battery voltage

 My battery at rest is showing 12.3vdc.   Is it good or bad

 

Measuring a battery without a load really tells nothing unless it is low in
voltage.

 

rb wrote:

Andy replies:
   One can't tell from the info available.... I am assuming you are
talking about automotive-type lead acid batteries in the 12V
systems....

1)  Has it been sitting for 5-6 hours since the last charge cycle ?
It takes
     at least that much time for the "space" charge to dissipate for
an
     idle battery.

 2) Terminal voltage as an indication of "state of charge" is
temperature
      dependent.   12.3 is a bit low, but it doesn't mean the batter
is "bad".
      It may mean that the "state of charge" is low and recharging is
      needed.

 3) Your best test is to go and buy a specific gravity tester which
sells
     for two or three bucks at an auto supply section.  While SG is
also
     temperature dependent, it is a much better indication of the
state
     of charge. The instrument will have directions on how to
interpret
    the results.....

  4)  Your best bet is to first measure and record the SG for each
       cell, and then  charge the battery at a low rate, say 3-4 amps,
       for a day.  Then disconnect the charger and measure the SG
again.
       This will let you know if each cell can accept a charge, and
how
        evenly they are charged.....  In an automobile environment,
it's
        usually the end cell closest to the engine block that goes
first.
        I'm not sure why, but I've seen this a lot of times...  Probly
heat....

  5)  Check the water level in the battery.  If you have to top it up,
use
       distilled water, and don't believe any SG readings for a while
since
       the SG tester will pull the "uncharged" water off the top and
not be
      an indication of the true state of charge until use/vibration/
gassing
      has caused the water to fully mix with the electrolyte.....

 Just a few tips.... If you google on  "lead-acid battery
characteristics"
 you can spend a few minutes learning a lot about how they should
be charged and measured.

                   Andy in Eureka, Texas

 
In an automobile while engine is not running, 12.6VDC is considered
good/normal for a 12 volt battery.

--
Dave

How about a tax to support any military conflict/police action over 3 months
old?

An actual war, we can do what's been done in the past.