Differences

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--- electrical:solar:status [2019/11/12 12:34]
frater_secessus [in absorption]
+++ electrical:solar:status [2020/08/29 22:32]
frater_secessus [when adding loads]
@@ Line 80: / Line 80: @@
-**During [[electrical:12v:charging#absorption#absorption_stage|Absorption]] charging with MPPT** the battery will need less and less current.
+**During [[electrical:12v:charging#absorption#absorption_stage|Absorption]] charging** lead-acid batteries will need less and less current.
+**with MPPT controllers**
   * Vpanel starts to creep up from Vmp toward Voc
   * Vbatt == Vabs until the controller's criteria for ending absorption is met
@@ Line 86: / Line 89: @@
   * **Example:**  Panel voltage 17v and rising, battery voltage held at Vabs == 14.6v, controller output amps 2A and dropping
-**During Absorption charging with PWM**
+**with PWM controllers**
   * Vpanel & Vbattery == Vabs until the controller's criteria for ending absorption is met
   * Controller output decreasing as current demand drops.
   * the controller may get warmer as current demand drops((percentage of time the PWM circuit is turned OFF increases))
   * **Example:**  Panel and battery voltage held at Vabs == 14.6v, controller output 2A and dropping
+==== transitioning to float ====
+When transitioning from Absorption to Float the voltage needs to drop about a volt.  The system will "free-fall" (make little or no power) to allow the voltage to fall.  The transition may take seconds or minutes, depending on how/if the system is loaded.
+  * starts at Vabs
+  * power generation stops
+  * voltage drops to Vfloat
+  * when voltage reaches Vfloat the system will start making power to hold that setpoint.
 ==== in float ====
 **During Float with MPPT**
-  * Vpanel close to Voc
+  * Vpanel closer to Voc
   * Vbattery == Vfloat
   * controller output minimal((assuming no loads))
@@ Line 120: / Line 133: @@
   * If enough power is available no change will be observed but the controller may run cooler((as PWM switching reduces in frequency.))
   * If demand outstrips supply the Vbattery & Vpanel will drop((causing a bit of a "death spiral", as PWM produces less power as panel voltage drops))
-  * **Example**:  Upon adding load, the controller releases power it had been dissipating in the PWM circuit.  Current output spikes to meet load demand.((this is reflected in either battery charging amps or load amps depending on how the loads are wired))  Output is limited to whatever power the panel puts out at Vabs & Vfloat.((almost certainly less than what the panel could put out at Vmp))
+  * **Example**:  Upon adding load, the controller releases power it had been constricting (modulating the pulse width). Current output spikes to meet load demand.((this is reflected in either battery charging amps or load amps depending on how the loads are wired))  Output is limited to whatever power the panel puts out at Vabs & Vfloat.((almost certainly less than what the panel could put out at Vmp))

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