X-Mozilla-Keys:                                                                                 
F. Marc de Piolenc wrote:

Paul wrote:

Ken Powell wrote:

     1.  Is low voltage a sure sign of impending failure (provided the rest
     of the charging system is healthy)?

If battery voltage remains low in spite of an APPARENTLY healthy
charging system (and fluid levels are okay), the only way that I know to
really settle the matter is to disconnect the suspect battery and
replace it with one that is known to be good, then measure bus voltages
during charge. If voltage is still low, the problem is with the charging
system. If voltage quickly reaches cutoff, then the suspect battery is
bad - probably shorted internally.

     2.  How about specific gravity?  Do the testers that float the little
     balls work?

They work, but are not very accurate. Better to get the float-type
battery hydrometer. It is sufficiently accurate to not only allow you to
diagnose the overall state of your battery, but also to find the sick
cell, if there is one.

     3.  Just what are the 'load testers' used at the parts / tire stores
     and how do they work?  Where can I buy one of these?

They put a calibrated resistance in series with the battery and measure
voltage while the battery is feeding that load. This is a much more
accurate measure of battery "health" than open-circuit voltage.

     My concern is having what I think are 2 healthy batteries, only to
     find that they have only about 20% storage.  This will not last long
     with an EFI fuel pump sucking on it.

No kidding!

Best,
Marc de Piolenc

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