terminal voltage per cell. A
battery rated at 100 A·h will deliver 100/(The hour rating) over "The
hour rating" period at room temperature.

"The hour rating" may be 20 it may be 5 depending upon the
manufacturer and the area of the world that the battery is sold in.

The Peukert exponent will mean that the 20 hour rating is NOT 4 times
the 5 hour rating.

The answer to the original question is therefore (because of Peukert).

Based on a 20 hour rated battery a drain of 10ma will reduce the
battery capacity by 1 Ampere Hour in a time that is a hell of a lot
greater than 100 hours.
Just for example based upon a 100Ah battery at a 20 hour rate with a
Peukert of 1.3, a drain of .050A will actually look like .010A.
Therefor a drain of .05A will pull 1Ah in 100 hours.

Richard

In article , Richard Edwards wrote:
On Mon, 29 Dec 2008 12:46:01 -0800, John Navas
wrote:

On Mon, 29 Dec 2008 20:38:07 -0000, "ForeverArsenal"
wrote in
:

"ForeverArsenal" wrote in message
usnet...
Hi.
Could anyone advise please

1 led drawing 10mA off a 12volt car battery,how long would
take to use up 1amp of the battery.

Am I right in saying it would take 100hrs,could someone confirm please.

Amp is current, not battery capacity. That's amp hours (current over
time).

Wikipedia:

The battery capacity that battery manufacturers print on a battery is
the product of 20 hours multiplied by the maximum constant current
that a new battery can supply for 20 hours at 68 F° (20 C°), down to
a predetermined terminal voltage per cell. A battery rated at 100 A·h
will deliver 5 A over a 20 hour period at room temperature.

Your LED is drawing 1/100 amp, so it would draw the same power in 100
hours as a 1 amp load would draw in one hour, or 1 amp hours of
capacity.

Just shows that you cannot trust Wickipedia!
That should read ..


Did you fix it ? Thats what edit is for.



The battery capacity that battery manufacturers print on a battery is
the product of "The hour rating" in hours multiplied by the maximum
constant current that a new battery can supply for "The hour rating"
at 68 F° (20 C°), down to a predetermined terminal voltage per cell. A
battery rated at 100 A·h will deliver 100/(The hour rating) over "The
hour rating" period at room temperature.

"The hour rating" may be 20 it may be 5 depending upon the
manufacturer and the area of the world that the battery is sold in.

The Peukert exponent will mean that the 20 hour rating is NOT 4 times
the 5 hour rating.

The answer to the original question is therefore (because of Peukert).

Based on a 20 hour rated battery a drain of 10ma will reduce the
battery capacity by 1 Ampere Hour in a time that is a hell of a lot
greater than 100 hours.
Just for example based upon a 100Ah battery at a 20 hour rate with a
Peukert of 1.3, a drain of .050A will actually look like .010A.
Therefor a drain of .05A will pull 1Ah in 100 hours.

Richard

On Fri, 02 Jan 2009 14:49:22 GMT, (GregS)
wrote:


Just shows that you cannot trust Wickipedia!
That should read ..


Did you fix it ? Thats what edit is for.



Nope, I worry enough about posting to newsgroups without a flak jacket
on!

Richard