Battery Drain?

I have a 91 prelude 5 speed, The battery keeps going dead! I
disconnected the positive lead and the battery holds it charge. With
the engine running there is 14.5 volts charging the batery. If I
disconnect the battery and check for a amperage draw there is a .03
amp drain. I thought maybe the alternator was the problem so I
disconnected the main positive lead off the alternator.
That made no differance. Any suggestions?

On Jul 30, 12:48 am, wrote:
> I have a 91 prelude 5 speed, The battery keeps going dead! I
> disconnected the positive lead and the battery holds it charge. With
> the engine running there is 14.5 volts charging the batery. If I
> disconnect the battery and check for a amperage draw there is a .03
> amp drain. I thought maybe the alternator was the problem so I
> disconnected the main positive lead off the alternator.
> That made no differance. Any suggestions?

There are a LOT of things on cars today that stay on even when
ignition is off. These are supposed to be very low drain, and battery
should last for a week or two between use. If storing a car for a long
time, yeah, then they recommend removing battery lead.

What usually happens is that one of those systems left connected has
gone bad, and now represents a high drain. Are any accessories not
working? That might be suspect. Radio is one system that stays
connected so memory can remember station presets and last selected
station. Engine control computer is another. If you have a seperate
digital clock (not part of radio) that stays connected. I believe on
many cars power is left on to the headlight relay, relying on lack of
control signal to keep relay off when power off. But a bad relay can
draw current (I've had that one happen).

I wish auto and radio mfgs would go to flash memory so they would not
need battery power to keep these "memories" alive.

"Don Stauffer in Minnesota" > wrote in message
oups.com...
> On Jul 30, 12:48 am, wrote:
>> I have a 91 prelude 5 speed, The battery keeps going dead! I
>> disconnected the positive lead and the battery holds it charge. With
>> the engine running there is 14.5 volts charging the batery. If I
>> disconnect the battery and check for a amperage draw there is a .03
>> amp drain. I thought maybe the alternator was the problem so I
>> disconnected the main positive lead off the alternator.
>> That made no differance. Any suggestions?
>
> There are a LOT of things on cars today that stay on even when
> ignition is off.

Exactly, Don.

Now, if he is only drawing 30 milliamperes, that is not much and the battery
should last for a good while. He is apparently not getting this kind of
charge life, and I can appreciate it because I have the same problem on
my Reatta.

What is happening, in my case, is that intermittently some other system
comes
on and the drain goes from 0.03-0.04 amperes up to a much higher number,
several amps likely, running the battery down. When I go back to check it,
the car may well be drawing the low figures again.

These faults are hard to find, sometimes. I have bought a VOM which will
record the maximum current drain, and had planned to go down the schematic,
removing branches until I find the culprit.

Now, I think my wife may have found the culprit without all that. In the
middle
of the night a few days ago, she woke up and saw the tail lights go on.
This
was a lucky observation for me.

Our OP may have to trace this thing out the hard way.

I always pull one of the battery (I think it's the positive one) cables
off when I park my 1978 Dodge van in my driveway.I have an old battery
cable tied in there.I always let it drape out of there.
cuhulin

> wrote in message
...
>I always pull one of the battery (I think it's the positive one) cables
> off when I park my 1978 Dodge van in my driveway.I have an old battery
> cable tied in there.I always let it drape out of there.
> cuhulin

I have a couple of battery disconnects that I use in my cars. They are
relatively
cheap, at WalMart.

Still, there is nothing like having a car that works the way is it supposed
to.

> wrote: (91 prelude 5 speed)

The battery keeps going dead.

__ If I disconnect the positive cable the battery holds its charge.
So the battery is okay - the drain is not internal.

__ With the engine running there is 14.5 volts charging the battery.
So the alternator voltage regulation is okay - it is normal.

__ Disconnecting the main positive alternator lead makes no difference.
So the alternator diodes are not the source of the drain.

__ If I disconnect the battery there is a .03 amp drain.
Thirty milliamps to run clocks and memory chips is not much.
..03 amps x 24 Hours = 0.72 Ampere-hours, not enough to
drain a car battery in one day.

__ Any suggestions?
Post again with more information, including how you measure
amperage drain with the battery disconnected.

Good luck.

Rodan.

On Tue, 31 Jul 2007 19:44:38 GMT, Rodan > wrote:


> > wrote: (91 prelude 5 speed)

>The battery keeps going dead.

>__ If I disconnect the positive cable the battery holds its charge.
>So the battery is okay - the drain is not internal.

>__ With the engine running there is 14.5 volts charging the battery.
>So the alternator voltage regulation is okay - it is normal.

>__ Disconnecting the main positive alternator lead makes no difference.
>So the alternator diodes are not the source of the drain.

>__ If I disconnect the battery there is a .03 amp drain.
>Thirty milliamps to run clocks and memory chips is not much.
>.03 amps x 24 Hours = 0.72 Ampere-hours, not enough to
>drain a car battery in one day.

>__ Any suggestions?

If you disconnect the battery, how is there a 0.03 amp drain?

How much of a drain is there with the battery installed? Is the battery
clean? Could there be acid/crud from the positive terminal to a nearby
ground?

Use a spoonful or two of baking soda in a cup of warm water and a rag or
a few paper napkins and clean the battey off real good, then flush the
battery off with fresh water.That should clean the crud off.
cuhulin

"AZ Nomad" > wrote in message
> If you disconnect the battery, how is there a 0.03 amp drain?
>
> How much of a drain is there with the battery installed? Is the battery
> clean? Could there be acid/crud from the positive terminal to a nearby
> ground?

I read his post to mean that he removed a cable and put the ammeter in
series. Maybe I was wrong. If he just disconnected the battery, he
couldn't have measured any drain. A drain via surface electrolyte is not
measurable that way.

To me, it all still points to some other system being activated,
intermittently,
that runs his battery down.

I had a Buick that nearly drove me crazy with this. Every morning the
battery
was dead, or nearly so. After trying all the simple things, I finally
caught this
car "in delicto flagrante": the seat belt retractors started activating
while the
car was off and parked, and that was enough to run down the battery
overnight.
Very intermittent.

My Reatta also runs down (usually showing 30 - 40 ma parasitic drain),
but I dont drive this car much and I havent spent the time to dig into this
electronic nightmare.