has anyone ever heard of a battery having a dead cell and then turning on
the defense mechanism of the computer so your car won't start? my stepson's
Hyundai accent wouldn't start and i got 12 volts at the battery and at the
wiring harness to the coils. the coils and crankshaft position sensor were
new. the dealer charged him $118.00 for the battery and now it runs ,where
before we got no spark, even if i jumped it with a portable power pack. any
thoughts? thanks
Mike Marlow - 14 Apr 2006 03:27 GMT
> has anyone ever heard of a battery having a dead cell and then turning on
> the defense mechanism of the computer so your car won't start? my stepson's
[quoted text clipped - 3 lines]
> before we got no spark, even if i jumped it with a portable power pack. any
> thoughts? thanks
Yeah, I have a thought. $118 for a car batter is absurd! Tell your stepson
he's got my sympathy for getting ripped off like that.

Signature
-Mike-
mmarlowREMOVE@alltel.net
randy pape - 14 Apr 2006 04:19 GMT
my thoughts exactly. great dealer hey? no wonder i never take my cars in.
Matt Whiting - 14 Apr 2006 15:02 GMT
>>has anyone ever heard of a battery having a dead cell and then turning on
>>the defense mechanism of the computer so your car won't start? my
[quoted text clipped - 12 lines]
> Yeah, I have a thought. $118 for a car batter is absurd! Tell your stepson
> he's got my sympathy for getting ripped off like that.
Yes, if that was the battery alone that is a rip-off. If it was the
total bill for diagnosis and replacement of the battery as well as the
battery, then I'd say it wasn't unreasonable.
Matt
Darby OGill - 14 Apr 2006 10:36 GMT
its my observation that a good12 v battery is really more like almost 13
volts unloaded. Did it light the headlights brightly? Did it blow the hown
loudly? ie Did it adequately power all the other stuff?.....anyways your kid
will probably be more likely to get out a wrench and change it himself next
time around...ps how old was the battery? pps were the terminals/cables
clean and making good contact?...don't know why your portable unit didn't
work.
.
> has anyone ever heard of a battery having a dead cell and then turning on
> the defense mechanism of the computer so your car won't start? my
[quoted text clipped - 3 lines]
> runs ,where before we got no spark, even if i jumped it with a portable
> power pack. any thoughts? thanks
nothermark - 14 Apr 2006 12:51 GMT
>has anyone ever heard of a battery having a dead cell and then turning on
>the defense mechanism of the computer so your car won't start? my stepson's
[quoted text clipped - 3 lines]
>before we got no spark, even if i jumped it with a portable power pack. any
>thoughts? thanks
12 v is too low. It should be around 13.6V.
It's not a case of turning on a "defense mechanism", rather an issue
of not haveing enough voltage to turn on the computer and other
devices. I suspect the voltage would really drop when cranking so
that even if there was enough power to see the dash and light some
lights the voltage level would drop below the sensor and computer
minimums during cranking.
BTW, price would not be that bad. Figure an hour labor plus the cost
of the battery for diagnosis and installation. Dealers have to pay
taxes and eat too.
Matt Whiting - 14 Apr 2006 15:07 GMT
>>has anyone ever heard of a battery having a dead cell and then turning on
>>the defense mechanism of the computer so your car won't start? my stepson's
[quoted text clipped - 5 lines]
>
> 12 v is too low. It should be around 13.6V.
Only if it is on a charger. A resting battery is more like 12.6V if it
is in good shape and depending on temperature.
http://www.buchanan1.net/lead_acid.shtml
Matt
nothermark - 14 Apr 2006 21:53 GMT
>>>has anyone ever heard of a battery having a dead cell and then turning on
>>>the defense mechanism of the computer so your car won't start? my stepson's
[quoted text clipped - 12 lines]
>
>Matt
I don't think I have ever seen a good one run that low but my favorite
source - http://www.batteryuniversity.com/partone-13.htm agrees with
him. That is the minimum though. We always learned that lead acid wa
2.2 v / cell. That does seem more normal.
Either way 12 is too low but we don't know how well that was measured.
By that I mean around 12 on an old mechical meter or 12.053 on a
recently calibrated DVM. It's really too bad he didn't stop by
somebody like Autozone and have it load tested before hitting the
dealer. Testing under load is the only good test as it shows up bad
internal connections as well as charge capacity.
Mark
Matt Whiting - 14 Apr 2006 21:56 GMT
>>>>has anyone ever heard of a battery having a dead cell and then turning on
>>>>the defense mechanism of the computer so your car won't start? my stepson's
[quoted text clipped - 17 lines]
> him. That is the minimum though. We always learned that lead acid wa
> 2.2 v / cell. That does seem more normal.
Where did you learn that? I was always taught (I'm an EE) that 2.1V per
cell was nominal for an LA cell.
Matt
nothermark - 15 Apr 2006 03:36 GMT
>>>>>has anyone ever heard of a battery having a dead cell and then turning on
>>>>>the defense mechanism of the computer so your car won't start? my stepson's
[quoted text clipped - 22 lines]
>
>Matt
E tech - I can't say where I learned it - it was too long ago. perhaps
Navy, perhaps tech school, perhaps etc. Just out of curiosity I went
out and checked the car - 12.69. Checked back to a couple of web
sites. The only thing I can say now is none of the numbers match
exactly. ;-) OTOH discussions like this get me to relearn old
knowledge. It's good to check back on what I think I know every once
in a while.