If the battery is very low on charge, the charging voltage at fast idle should be about 6.5 to 6.8 volts. As the battery charges up, the current flow should decrease (ammeter closer to center) and the voltage should go up. With a fully-charged battery, the charge current should be 5 to 8 amps, and the voltage should be around 7.2 to 7.5 volts volts.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!