On Sep 2, 1:46pm, "W. Ray Gibbons" wrote:
> I experienced a breakdown recently that represented something new in 38
> years of driving; [...]
>
> I was house-sitting for a friend, and as I approached her house on a
> moderately bumpy gravel road, my 87 Prelude's engine stopped running. [...]
>
> I tentatively concluded that there had been a sudden internal failure of
> some sort in the battery (top of the line Interstate, 3.5 yrs old). To
> make life more interesting, something about the problem was intermittant,
> because the car originally stopped running, whereas after a little
> fiddling with the battery, the car would not start, but would keep
> running. I suspected an internal failure that intermittantly became a
> dead short.
Yes, car batteries do occasionally suffer from internal shorts, caused by cell
sulfation sloughing off the plates, or heat related (over current) plate
distortion, or just plain internal construction defects. But this usually
only affects one cell, and the symptom is usually just an almost dead battery.
It usually doesn't affect the running of the engine, since with 1 shorted
cell, the alternator (or generator, er, dynamo) is really trying to charge a
10V battery (or a 6V and a 4V battery for you pre-70whatever MGB pilots ;^).
Even though this may over-stress the charging system some, 10V is usually
enough to keep the engine running.
-Pat "fire & brimstone" Vilbrandt
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Pat Vilbrandt Fluke Corporation Everett, Washington USA
pwv@tc.fluke.COM or: { uunet, uw-beaver, sun, microsoft }!fluke!pwv
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