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Old 09-21-2019, 09:36 AM   #32
rotorwrench
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Join Date: Jun 2010
Location: San Antonio, Texas
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Default Re: 3 brush generator ????

Folks have mentioned what a fully charged battery may read. 2.125 volts per cell is max as a general rule but that is for a brand new battery with fresh lead plates and electrolyte. All batteries are just a bit different even of the same manufacturer and part number so there will be variations. After a battery is fully charged and it sets for a period of time, the voltage will drop off to around 6.1 volts on the average. 6.2 or 6.3 volts would be more likely while the battery is still being charged depending on age and condition of the battery. A bad battery will give a 3-brush system a real work out and can harm solid state parts like the fun projects regulator. A high discharge load test is the best test of any battery for condition. An electrolyte check can give a person an idea about what the state of charge is but it won't give an indication of the capacity that it's capable of.

The 3-brush generators were used for a long time due to the simplicity but they are not up to the task on the more modern systems with higher current draw. With radios and heaters being added, they just weren't cutting it any more. This is where the 2-brush finally came on line in 1939. It's field and armature design requires regulation of everything so it has voltage and current control as well as a cut out.

Last edited by rotorwrench; 09-21-2019 at 09:49 AM.
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