Battery draining
05-18-2005, 10:17 PM
#46
Guest
Posts: n/a
Re: Battery draining
On 2005-05-18 loewen_tatyahoo.ca@ said:
>Newsgroups: alt.autos.honda
>Thanks for the info Tom.
>This was a Motomaster Eliminator from Canadian
>Tire up here in Canada. They are notorious for
>being of low quality. I also have one for my 98
>civic, and I have to say I am not impressed, I
>will probably go for a Honda OEM battery next
>time, my original lasted over 8 years!
>However, it is not a maintenance free battery.
>I pulled the caps off, just to make sure the
>water level was good, but did not perform any
>other tests on the electrolytes.
>So the big question here, is 800mA enough to
>drain a battery over night, or a couple days?
>Terry
We don't know what the capacity is, since cranking batteries are
rated in cranking amps.
But, I have a Group 27 fishing battery here, 12" x 6 1/2" x 8" = 624
cu. in., 115 AH capacity.
My mid-80's Civics use a Group 51, 9" x 5" x 8" = 360 cu. in.
Capacity might be proportional to volume. 360 / 624 = .577 x 115 =
66 AH for Civic battery.
If the battery were fully charged (it wasn't), .8 A would discharge
it in 82 hrs.
Based on the terminal voltage reading you gave, I'd guess it was
about 1/3 charged. So you're probably in the ball park.
Crappy batteries usually come with their plates only partially
formed, and need a stiff initial charge. Start at around 10 hr. rate
(capacity / 10), monitor voltage, limit it to 16 V. When current
falls to, probably, 2 A, you're done. Leave the cell caps on, so you
don't get acid sprayed around. (removing caps for charging is an old
mechanic's tale!<G>; so is putting it on a board.)
Don't do this to a sealed battery.
Tom Willmon
near Mountainair, (mid) New Mexico, USA
Judging from the taste, I'd say the other one is shinola.
Net-Tamer V 1.12.0 - Registered
05-18-2005, 10:17 PM
#47
Guest
Posts: n/a
Re: Battery draining
On 2005-05-18 loewen_tatyahoo.ca@ said:
>Newsgroups: alt.autos.honda
>Thanks for the info Tom.
>This was a Motomaster Eliminator from Canadian
>Tire up here in Canada. They are notorious for
>being of low quality. I also have one for my 98
>civic, and I have to say I am not impressed, I
>will probably go for a Honda OEM battery next
>time, my original lasted over 8 years!
>However, it is not a maintenance free battery.
>I pulled the caps off, just to make sure the
>water level was good, but did not perform any
>other tests on the electrolytes.
>So the big question here, is 800mA enough to
>drain a battery over night, or a couple days?
>Terry
We don't know what the capacity is, since cranking batteries are
rated in cranking amps.
But, I have a Group 27 fishing battery here, 12" x 6 1/2" x 8" = 624
cu. in., 115 AH capacity.
My mid-80's Civics use a Group 51, 9" x 5" x 8" = 360 cu. in.
Capacity might be proportional to volume. 360 / 624 = .577 x 115 =
66 AH for Civic battery.
If the battery were fully charged (it wasn't), .8 A would discharge
it in 82 hrs.
Based on the terminal voltage reading you gave, I'd guess it was
about 1/3 charged. So you're probably in the ball park.
Crappy batteries usually come with their plates only partially
formed, and need a stiff initial charge. Start at around 10 hr. rate
(capacity / 10), monitor voltage, limit it to 16 V. When current
falls to, probably, 2 A, you're done. Leave the cell caps on, so you
don't get acid sprayed around. (removing caps for charging is an old
mechanic's tale!<G>; so is putting it on a board.)
Don't do this to a sealed battery.
Tom Willmon
near Mountainair, (mid) New Mexico, USA
Judging from the taste, I'd say the other one is shinola.
Net-Tamer V 1.12.0 - Registered
05-18-2005, 10:17 PM
#48
Guest
Posts: n/a
Re: Battery draining
On 2005-05-18 whybcuzREMOVE@THISyahoo.com said:
>Newsgroups: alt.autos.honda
>> >800 mA/hr is not normal and may get your battery drained
>> >sufficiently enough to not start the next day.
>> >Remco
>> There is no "/hr" in the units for electrical current. "800 mA"
>>is correct.
>You are right in stating that mA/hr should not have been used: I
>started typing something else and forgot to delete the /hr.
>Actually - not to have the last word - but there is a measure called
>Ampere-Hour or Amp/Hr in relation to batteries -
Yeah. But let's drop the Amp/Hr idea. Here's why:
1 Ampere = 1 Coulomb [unit of charge] / second.
Amp / sec. would be Coulomb / sec (squared). That would be something like
acceleration, seldom useful in ordinary electricity. I've never seen it in
engineering work.
>it is in relation
>to the useable capacity of a battery (commonly referred to as C
>rating. ie C/10, C/20 state the discharge rate over time).
>If you draw more current than specified per hour, your battery
>capacity is diminished.
>But batteries are rated at some Amp-Hr. A 80 Amp/Hr battery would
>put out 20 Amps for 4 Hour or 1 Amp for 80 hours before it is
>totally empty.
>Anyway, 800mA is not a normal current draw for a car parked -
>that's what I meant to say.
I agree.
Tom
An oyster is a fish built like a nut.
Net-Tamer V 1.12.0 - Registered
05-18-2005, 10:17 PM
#49
Guest
Posts: n/a
Re: Battery draining
On 2005-05-18 whybcuzREMOVE@THISyahoo.com said:
>Newsgroups: alt.autos.honda
>> >800 mA/hr is not normal and may get your battery drained
>> >sufficiently enough to not start the next day.
>> >Remco
>> There is no "/hr" in the units for electrical current. "800 mA"
>>is correct.
>You are right in stating that mA/hr should not have been used: I
>started typing something else and forgot to delete the /hr.
>Actually - not to have the last word - but there is a measure called
>Ampere-Hour or Amp/Hr in relation to batteries -
Yeah. But let's drop the Amp/Hr idea. Here's why:
1 Ampere = 1 Coulomb [unit of charge] / second.
Amp / sec. would be Coulomb / sec (squared). That would be something like
acceleration, seldom useful in ordinary electricity. I've never seen it in
engineering work.
>it is in relation
>to the useable capacity of a battery (commonly referred to as C
>rating. ie C/10, C/20 state the discharge rate over time).
>If you draw more current than specified per hour, your battery
>capacity is diminished.
>But batteries are rated at some Amp-Hr. A 80 Amp/Hr battery would
>put out 20 Amps for 4 Hour or 1 Amp for 80 hours before it is
>totally empty.
>Anyway, 800mA is not a normal current draw for a car parked -
>that's what I meant to say.
I agree.
Tom
An oyster is a fish built like a nut.
Net-Tamer V 1.12.0 - Registered
05-18-2005, 10:47 PM
#50
Guest
Posts: n/a
Re: Battery draining
> 1 Ampere = 1 Coulomb [unit of charge] / second.
>
> Amp / sec. would be Coulomb / sec (squared). That would be something like
> acceleration, seldom useful in ordinary electricity. I've never seen it
in
> engineering work.
While it isn't used very much in most electrical engineering applications,
the Amp/Hr measure is one way they spec batteries. I agree with you that in
the strictest terms it doesn't make much sense.
You must also have EE or related training -- seems like many of us just come
out of the woodwork when electical stuff comes up, doesn't it?
> An oyster is a fish built like a nut.
I like that saying -- have to remember that one! Thanks!
>
> Amp / sec. would be Coulomb / sec (squared). That would be something like
> acceleration, seldom useful in ordinary electricity. I've never seen it
in
> engineering work.
While it isn't used very much in most electrical engineering applications,
the Amp/Hr measure is one way they spec batteries. I agree with you that in
the strictest terms it doesn't make much sense.
You must also have EE or related training -- seems like many of us just come
out of the woodwork when electical stuff comes up, doesn't it?
> An oyster is a fish built like a nut.
I like that saying -- have to remember that one! Thanks!
05-18-2005, 10:47 PM
#51
Guest
Posts: n/a
Re: Battery draining
> 1 Ampere = 1 Coulomb [unit of charge] / second.
>
> Amp / sec. would be Coulomb / sec (squared). That would be something like
> acceleration, seldom useful in ordinary electricity. I've never seen it
in
> engineering work.
While it isn't used very much in most electrical engineering applications,
the Amp/Hr measure is one way they spec batteries. I agree with you that in
the strictest terms it doesn't make much sense.
You must also have EE or related training -- seems like many of us just come
out of the woodwork when electical stuff comes up, doesn't it?
> An oyster is a fish built like a nut.
I like that saying -- have to remember that one! Thanks!
>
> Amp / sec. would be Coulomb / sec (squared). That would be something like
> acceleration, seldom useful in ordinary electricity. I've never seen it
in
> engineering work.
While it isn't used very much in most electrical engineering applications,
the Amp/Hr measure is one way they spec batteries. I agree with you that in
the strictest terms it doesn't make much sense.
You must also have EE or related training -- seems like many of us just come
out of the woodwork when electical stuff comes up, doesn't it?
> An oyster is a fish built like a nut.
I like that saying -- have to remember that one! Thanks!
05-19-2005, 01:34 AM
#52
Guest
Posts: n/a
Re: Battery draining
<twillmon@cybermesa.net> wrote in message
news:d6gt07$rn6$3@reader2.nmix.net...
> Amp / sec. would be Coulomb / sec (squared). That would be something like
> acceleration, seldom useful in ordinary electricity. I've never seen it
> in
> engineering work.
>
It is a rate of current change, which is meaningful in inductive loads.
Steady amp/sec change across an inductor produces constant voltage, and
vice-versa. In automotive work it would only be used for ignition coils, but
it is the big factor in analyzing whether communication sites get whacked
when lightning strikes. The typical standard for lightning is 10K amp/sec,
simulating a 1000 amp strike with rise time of 0.1 seconds. At those rates
of current rise, a sharp bend in conductors usually causes lightning to
break back out into the air. The inductance of a straight piece of 4/0
welding wire is enough that lightning won't always stay inside, but often
flashes along the surface.
Mike
news:d6gt07$rn6$3@reader2.nmix.net...
> Amp / sec. would be Coulomb / sec (squared). That would be something like
> acceleration, seldom useful in ordinary electricity. I've never seen it
> in
> engineering work.
>
It is a rate of current change, which is meaningful in inductive loads.
Steady amp/sec change across an inductor produces constant voltage, and
vice-versa. In automotive work it would only be used for ignition coils, but
it is the big factor in analyzing whether communication sites get whacked
when lightning strikes. The typical standard for lightning is 10K amp/sec,
simulating a 1000 amp strike with rise time of 0.1 seconds. At those rates
of current rise, a sharp bend in conductors usually causes lightning to
break back out into the air. The inductance of a straight piece of 4/0
welding wire is enough that lightning won't always stay inside, but often
flashes along the surface.
Mike
05-19-2005, 01:34 AM
#53
Guest
Posts: n/a
Re: Battery draining
<twillmon@cybermesa.net> wrote in message
news:d6gt07$rn6$3@reader2.nmix.net...
> Amp / sec. would be Coulomb / sec (squared). That would be something like
> acceleration, seldom useful in ordinary electricity. I've never seen it
> in
> engineering work.
>
It is a rate of current change, which is meaningful in inductive loads.
Steady amp/sec change across an inductor produces constant voltage, and
vice-versa. In automotive work it would only be used for ignition coils, but
it is the big factor in analyzing whether communication sites get whacked
when lightning strikes. The typical standard for lightning is 10K amp/sec,
simulating a 1000 amp strike with rise time of 0.1 seconds. At those rates
of current rise, a sharp bend in conductors usually causes lightning to
break back out into the air. The inductance of a straight piece of 4/0
welding wire is enough that lightning won't always stay inside, but often
flashes along the surface.
Mike
news:d6gt07$rn6$3@reader2.nmix.net...
> Amp / sec. would be Coulomb / sec (squared). That would be something like
> acceleration, seldom useful in ordinary electricity. I've never seen it
> in
> engineering work.
>
It is a rate of current change, which is meaningful in inductive loads.
Steady amp/sec change across an inductor produces constant voltage, and
vice-versa. In automotive work it would only be used for ignition coils, but
it is the big factor in analyzing whether communication sites get whacked
when lightning strikes. The typical standard for lightning is 10K amp/sec,
simulating a 1000 amp strike with rise time of 0.1 seconds. At those rates
of current rise, a sharp bend in conductors usually causes lightning to
break back out into the air. The inductance of a straight piece of 4/0
welding wire is enough that lightning won't always stay inside, but often
flashes along the surface.
Mike
05-19-2005, 04:15 AM
#54
Guest
Posts: n/a
Re: Battery draining
remco wrote:
|| 1 Ampere = 1 Coulomb [unit of charge] / second.
||
|| Amp / sec. would be Coulomb / sec (squared). That would be
|| something like acceleration, seldom useful in ordinary electricity.
|| I've never seen it in engineering work.
|
| While it isn't used very much in most electrical engineering
| applications, the Amp/Hr measure is one way they spec batteries.
I take it you mean Ah (ampere-hours, aka A*h)?
That's a useful measure for capacity. 10Ah means 10A for 1 hour, or 1A for
10 hours.
|| An oyster is a fish built like a nut.
| I like that saying -- have to remember that one! Thanks!
I get ampere-hours, but I don't get that saying. :/
|| 1 Ampere = 1 Coulomb [unit of charge] / second.
||
|| Amp / sec. would be Coulomb / sec (squared). That would be
|| something like acceleration, seldom useful in ordinary electricity.
|| I've never seen it in engineering work.
|
| While it isn't used very much in most electrical engineering
| applications, the Amp/Hr measure is one way they spec batteries.
I take it you mean Ah (ampere-hours, aka A*h)?
That's a useful measure for capacity. 10Ah means 10A for 1 hour, or 1A for
10 hours.
|| An oyster is a fish built like a nut.
| I like that saying -- have to remember that one! Thanks!
I get ampere-hours, but I don't get that saying. :/
05-19-2005, 04:15 AM
#55
Guest
Posts: n/a
Re: Battery draining
remco wrote:
|| 1 Ampere = 1 Coulomb [unit of charge] / second.
||
|| Amp / sec. would be Coulomb / sec (squared). That would be
|| something like acceleration, seldom useful in ordinary electricity.
|| I've never seen it in engineering work.
|
| While it isn't used very much in most electrical engineering
| applications, the Amp/Hr measure is one way they spec batteries.
I take it you mean Ah (ampere-hours, aka A*h)?
That's a useful measure for capacity. 10Ah means 10A for 1 hour, or 1A for
10 hours.
|| An oyster is a fish built like a nut.
| I like that saying -- have to remember that one! Thanks!
I get ampere-hours, but I don't get that saying. :/
|| 1 Ampere = 1 Coulomb [unit of charge] / second.
||
|| Amp / sec. would be Coulomb / sec (squared). That would be
|| something like acceleration, seldom useful in ordinary electricity.
|| I've never seen it in engineering work.
|
| While it isn't used very much in most electrical engineering
| applications, the Amp/Hr measure is one way they spec batteries.
I take it you mean Ah (ampere-hours, aka A*h)?
That's a useful measure for capacity. 10Ah means 10A for 1 hour, or 1A for
10 hours.
|| An oyster is a fish built like a nut.
| I like that saying -- have to remember that one! Thanks!
I get ampere-hours, but I don't get that saying. :/
Thread
Thread Starter
Forum
Replies
Last Post
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)