Must hold a record now two posts same thread deleted.
Alarm, but bored of nuggets
February 2011
an ordinary test meter cannot test a battery properly,we use a act tester,this measures the voltage,ampage,temperture,and gives a true reading of the state of the battery,but its only pros who buy them because its very expensive,
gts
February 2011
amat victoria curam!
gts
February 2011
As a battery runs down the terminal voltage drops. 13V on a 12V battery sounds good.
A 12V battery showing 12V off load may still be "on the edge" - apply a load to it (draw some current) and the voltage will suddenly fall. If the voltage remains the same then the battery is still good - provided that the current draw is within the range of the battery.
Many multi-meters have both a DC Voltage range and a Battery Test range - the battery test range draws some current to "test" the battery under load conditions.