I need some help in understanding basic battery charging. I read about the three common stages: Bulk Charging, Absorption Stage and Float Stage, but I can't understand exactly what the controller does in the first two.
Let me explain my problem:
During the Bulk phase of the charge cycle, the voltage gradually rises to the Bulk level (usually 14.4v volts) while the batteries draw maximum current. When Bulk level voltage is reached the absorption stage begins"
Does it mean that the controller voltage is gradually rising so it always will be above battery voltage, while the battery voltage is rising due to the current from difference on voltage (controller-battery)?
Can the current to the battery can be calculated by Ohm's law: (Vcontroller-Vbattery)/Battery Resistance?
"During this phase the voltage is maintained at Bulk voltage level for a specified time (usually an hour) while the current gradually tapers off as the batteries charge up"
The controller voltage is constant, or the battery voltage is kept constant? If it is the battery voltage, how can you keep constant voltage of a battery, if flow of current is into the battery, that means increasing voltage...
Why does the current decrease with time if the Battery Voltage is being set constant? Does the resistance of the battery increase when it's more charged?
Sorry for the damn questions, but I have some holes in my education... Thanks in advance.