My battery reads 12.6 volts with nothing turned on. Same thing if I switch the battery switch off. If I turn on lights the voltage drops to the point that it read 12.2v with 8 lights on.
I know that those eight lights are drawing a fair amount of current, but what would explain the voltage drop as measured at the battery?
In theory, with sufficient current capacity the voltage at the source should remain constant.
Does that mean that the open circuit voltage is a false reading and that the true state of charge is indicated by the voltage when under load?
a battery will almost always read a higher un loaded voltage vs a loaded voltage... just normal battery life... the load will always draw some of the voltage down...
Every battery has a certain amount of internal resistance. You can think of your battery as being an ideal voltage source with a small (well under one ohm) resistor in series. As you draw current, the voltage drop across the internal resistance is what you are loosing.
Joel
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2011 Silverado 2500HD Duramax, 4x4, crew cab, long bed
Palomino Puma 253-FBS, 27' 5th wheel
1994 19' Class B on Chevy chassis
Linear Mode
