Originally Posted by
fitliker
The load meter will give you a clue as to the health of the battery , the volt drop during start on some engines can be a limit and too big a drop might indicate time to replace the battery or abort the start as it may not be enough power left in the battery to do a healthy start on some turbines .
I concur. The battery voltage might look OK once the generator has topped it off and it is running under normal load. But the high draw from a start can cause the voltage of an individual weak battery cell to collapse. And a low voltage battery (following a start) will draw more power from the generator until that cell (or several cells) have been brought back from near zero volts.
In addition to the battery, this condition can place added strain on the generator, having to supply a higher then normal current until the weak cells are topped off. A good mechanic should be able to load test the battery. Switching on electrical loads with no running generator and watching how fast the battery voltage drops.