[Elecraft] Battery Charger Voltage High?

[Don Wilhelm]

  Wes,

Oh, I do understand the UC3906 charge controller.  Its bulk charge is a 
constant current source, which means the voltage is not controlled 
(except by the battery).  Once the voltage reaches the V12 point, it 
goes into an overvoltage charge until the current drops to a defined 
rate, then it goes to the float voltage.

The various voltages and current states are determined by the choice of 
resistors.  If the battery has high resistance and does not want to take 
a charge willingly, the charger will start out with the bulk charge and 
almost immediately switch to the overcharge voltage, and may never go to 
the float charge state.

So 16 volts is not an improbable situation, it all depends on the 
battery condition and the resistors chosen by the designer of the charger.

73,
Don W3FPR

On 5/27/2011 5:03 AM, Wes Stewart wrote:
>
> It's not unusual to do equalization charges on wet batteries at over 15V.  Bulk charging does NOT apply excessive voltages as one commentator cannot be made to understand. And the myths go on.....
>