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electrical:12v:alternator

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electrical:12v:alternator [2020/04/11 11:39]
frater_secessus [voltage-sensing relays]
electrical:12v:alternator [2020/05/24 12:08]
frater_secessus [wiring]
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 ====== Alternator charging ====== ====== Alternator charging ======
 +
 +aka Split Charging for our European friends
  
 In a dual-battery system((starter battery and house battery)) some of the alternator output is used to charge the house batteries when the engine is running.  When the engine is not running **the house battery is electrically isolated** from the starter battery to keep from draining it and leaving you stranded.  So the devices that handle the isolating/combining duties are called //battery isolators// There are several different types.  In a dual-battery system((starter battery and house battery)) some of the alternator output is used to charge the house batteries when the engine is running.  When the engine is not running **the house battery is electrically isolated** from the starter battery to keep from draining it and leaving you stranded.  So the devices that handle the isolating/combining duties are called //battery isolators// There are several different types. 
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-Power from the alternator is shared with the house battery using an isolator of some sort.  This allows the [[electrical:12v:intro|house battery]] to charge but does not allow the house battery to pull power from the starter battery.+Power from the alternator is shared with the house battery using an isolator ("Split charge relay" / SCR) of some sort.  This allows the [[electrical:12v:intro|house battery]] to charge but does not allow the house battery to pull power from the starter battery.
  
 ==== constant-duty solenoid ==== ==== constant-duty solenoid ====
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 ===== gotchas ===== ===== gotchas =====
  
-Alternator charging may bring some battery chemistries (like lithium) to unsuitably high voltages.   A [[electrical:12v:hvd|high voltage disconnect]] can [[electrical:12v:alternator charging hvd|restrict alternator charging to lower voltages]].+Alternator charging may bring some battery chemistries (like lithium) to **unsuitably high voltages**.   A [[electrical:12v:hvd|high voltage disconnect]] can [[electrical:12v:alternator charging hvd|restrict alternator charging to lower voltages]].  [[electrical:12v:b2b|DC-DC chargers]] can also regulate voltage provided to the house battery.  
 + 
 +**Idling the engine** to charge house batteries **can seriously overheat the alternator**.  It is usually cooled by wind from the vehicle's forward motion;  a fan may help cool the alternator.
  
-Idling the engine to run the alternator can seriously overheat the alternator.  It is usually cooled by wind from the vehicle's forward motion;  fan may help cool the alternator.+In early morning when house battery voltage is lowest, **a plain solenoid may unintentionally allow depleted batteries to pull down the starter battery**.  Workarounds:  use VSR, or start the vehicle immediately after inserting the key((ie, do not leave in the Accessory position which would drain the starter battery)) 
  
-==== wiring ====+===== wiring =====
  
 2 gauge copper wire connecting the coach and house is recommended for most alternator charging installs.  SternWake recommends attaching at the alternator rather than the battery.((http://www.cheaprvliving.com/forums/Thread-Charge-house-batteries-with-DC?pid=110652#pid110652)) 2 gauge copper wire connecting the coach and house is recommended for most alternator charging installs.  SternWake recommends attaching at the alternator rather than the battery.((http://www.cheaprvliving.com/forums/Thread-Charge-house-batteries-with-DC?pid=110652#pid110652))
electrical/12v/alternator.txt · Last modified: 2024/03/15 12:27 by frater_secessus