Alternator Charging

hoss

Junior Member
I have a 1930 Model A Coupe with the original tail light and I have added turning lights with a third light in the back window. I also have sealed beam headlights. I have a 6 volt, 30 amp alternator for the system. Everything seems so function properly with one exception: The alternator does not recharge the battery. I have a new battery (3 days old) and as I drive the car the ammeter shows a charge with the high, or low, sealed beams on, horn working, turning signal working and the brake lights (with third light) working but they seem to be working off the battery because when I get home and put my battery charger on it, it registers 25% charged. I recharge the battery and drive it again and get the same results, the battery has ony 25% charge. I would certainly appreciate any helpful information concerning this problem. I thank any, or all, responders in advance.

Hoss in Missouri
 
Hoss, when you return home, what does the starter sound like when you leave the ign switch off and crank the engine? Compare this to the sound of the starter when the battery is fully charged and compare. It may be the batter is indeed charged but the battery charger is what is inaccurate.
 
The only thing I use the guage on a battery charger for is to verify I have a good connection when charging.I wiggle the clamps until the needle goes up.Does it turn over good,or do you have to charge it to start it again?At 25% it should barely turn over.Also,is that 25% reading assuming 12 volts or 6? Do you have reason the believe you have a problem,or you trying to be thorough and overthinking the situation?
 
Start the car and shine your headlights on the garage door or wall at night. Leave the lights on, but turn the engine off. Did the light dim slightly? If it did your charging system is working.

In the daytime you can use a volt meter and see if the voltage at the battery drops slightly as the engine is turned off. If it did, then the charging system is working.
 
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