🚀 go-pugleaf

>My 1983 Datsun MAXIMA's battery (30 months old, 26400 miles) has gone dead
>twice within the past 3 weeks.  The car will readily start with a jump.  There
>have been no warning signs that the battery was weak, no other problems
>starting the car.  It is kept in a garage, so temperature is not a factor.
>The battery is a sealed maintenance-free one so the cells cannot be checked.
>After jumping it the first time, everything was fine until 3 weeks later when
>it was dead again.  The car was run earlier in the day with no incident.  That
>night I measured only 7.5V on the battery after it wouldn't start.  There is a
>voltmeter on the dash rather than an idiot light.  It shows that the battery is
>being charged OK.  I had the charging system checked anyway and it's OK.
>
>Does this sound like a bad battery problem or something more subtle?

After having just been through a similar experience with my car, I put my bet
on the battery.

Maintenance-free batteries can apperently exhibit some strange symptoms when
they're getting ready to die.  Mine appeared to be fine sometimes, nearly
dead (or dead) others.  The charging system appeared to be OK, and load-testing
the battery indicated that it was less than spectacular, but far from dead.
If the car starts readily when jumped, your starter is probably OK.

Try the following test on a weekend:  Hook the battery to a charger at least
overnight, then go out and turn on your headlights for about 15 minutes.
After this, try to start the car.  If it doesn't turn over, or just barely
turns over, you can figure its the battery, otherwise, have the charging
system checked more thoroughly.

Try 

>My 1983 Datsun MAXIMA's battery (30 months old, 26400 miles) has gone dead
>twice within the past 3 weeks....
>...There is a
>voltmeter on the dash rather than an idiot light.  It shows that the battery is
>being charged OK.  I had the charging system checked anyway and it's OK.
>
>Does this sound like a bad battery problem or something more subtle?
>  
>                                               Rick Nelson
>                                               mhuxl!david1

****
You might keep an eye on the voltmeter at night when you have a
lot of things turned on.  Could be you need a new alternator belt.
The belt is turning the alternator during light loads, but when the
load gets heavy and the alternator gets harder to turn, the belt
starts slipping, and you start eating the battery.  Happened to me.
Took it in twice to have the charging system checked, but nothing
wrong.  Except once every 2 or 3 weeks the battery would go dead.
(This is a Pontiac we're talking about, if it makes any difference.)
I finally changed the belt and cinched it tight, and after 6 weeks
didn't have a recurrance of the problem.  A cheap fix.  Try it.

				Ron
-- 
--
		Ronald O. Christian (Fujitsu America Inc., San Jose, Calf.)
		ihnp4!{pesnta,qubix}!wjvax!fai!ronc

Oliver's law of assumed responsibility:
	"If you are seen fixing it, you will be blamed for breaking it."

Another thing to check is whether there is a drain on the 
battery when you think there shouldn't be.  You can check this
with a voltmeter with the engine off.  I had a small but
constant drain from the courtesy light in my glove box -- the
door didn't shut well and the light was always on.  It was only
a problem when the car sat idle for more than 24 hours in a row.

Aaron

Aaron Temin, CS Dept., University of Texas, Austin, Texas
temin@SALLY.UTEXAS.EDU, {ihnp4,seismo,ctvax}!ut-sally!temin

-- 
Aaron Temin, CS Dept., University of Texas, Austin, Texas
temin@SALLY.UTEXAS.EDU, {ihnp4,seismo,ctvax}!ut-sally!temin

In article <411@mhuxl.UUCP> david1@mhuxl.UUCP (Rick Nelson) writes:
>My 1983 Datsun MAXIMA's battery (30 months old, 26400 miles) has gone dead
>twice within the past 3 weeks....

I would first check that the fan belt on the alternator was tight
enough.  It could be that it is slipping somewhat so that the battery
is charging adequately most, but not all, of the time.  Then clean
both the battery terminals and the inside of the battery clamps.
Scrape them clean with a knife or some other type of scraper.  Wire
brushing doesn't always get all of the corrosion off.  Make sure
that you can't, in fact, check the electrolyte level of the battery.
Many of the maintenance-free batteries I've seen state on the battery
that although the battery is designed to be maintenance-free, in
unusual conditions some of the electrolyte may be lost and will
have to be replaced.  I've seen 3 maintenance-free batteries that
needed to have water added to them.  You can also have the battery
load tested at almost any auto service facility.  They test the
battery to see how it takes a charge and how well it responds to a
"starter" load.  This should be cheap.  They should also be able to
cheaply test your charging system.

-- 
Bill Svirsky
Citicorp/TTI
3100 Ocean Park Blvd.
Santa Monica, CA 90405 Work phone: 213-450-9111 x2597
{philabs,randvax,trwrb,vortex}!ttidca!ttidcb!svirsky

"I love it when a plan comes together."
                        Hannibal Smith