Parasitic Drain - Bulb Trick

sharx333 wrote:
> Just wanted to ask:
>
> Is the "light bulb" test (putting a 12v bulb in series with the battery
> circuit) an accurate test for a parasitic drain? My ammeter only goes
> up to 0.25A, and I don't want to risk overloading the meter.
>
> How bright should the bulb light up, if it should at all, for a
> "normal" drain? (clock, ECU, radio memory)
>
> Thanks!
>
sure, but it depends on the bulb and the drain!!! if you describe your
problem, maybe we can address that question better?
 >> Stay informed about: Parasitic Drain - Bulb Trick 

sharx333 wrote:
> Just wanted to ask:
>
> Is the "light bulb" test (putting a 12v bulb in series with the battery
> circuit) an accurate test for a parasitic drain? My ammeter only goes
> up to 0.25A, and I don't want to risk overloading the meter.
>
> How bright should the bulb light up, if it should at all, for a
> "normal" drain? (clock, ECU, radio memory)
>
> Thanks!
>
sure, but it depends on the bulb and the drain!!! if you describe your
problem, maybe we can address that question better?
 >> Stay informed about: Parasitic Drain - Bulb Trick 

sharx333 wrote:
> Just wanted to ask:
>
> Is the "light bulb" test (putting a 12v bulb in series with the battery
> circuit) an accurate test for a parasitic drain? My ammeter only goes
> up to 0.25A, and I don't want to risk overloading the meter.
>
> How bright should the bulb light up, if it should at all, for a
> "normal" drain? (clock, ECU, radio memory)
>
> Thanks!
>
sure, but it depends on the bulb and the drain!!! if you describe your
problem, maybe we can address that question better?
 >> Stay informed about: Parasitic Drain - Bulb Trick 

sharx333 wrote:
> Just wanted to ask:
>
> Is the "light bulb" test (putting a 12v bulb in series with the battery
> circuit) an accurate test for a parasitic drain? My ammeter only goes
> up to 0.25A, and I don't want to risk overloading the meter.
>
> How bright should the bulb light up, if it should at all, for a
> "normal" drain? (clock, ECU, radio memory)
>
> Thanks!
>
sure, but it depends on the bulb and the drain!!! if you describe your
problem, maybe we can address that question better?
 >> Stay informed about: Parasitic Drain - Bulb Trick 

sharx333 wrote:
> Just wanted to ask:
>
> Is the "light bulb" test (putting a 12v bulb in series with the battery
> circuit) an accurate test for a parasitic drain? My ammeter only goes
> up to 0.25A, and I don't want to risk overloading the meter.
>
> How bright should the bulb light up, if it should at all, for a
> "normal" drain? (clock, ECU, radio memory)
>
> Thanks!
>
sure, but it depends on the bulb and the drain!!! if you describe your
problem, maybe we can address that question better?
 >> Stay informed about: Parasitic Drain - Bulb Trick 

"sharx333" <emil.santos.RemoveThis@gmail.com> wrote in news:1163212200.212648.320350
@k70g2000cwa.googlegroups.com:

> Just wanted to ask:
>
> Is the "light bulb" test (putting a 12v bulb in series with the battery
> circuit) an accurate test for a parasitic drain? My ammeter only goes
> up to 0.25A, and I don't want to risk overloading the meter.
>
> How bright should the bulb light up, if it should at all, for a
> "normal" drain? (clock, ECU, radio memory)
>


See the relevant page at Bill Darden's excellent Battery FAQ:
http://www.uuhome.de/william.darden/carfaq10.htm



--
TeGGeR®

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/
 >> Stay informed about: Parasitic Drain - Bulb Trick 

In rec.autos.makers.honda sharx333 <emil.santos DeleteThis @gmail.com> wrote:
> Is the "light bulb" test (putting a 12v bulb in series with the battery
> circuit) an accurate test for a parasitic drain? My ammeter only goes
> up to 0.25A, and I don't want to risk overloading the meter.


I had a light bulb that was a parasitic drain, once.
I thought I just had a dying battery. It was a little sluggish starting
sometimes, and dead if I didn't drive it every day.
I bought a new battery, and that made things much better, and then it was
dead again after it sat for a few days.
I charged it up, got in, and noticed a strange glow on the floor. At first
I thought it was a street light, then I realized that the glove box light
was on. The switch had gotten knocked out of it's mounting. I didn't see
the dim light under daytime conditions, and only happened to notice it at
night.

> How bright should the bulb light up, if it should at all, for a
> "normal" drain? (clock, ECU, radio memory)

I would say that a dual filament 1157 bulb should glow dimly. If it is at
all bright, that is a pretty good load. At full brightness:

bright filament: 12.8V, 26.9W, 2.10A (R=V/I=12.8/2.1=6.1 ohms)
dim filament: 14.0V, 8.3W, 0.59A (R=24 ohms)

--
---
Clarence A Dold - Hidden Valley Lake, CA, USA GPS: 38.8,-122.5
 >> Stay informed about: Parasitic Drain - Bulb Trick 

In rec.autos.makers.honda sharx333 <emil.santos.DeleteThis@gmail.com> wrote:
> Is the "light bulb" test (putting a 12v bulb in series with the battery
> circuit) an accurate test for a parasitic drain? My ammeter only goes
> up to 0.25A, and I don't want to risk overloading the meter.


I had a light bulb that was a parasitic drain, once.
I thought I just had a dying battery. It was a little sluggish starting
sometimes, and dead if I didn't drive it every day.
I bought a new battery, and that made things much better, and then it was
dead again after it sat for a few days.
I charged it up, got in, and noticed a strange glow on the floor. At first
I thought it was a street light, then I realized that the glove box light
was on. The switch had gotten knocked out of it's mounting. I didn't see
the dim light under daytime conditions, and only happened to notice it at
night.

> How bright should the bulb light up, if it should at all, for a
> "normal" drain? (clock, ECU, radio memory)

I would say that a dual filament 1157 bulb should glow dimly. If it is at
all bright, that is a pretty good load. At full brightness:

bright filament: 12.8V, 26.9W, 2.10A (R=V/I=12.8/2.1=6.1 ohms)
dim filament: 14.0V, 8.3W, 0.59A (R=24 ohms)

--
---
Clarence A Dold - Hidden Valley Lake, CA, USA GPS: 38.8,-122.5
 >> Stay informed about: Parasitic Drain - Bulb Trick 

In rec.autos.makers.honda sharx333 <emil.santos DeleteThis @gmail.com> wrote:
> Is the "light bulb" test (putting a 12v bulb in series with the battery
> circuit) an accurate test for a parasitic drain? My ammeter only goes
> up to 0.25A, and I don't want to risk overloading the meter.


I had a light bulb that was a parasitic drain, once.
I thought I just had a dying battery. It was a little sluggish starting
sometimes, and dead if I didn't drive it every day.
I bought a new battery, and that made things much better, and then it was
dead again after it sat for a few days.
I charged it up, got in, and noticed a strange glow on the floor. At first
I thought it was a street light, then I realized that the glove box light
was on. The switch had gotten knocked out of it's mounting. I didn't see
the dim light under daytime conditions, and only happened to notice it at
night.

> How bright should the bulb light up, if it should at all, for a
> "normal" drain? (clock, ECU, radio memory)

I would say that a dual filament 1157 bulb should glow dimly. If it is at
all bright, that is a pretty good load. At full brightness:

bright filament: 12.8V, 26.9W, 2.10A (R=V/I=12.8/2.1=6.1 ohms)
dim filament: 14.0V, 8.3W, 0.59A (R=24 ohms)

--
---
Clarence A Dold - Hidden Valley Lake, CA, USA GPS: 38.8,-122.5
 >> Stay informed about: Parasitic Drain - Bulb Trick 

In rec.autos.makers.honda sharx333 <emil.santos DeleteThis @gmail.com> wrote:
> Is the "light bulb" test (putting a 12v bulb in series with the battery
> circuit) an accurate test for a parasitic drain? My ammeter only goes
> up to 0.25A, and I don't want to risk overloading the meter.


I had a light bulb that was a parasitic drain, once.
I thought I just had a dying battery. It was a little sluggish starting
sometimes, and dead if I didn't drive it every day.
I bought a new battery, and that made things much better, and then it was
dead again after it sat for a few days.
I charged it up, got in, and noticed a strange glow on the floor. At first
I thought it was a street light, then I realized that the glove box light
was on. The switch had gotten knocked out of it's mounting. I didn't see
the dim light under daytime conditions, and only happened to notice it at
night.

> How bright should the bulb light up, if it should at all, for a
> "normal" drain? (clock, ECU, radio memory)

I would say that a dual filament 1157 bulb should glow dimly. If it is at
all bright, that is a pretty good load. At full brightness:

bright filament: 12.8V, 26.9W, 2.10A (R=V/I=12.8/2.1=6.1 ohms)
dim filament: 14.0V, 8.3W, 0.59A (R=24 ohms)

--
---
Clarence A Dold - Hidden Valley Lake, CA, USA GPS: 38.8,-122.5
 >> Stay informed about: Parasitic Drain - Bulb Trick 

In rec.autos.makers.honda sharx333 <emil.santos.DeleteThis@gmail.com> wrote:
> Is the "light bulb" test (putting a 12v bulb in series with the battery
> circuit) an accurate test for a parasitic drain? My ammeter only goes
> up to 0.25A, and I don't want to risk overloading the meter.


I had a light bulb that was a parasitic drain, once.
I thought I just had a dying battery. It was a little sluggish starting
sometimes, and dead if I didn't drive it every day.
I bought a new battery, and that made things much better, and then it was
dead again after it sat for a few days.
I charged it up, got in, and noticed a strange glow on the floor. At first
I thought it was a street light, then I realized that the glove box light
was on. The switch had gotten knocked out of it's mounting. I didn't see
the dim light under daytime conditions, and only happened to notice it at
night.

> How bright should the bulb light up, if it should at all, for a
> "normal" drain? (clock, ECU, radio memory)

I would say that a dual filament 1157 bulb should glow dimly. If it is at
all bright, that is a pretty good load. At full brightness:

bright filament: 12.8V, 26.9W, 2.10A (R=V/I=12.8/2.1=6.1 ohms)
dim filament: 14.0V, 8.3W, 0.59A (R=24 ohms)

--
---
Clarence A Dold - Hidden Valley Lake, CA, USA GPS: 38.8,-122.5
 >> Stay informed about: Parasitic Drain - Bulb Trick 

In rec.autos.makers.honda sharx333 <emil.santos RemoveThis @gmail.com> wrote:
> Is the "light bulb" test (putting a 12v bulb in series with the battery
> circuit) an accurate test for a parasitic drain? My ammeter only goes
> up to 0.25A, and I don't want to risk overloading the meter.


I had a light bulb that was a parasitic drain, once.
I thought I just had a dying battery. It was a little sluggish starting
sometimes, and dead if I didn't drive it every day.
I bought a new battery, and that made things much better, and then it was
dead again after it sat for a few days.
I charged it up, got in, and noticed a strange glow on the floor. At first
I thought it was a street light, then I realized that the glove box light
was on. The switch had gotten knocked out of it's mounting. I didn't see
the dim light under daytime conditions, and only happened to notice it at
night.

> How bright should the bulb light up, if it should at all, for a
> "normal" drain? (clock, ECU, radio memory)

I would say that a dual filament 1157 bulb should glow dimly. If it is at
all bright, that is a pretty good load. At full brightness:

bright filament: 12.8V, 26.9W, 2.10A (R=V/I=12.8/2.1=6.1 ohms)
dim filament: 14.0V, 8.3W, 0.59A (R=24 ohms)

--
---
Clarence A Dold - Hidden Valley Lake, CA, USA GPS: 38.8,-122.5
 >> Stay informed about: Parasitic Drain - Bulb Trick 

Sure, jim. And thanks.

Last week, the battery drained overnight on my '95 Civic 1.6L. I took
the battery to be recharged at a shop, and we found that the water
level was low. But I suspected a "ground" somewhere, because I had just
sprayed the engine with a degreaser and rinsed it (low pressure garden
hose).

Since my ammeter only goes up to 0.25A (250 mA), and I read on some
posts that the current could go over 1A, I tried the bulb trick first.
I don't know the exact rating of the bulb (aftermarket dome/trunk
light), but it glowed brightly. (All doors/trunk was closed, key off)

I tried pulling underhood fuses and even disconnecting the alternator,
with no result. Then I tried pulling the cabin fuses, and I found that
it was the Pioneer head unit that was pulling most of the power (for
the preset memory, I guess).

When I disconnected the radio, the bulb was finally very dim. I tried
the ammeter and expected less than 80 mA (from the battery FAQ link,
thanks to TeGGer). But I still got 170 mA or so. I've checked all the
possible bulbs, and I think a bulb would pull more than that.

I finally concluded that there was no parasitic drain at all, but I'm
puzzled as to what could be making that extra load.
 >> Stay informed about: Parasitic Drain - Bulb Trick