Re: How many volts in a battery
David M wrote:
> On Tue, 29 Nov 2005 00:32:05 +0000, Paul O. rearranged some electrons to
>>"Al Bundy" <MSfortune@mcpmail.com> wrote in message
>>>A 12V lead acid battery should read 12.6VDC with the top charge burned
>>>off. A small load such as the headlights for 30 seconds will relieve
>>>the top charge.
>>>The true test of the battery, however, is a load test to see how the
>>>voltage holds up under load. A bad battery can measure 12.6V and
>>>immediately drop to nothing when a load is placed upon it.
>>Ok, thanks guys, shoulda asked this earlier. My truck wouldn't start this
>>morning, just the racheting sound, or click, click. Put the charger on it
>>and it wasn't drawing a lot of amps so figured it wasn't dead. Checked with
>>the volt meter and it showed 12.47 v which I thought was ok. So I thought it
>>must be something else wrong. Not wanting to buy a new battery when I
>>thought the old one was ok, I decided to have it towed to the dealer and let
>>the extended warranty take care of what ever was wrong. Well guess what was
>>wrong, the battery. My dumb cost me a few bucks.
> A battery with a defective cell (high resistance) can still read good
> voltage with no load on it, but will not provide enough current to turn
> the starter.
There is also the opposite problem; a shorted cell. If the battery is
otherwise good and the engine is fairly easy to turn over; 10.4-11
volts will start the engine with no problem (for a while). The battery
will die rapidly as the good cells will be seeing a constant overcharge.