> Russell McMahon wrote:
> > Conclusion:  Battery had suffered an internal stress break at some
> > point internally.

> How do you know this?  Did you actually see something wrong visually?

> It seems all you really know is that the battery is dead, but not why.
> Could something have shorted out near the bottom of the car where it hit,
> then eventually given way when it melted or sagged?  Have you looked at
the
> lines going to the starter and the starter solenoid?  These are often near
> the bottom.

A replacement battery (that I had at hand) immediately worked when
installed. (I took this to the supermarket and installed it en situ. It
needed jump starting as it was marginally charged but then worked normally).

The original battery:

- Now has over 12v at the terminals OC and delivers < 100 mA SC. It is
either flat or high resistance.
- Was initially in excellent condition.
- Is an overly high capacity unit for the vehicle it is in and could until
then crank it 'forever'.
- Failed essentially instantaneously.
- Gave no external evidence of internal energy dissipation. To fully
discharge a well charged very high capacity  battery in the period of a few
minutes would have required substantial energy dissipation.

I think my analysis is probably correct but, of course, I may be wrong.

The unit is a modern "sealed for death" one.
For interest, & if I get round to it I am considering draining the acid,
washing it out with water several times and then hacking the top off to see
if I can find the fault. Safety glasses will be worn. Body armour probably
wont be. Copious water will be at hand.



        Russell McMahon

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