1982 Prelude has 4v battery drain?

I bought a 1982 Prelude in ... 1982. I live in Virginia where
rusting is minimal, and I have painted it twice, with a little
bit of body work each time. 'Only drive a little and have just
113K miles on it.

Last weekend, my battery died three years into a six year
warranty. Merchants wouldn't honor the warranty because there is
a 4 volt drain on the battery, even when the car is off.

My regular mechanic put his meter on it, and while it wouldn't
even light the test light, it did show 4 volts, the needle
visibly ticking in time with the old analog clock the '82 boxes
used, with the (still faithfully rotating, on time)
white-on-black numerical display. According to my man, the analog
clock, combined with what little memory the add-on Sony
cassette/radio player uses for its memory, could draw 4 volts. He
said more modern cars with more electronics support even more
drain, and he'd have sold me a battery, with full warranty, for
$59. Merchants put in their new battery "pro-rated" for $54, but
, but "no warranty" due to the "battery-killing" drain.

Does this ring true to anyone here? Apart from keeping it looking
and running good, I'm a self-confessed car dunce.

Many thanks,

Travis

 

Hi,
Doesn't sound like battery is bad.
Something else is loading it down. Time to find it by removing fuses
one at a time. Then you can noarrow down possible sosurce of trouble.
Tony

 

There are some problems with the diagnosis. You do not measure battery
drain in volts. You measure the current draw in Amps. If it were 4 Amps,
it would completely drain the battery in less than a day, and your test
light would light up nice and bright. Perhaps he meant 4 mA (milliamps).
That would be the right order of magnitude for a clock, and it would
cause no harm whatsoever. In fact, most newer cars will draw 5 times
that with the ignition off.

 

Everything on a 12V car battery directly gets 12V. Do you mean 4
amps, or milliamps? 4 mA isn't much. 4 amps is an aweful lot for a
car in the off state.

 

Drain is measured in amps (or fractions thereof)

Disconnect the clock fuse and see what happens.

A friend had a 70? Chevy that would discharge the battery overnight. His
clock didn't work, but when we checked the circuit, there was a
substantial draw on it. We disconnected the fuse and everything was fine.

I'm suprised your clock works like that. At least the older "American"
clocks were a wind up type that took a "shot of current" to rewind the
spring every few (5-7???) minutes. Maybe the clock is messed up and
requires a "constant shot"

 

Thanks so much for all the conscientious feedback.

Both Merchants, the battery seller, and my regular garage guy
insist on drain measured as "4 volts" with the car shut off. The
regular man says that's common, and that more modern cars have
way more draw than that when off. "Leave it undriven for
two/three months and, yeah, they'll drain at a few volts. But two
days?!" (Battery failed over a weekend.)

I've had the car 22 years and never had any particular
problem with batteries. If it's a real drain problem, it sure
cropped up awfully quickly.

And conveniently for Merchants. They were recently acquired. New
rules are in effect. Among the reasons listed on my refusal to
warranty were "has melted wires" (20-year-old, but still-sticky
when hot, black stuff dripped on wires below a connection block
of some kind just left of the battery) and "cooling fan runs
longer than should once vehicle is turned off" which goes back to
the purchase of the vehicle in 1982. It was some sort of package
from the dealer, and occasionally someone will tell me, "Your car
is still running" as I leave the parked car. It blows for maybe
five minutes after a ride.

In other words, Merchants seemed to be looking for reasons not to
honor an old warranty, or establish a new one. If I get
sufficient gumption, I'll seek out an electrical specialty shop.
At present, it seems more like the good old run-around.

Thanks again, everyone!

Travis

 

They are both wrong. Talking about a 4 Volt drain is meaningless. This
is one of the few areas where I actually know what I am talking about,
electronics has been my profession for 14 years.

They are still bound by the agreement in place when you bought the
battery. Of course that agreement could state that they can change the
agreement any time they like for any reason, in which case it isn't much
of a warranty.

 

Thanks, Randolf,

I'll give my guy a grilling on the "volts" thing. How odd.

As for fine print in the warranty, I think of all those "Accept"
buttons I click installing software and wonder, "what the hell is
in there?" The consumer is on the receiving end of the big red
One in this department.

Travis

 

In fairness to the mechanics, most of the time they know what they are
doing. My guess is that they measured correctly but messed up on the
measuring units when telling you the result.

 

I dont check up on these newsgroups often anymore,
but this seemed like you both dont understand each other.
One of you is talking about current drain, the one you'd measure with an
amperemeter when the car is off... which over time results in a drop in
voltage, in this case a 4V drop from 13V (or whatever) to 9V lets say... I
think thats what the mechanic meant.

The car battery is not "perfect", it doesnt magically keep a 13V potential
until the energy is depleted. A relatively high current draw to the alarm
system or whatnot would drain the battery, which could be "diagnosed" by
verifying the potential diff at it's terminals. Or for the smarter person,
simply turning on your headlights.

 

Why would it magically stop at 9V? If there's a substantial current drain,
it's going to stop at 0V, no magic about it!