Re: Battery Charging Question

Posted by gone1951 On 2010/2/3 19:52:21

Quote:

Yes, Just measure the terminal voltage at the battery. With the engine shut off the battery, with the surface charge drained, will read pretty much 6.3 volts. The fact that 3 lead acid cells puts out 6.3 volts is why the filiment voltage for all 6 volt vacuum tubes was designed for this(6.3 volt) voltage. With the engine running at say 1500 RPM+ it should read between say 7 and 7.4 volts. If the Battery terminal voltage is much above the 7.4 volts it's too high. If you hook the meter to the battery and note the voltage then start the car and run it up the battery voltage should slowly climb up to as much as 7.4 volts. Any rise of .5 or more means the battery is charging.