Honda Car Forum

> >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 - 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.

"disallow" <loewen_t at yahoo.ca @> wrote in message
news:afb46712af047275c15d0ebe6e9c288e@localhost.ta lkaboutautos.com...
> Just got this info from a guy on the Volvo
> group, in case anyone is interested:
>
>> I just happen to have a wire diagram book for '87 handy. That fuse
> only
>> feeds the fuel pump relay. With the key off, check for power at the
>> following: The red-yellow wire at the injectors and the orange wire on
>> pin 5 at the air mass meter. If either have power then the fuel pump
>> relay is stuck in the on position and you need a new one.
>>
>> Also, assuming the battery is fully charged, then this draw shouldn't
>> kill it in 10 hours. However, car batteries aren't designed for this
>> kind of discharge/recharge and can be quickly damaged when subjected to
>> it.
> Mike F. Thornhill ON
>

Super! Mike F is the top guru on Volvos.

Mike

"Michael Pardee" <michaeltnull@cybertrails.com> wrote in message
news:OqydnZlj9PEvphbfRVn-ig@sedona.net...
> "remco" <whybcuzREMOVE@THISyahoo.com> wrote in message
> news:_2Gie.12210$yx.81@fe08.lga...
>> >
>>> After taking all of your advice, we found nuthin!
>>>
>>> BUT, there is this blade fuse in line with a wire
>>> coming directly off of the positive terminal of
>>> the battery. Apparently, it feeds the fuel pump
>>> relay. Its a 30 Amp fuse.
>>>
>>> Anyways, when I pulled that fuse, the draw on the
>>> battery went from 0.87amps to 0.01amps. I'm
>>> thinking my problem is there.
>>>
>>> Any ideas on how to fix this? Once the power goes
>>> to the relay, where would it go from there?
>>
>> Seems odd that they'd fuse a fuel pump with 30Amps and feed it directly
>> off
>> the battery since a a fuel pump doesn't take very much power to run.
>> Power
>> delivery (ie power drop across wires, requiring fat wires) is usually not
>> a
>> problem.
>>
>> My old volvo was an older model and don't remember if they had direct
>> line
>> going to the pump.
>> What is more logical is that this fuses the alternator. An alternator is
>> usually directly connected to the battery. It does have diodes inside
>> that
>> short and cause current to flow when it shouldn't. Can you follow that
>> wire
>> to see where it goes?
>>
>> Also, I'd imagine that if that fat wire and fuse indeed do feed the pump
>> through a relay, it would most likely be connected to the contact of the
>> relay (the switch side) -- there's no point connecting a high current
>> wire
>> to the coil (actuator side) of the relay as that is definitely low
>> current.
>> That being true, the only way that you can have any appreciable current
>> running is if the pump is running, even with the car shut off. That relay
>> must be driven somehow.
>>
>> I'd still first check to make sure that that fat wire/fuse is not
>> connected
>> to the alternator, though..
>>
>> Remco
>>
>>
>>
> Nope - the fuse is for the fuel pumps. There is a small in-tank impeller
> pump that draws a little under an amp and a main pump under the car below
> the driver's seat that typically draws a bit under 10 amps... probably
> more on startup. Both are controlled by separate sections of the fuel pump
> relay. The in-tank pump is on any time the ignition is on, while the main
> pump is timer controlled.
>
> The alternator is not fused.
>
> Mike
>
Sounds like a bad fuel pump relay, the in tank impeller pump side welded
closed, main pump contact working normally.

Have Fun,
John

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

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

> 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!

<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

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. :/