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electrical:12v:alternator [2020/05/21 10:45]
frater_secessus [Alternator charging]
electrical:12v:alternator [2020/06/23 11:58]
frater_secessus [isolators]
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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. 
 + 
 + 
 +==== manual switch ==== 
 + 
 +[[https://amzn.to/2VaL8SG|{{https://m.media-amazon.com/images/I/81n-ap+0lPL._AC_UY218_.jpg }}]]The simplest and least-featured isolator is a //manual switch//. 
 + 
 +Pro:  very little to go wrong. 
 + 
 +Con:  must be operated manually and one must remember to do so. Leaving the switch in the combined position when not driving will drain both the house and 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))
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 Note that you will only have to run the POS+ leg of wire to the house battery as the chassis ground is the other leg. Note that you will only have to run the POS+ leg of wire to the house battery as the chassis ground is the other leg.
  
-==== alternator hacks ===+===== alternator hacks =====
  
 There are ways to get the alternator to pump out more power: There are ways to get the alternator to pump out more power:
electrical/12v/alternator.txt · Last modified: 2024/03/15 12:27 by frater_secessus