[COLVERT]

Originally Posted by Comfortably Numb

12.7V is a more than adequate starting voltage, damage is likely to occur if it is regularly allowed to discharge to around 12.2V or less, and it is also likely to present starting problems at such a low voltage, and discharge the battery further, into the damagingly low realms where sulphating of the plates is rapid. If your brand new battery is discharging from 12.7v to 11.7v in a week, you definitely have a leak and this could be down to one or more of the diodes in the voltage regulator failing. The alternator will tend to give out a high voltage long after it should have reduced, as it is pushing power into both the battery, and the leak, rather like pumping water into a tank with a hole in. When you switch off the supply, your briefly full battery continues to leak back through the diodes. When you leave your car after you have been for a drive, try disconnecting the wires from the alternator. If the battery remains fully charged, you have isolated the problem. If it continues to discharge, then it isn't the alternator!

More to the above post.--

The battery voltage is monitored by the voltage regulator in the alternator. It is set to give around 14 to 14.5 volts with a charged battery.

Think about switching on any of the cars electrical components. All of them could be considered as LEAKS.

However with all these things on and the engine at a fast tick-over the voltage will still read around 14 volts at the battery terminals even though lots of CURRENT is being used.---


Here endeth the sermon.-------