[Miata] Battery dead then live again??

[John Freas]

Previously on Battery, Butch Garcia <butchgarcia at earthlink.net> said...

 I left my miata parked for two days.  Well my battery died (no lights, no
> radio, battery terminals tight-- it is an autozone battery which seems to
> have been made by WestCo), and so I jump started it according to the
> procedures outlined in Miata.net.  I drove around for about 1/2 hr and then
> killed the engine when I got some gas. It wouldn't turn over.  I was pushed
> started and all was fine.  Drove the car and let it idle for about 1/2 hour
> more.  Came home turned off the engine, and tried to start it; it wouldn't
> turn.  So I ordered a WestCo battery.  The battery arrived a day after and I
> didn't get to try to install the battery 'till a day later or two days after
> I parked the car.  I tried to start it once more with the old battery and it
> started, and has been working well since.  Has this happened to anyone
> else?  Do you have an explanation for this?  Should I be looking for
> something else?
>

Your description of what you did to the battery is a bit confusing.  If you
followed the directions on miata.net then you didn't jumpstart the battery
or car, you put a 2 amp charge on it for 24 to 48 hours to fully charge it.
Jump starting the car will do *nothing* for a flat AGM battery.

If you indeed jump started the car and then let it idle for a half hour (or
hour, or day, or year) it did absolutely nothing to charge the battery.

If you actually charged the battery at 2 amps for 24+ hours and it still
behaved as you describe, then something else is up.  It is possible that you
have a loose connection somewhere.  I cannot explain why it would suddenly
start working again on its own unless there was a problem with a connection
somewhere, maybe in the key switch; that's a common failure point especially
if you have a bunch of keys on a ring.  The Mazda ignition switch isn't
known for it's robustness and the weight from a keyring can cause it to
fail, at first intermittently.

If have another "dead battery"  issue in the future, especially if there is
no obvious cause (lights left on, etc.) then I'd start by checking the
voltage at the battery with a meter.  If it shows normal voltage then
something else is up.  You might try wiggling the ignition switch a few
times and/or turning it on and off repeatedly to see if that has any
effect.  I'd also take the car key off the ring if it's on one, but that's
just me.

    -John
------------------------------
John Freas <%20john7690 at comcast.net>
1992 *YELLOW* "Sting<http://john.freas.home.comcast.net/pix/sting/sting.html>
"
1995 Black R Package
"Spike<http://www.geocities.com/clash_girl/Spike_Scrapbook.html>
"
Elizabethtown, Indiana
- Standard Disclaimer
<http://john.freas.home.comcast.net/disclaimer.html>Applies -
Team LS1,2, SP, the Gap...
I love my Miata
girl<http://www.geocities.com/clash_girl/Spike_Scrapbook.html>and my
Miata Baby
"I have no idea what those dimple things on the windshield frame are for."
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