Battery dies in heat in '97 850 GLT wagon

I live in the Northeast. We have been experiencing some hot weather the
last two weeks. My '97 850 GLT wagon has had a recurring problem.
When I park the car in say a open lot with no shade for 2 to 3 hours in
hottest time of the day and go to start the car i find the battery
dead. It give one last gasp when I turn the key but then is dead. What
is causing the problem? As soon as I put jumper cables on and the
other car is powered on the car immediately goes through it reset -
lights in the dash come on and the digital clock has a bunch of glyphs.
I turn the key and car turns over immediately.
I took it to the Volvo dealer and said the battery is good, the
alternator is good and the starter is good.
I can only guess that the heat has expanded the female battery adaptors
that connect to the post on the battery and causes the connection to
break.
Has anyone experienced this? And what was the solution? Thanks.

 

No auxillary power units being turned on in the sun that could wear the
battery down?

 

No I only have the passive security system that runs, the clock and
that is about it. I do not have any type of addons.

 

I've done a little Googling and found out that heat is very bad for a
battery, even worse than cold.

"In a hot climate, the harshest environment for a battery, a Johnson
Controls survey of junk batteries revealed that the average life of a
good quality car battery was 37 months."
http://www.scoop0901.net/AWAKE/FAQ/Battery/carfaq.htm

Also I read the explanation is:
Temperature will kill a battery over time. If a battery gets too hot,
its self-discharge rate goes up. If the battery gets to cold, the
reaction that produces electricity gets slowed down and the full
capacity cannot be ``harvested.''

It's been averaging between 98-105F where I live (not counting the heat
index), my battery is fairly new so I haven't had any heat problems. I
suspect yours may be a few years old and is dipping just below cranking
amperage in the heat.

 

FWIW, give yourself another sanity check...take a look at:

- glove box light [sometimes the switch doesn't break and/or the door
doesn't close all the way]

- rear tailgate lamp [if the tailgate doesn't close just right, it will
stay on...and if your ~6ft as I am, or don't drive at night usually,
you may not see the illuminated lamp in your rearview

- look at the lamps above each of the rear doors, make sure they are
not in manual override

- you said your battery is new...how new ? make/manuf/CCA ? If it is
indeed a Volvo battery, they run 550-590 avg CCAs, others [Interstate
in particular] run 650+ CCA.

- these things are notorious for ZERO warning on battery failure...one
day fine, MAYBE a little slow on 1 or 2 starts, and then NOTHING

- many of us who live in New England with our extreme temperature
swings replace every 2 [sometimes 3] years

just my $0.02, hope some of this is helpful

Concord, NH

 

....and, so called 'maintenance free' batteries aren't really!
Pop the caps off and see if the plates are exposed. I've found half the
electrolyte gone on batteries less than 2 years old. Refilling with
water will rejuvenate them temporarily, until you can replace it on the
weekend.

 

Not necessarily with the heat, but the symptoms are familiar. I believe the
battery has broken connections inside. Once the connections make contact the
battery tests good. The "last gasp" really sounds like that problem,
especially when you add the car turning over immediately when jumped. Living
in Phoenix I saw that a lot, so maybe heat does have something to do with
it.

A good diagnostic for that (other than swapping batteries with another car)
is to carry a small hammer in the car and when the symptom returns give each
post a whack or two - not hard enough to break the case, of course, but
about what you would do to crack a tough nut. That often restores contact
and allows you to start the car. You can also turn on the lights and watch
to see if they come on when you whack the posts.

If the battery is two or more years old, I wouldn't even bother with that -
I'd put a new battery in. I'm pretty sure that will solve your problem.

Mike