What Is The Voltage Of A Good Alternator

A good alternator should put out between 135-145 volts.

What is the voltage of a good alternator. The alternator should be tested with the engine idling and electrical accessories such as the radio and headlights turned off. If the alternator is putting out too much voltage 15 volts it is likely your battery acid will boil over out of the battery. If the battery is showing more then 126 the alternator is involved and charging.

If the reading stays the same or drops that means the alternator isnt charging and you may need a new one. The voltage should increase by between 05 and 2 volts to around 136 to 158. I ended up getting a high output alternator on eBay the voltage now only drops down to 134 volts under those same conditions which seems good to me since under a worst case scenario it is still charging the battery rather than draining it.

If these test are good then i believe the charging system is doing its job. If the voltage dips below the optimal range then the regulator kicks in to get the alternator to make more voltage. However if its not up into the 13 or 14 volt range it usually means the alternator is weak.

A good alternator should put out between 135-145 volts. The voltage should read a minimum of 13 volts. If you do replace or rebuild your alternator its good insurance to change the belt out with a high quality replacement.

So if we use a diode at low current it will drop just about the right voltage. The purpose of this test is to assess the controlled output of the alternator in relation to electrical load on the battery. Stress test the alternator Place a load on the alternator by turning on the headlights the radio and the air conditioning.

Stress test the alternator - Place a load on the alternator by turning on the headlights the radio and the air conditioning. Charging amperage will rapidly decrease and charging voltage will rapidly increase on a badly sulfated battery. A good alternator should put out between 135-145 voltsStress test the alternator Place a load on the alternator by turning on the headlights the radio and the air conditioning.