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electrical:12v:alternator

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electrical:12v:alternator [2024/04/05 11:10]
frater_secessus [gotchas] 		electrical:12v:alternator [2024/04/16 11:31]
frater_secessus [disabling alternator charging] delay
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   * they have **no way to limit current** other than hitting their max rating and failing or tripping.((diode-based isolators will reduce current somewhat due to forward-voltage losses))   This might mean the battery can pull more current than is good for itself or for the alternator, necessitating the use of [[electrical:12v:b2b|a DC-DC charger]].  This typically is an issue only with oversized banks or small alternators.    * they have **no way to limit current** other than hitting their max rating and failing or tripping.((diode-based isolators will reduce current somewhat due to forward-voltage losses))   This might mean the battery can pull more current than is good for itself or for the alternator, necessitating the use of [[electrical:12v:b2b|a DC-DC charger]].  This typically is an issue only with oversized banks or small alternators. 
   * they **can't boost voltage**((diode isolators will reduce voltage)) like DC-DC.  They are not "smart" and have no charging stages -- the house bank will be charged at alternator voltage while the engine is running. Compare your alternator's voltage output to the battery manufacturer's Absorption charging voltage [[electrical:solar:charge_controller_setpoints|setpoint]] before going this route.     * they **can't boost voltage**((diode isolators will reduce voltage)) like DC-DC.  They are not "smart" and have no charging stages -- the house bank will be charged at alternator voltage while the engine is running. Compare your alternator's voltage output to the battery manufacturer's Absorption charging voltage [[electrical:solar:charge_controller_setpoints|setpoint]] before going this route.  
-  * the charge acceptance rate (Amps) will decrease as bank voltage rises;  this is called the //current taper//.+  * the charge acceptance rate (Amps) will decrease as bank voltage rises;  this is called the //current taper//.  Because of the taper if you want to get maximal harvest for your engine's gasoline consumption it would be better to charge when the bank is low than if the bank is nearly full. 
   * vehicles with //smart// (variable voltage) alternators are usually not suitable for charging with normal combiners.((https://www.redarc.com.au/how-do-i-know-if-i-have-a-variable-voltage-smart-alternator))  See [[electrical:12v:alternator#smart_alternators|below]]   * vehicles with //smart// (variable voltage) alternators are usually not suitable for charging with normal combiners.((https://www.redarc.com.au/how-do-i-know-if-i-have-a-variable-voltage-smart-alternator))  See [[electrical:12v:alternator#smart_alternators|below]]
  
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 It may be desirable to disable alternator charging on-the-fly when stopped in traffic, on hot days, to avoid charging frozen Li cells,((using a temperature controller)) stop charging at a given voltage,((using a [[electrical:12v:alternator_charging_hvd|High Voltage Disconnect]])) or neutralize [[electrical:12v:alternator#gotchas|gotchas]], etc.  The method of disabling will vary depending on the gear: It may be desirable to disable alternator charging on-the-fly when stopped in traffic, on hot days, to avoid charging frozen Li cells,((using a temperature controller)) stop charging at a given voltage,((using a [[electrical:12v:alternator_charging_hvd|High Voltage Disconnect]])) or neutralize [[electrical:12v:alternator#gotchas|gotchas]], etc.  The method of disabling will vary depending on the gear:
  
-  * relays and DC-DC that are triggered solely by D+ can be disabled by a switch on the D+ wire+  * relays and DC-DC that are triggered solely by D+ can be disabled by a switch on the D+ wire.  [[https://www.reddit.com/r/VanLife/comments/1c4vjl0/is_this_renogy_a_good_dcdc_option_for_a_200ah/kzuc78v/|Additional control could be introduced]] with a relay and or delay ([[https://amzn.to/3TUEbmu|example]])
   * VSR triggered by voltage can can be disabled by a switch on the thin ground wire on the VSR itself.((the VSR requires a ground to make a complete circuit to run internal electronics.  Breaking this circuit turns off the  VSR))     * VSR triggered by voltage can can be disabled by a switch on the thin ground wire on the VSR itself.((the VSR requires a ground to make a complete circuit to run internal electronics.  Breaking this circuit turns off the  VSR))  
   * some DC-DC can be //derated// by providing a 12v signal to the CURRENT LIMIT terminal ([[electrical:12v:b2b#renogy1|Renogy DC1212 series]], [[electrical:12v:b2b#leaptrend|Leaptrend]])   * some DC-DC can be //derated// by providing a 12v signal to the CURRENT LIMIT terminal ([[electrical:12v:b2b#renogy1|Renogy DC1212 series]], [[electrical:12v:b2b#leaptrend|Leaptrend]])
electrical/12v/alternator.txt ยท Last modified: 2024/04/26 17:11 by frater_secessus

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