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electrical:12v:multipoint_charging

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electrical:12v:multipoint_charging [2018/08/26 10:03]
frater_secessus [why one source wins] 		electrical:12v:multipoint_charging [2020/05/11 17:47]
frater_secessus [concurrent charging]
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 ===== concurrent charging ===== ===== concurrent charging =====
  
-So what happens when multiple chargers are running at the same time?  Nothing dramatic, as it turns out.  +So what happens when multiple chargers are running at the same time?  Nothing dramatic, as it turns out.((The only caveat, for advanced users, is if one of your controller uses end-amps to signal the end of Absorption, it may [[http://forum.solar-electric.com/discussion/comment/389634#Comment_389634|get confused and drop out early]].))
  
-In general, **the charging source with the highest voltage will win**.  The only caveat is that if one of your controller uses end-amps to signal the end of Absorption, it may get confused and drop out early.((http://forum.solar-electric.com/discussion/comment/389634#Comment_389634))+In general, **the charging source with the highest voltage will win**.
  
 ==== why one source wins ==== ==== why one source wins ====
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 The alternator is just a plain alternator and puts out 14.0v all the time. The alternator is just a plain alternator and puts out 14.0v all the time.
 The Morningstar charge controller is factory set to start Absorption at 14.4v.((i.e. Vabs == 14.4v)) The Morningstar charge controller is factory set to start Absorption at 14.4v.((i.e. Vabs == 14.4v))
-The Xantrex charge controller has been configured by you to start Absorption at 14.7v.((i.e. Vabs == 14.7v))+The Xantrex charge controller has been configured by you to start Absorption at 14.7v.((i.e. Vabs == 14.7v)) ((Normally the controllers would be set to the same voltage but we will make them different to illustrate how it works.)) 
  
 Let's charge that battery.  Here is the battery voltage along the way: Let's charge that battery.  Here is the battery voltage along the way:
  
-  * **12.2v** at daybreak, approximately 50% [[electrical:depth_of_discharge|Depth of Discharge]].  Charging is in the Bulk stage and **all three sources are charging**; the battery bank voltage is lower than what they all want to provide.  The alternator is contributing the most because it can produce the most current. +  * **12.2v** at daybreak, approximately 50% [[electrical:depth_of_discharge|Depth of Discharge]].  Charging is in the Bulk stage and **all three sources are contributing**; the battery bank voltage is lower than what they all want to provide.  The alternator is contributing the most because it can produce the most current and the panels aren't getting much light yet.  
-  * **13.9v** a few miles down the road. Voltage is climbing but all three sources are still charging.+  * **13.9v** a few miles down the road. Voltage is climbing but all three sources are still charging.  The sun is higher in the sky so the panels are making more power now. 
   * **14.1v** by the you get to a neighboring town.  **Alternator charging ceased at 14.0v**; it has plenty of current but no voltage "pressure" to force that current into the battery.  Your battery bank is now being charging only by solar (the two separate controllers).   * **14.1v** by the you get to a neighboring town.  **Alternator charging ceased at 14.0v**; it has plenty of current but no voltage "pressure" to force that current into the battery.  Your battery bank is now being charging only by solar (the two separate controllers).
-  * **14.6v** in the parking lot as you stop at an Oasis [[:water|water kiosk]].  **The Morningstar stopped contributing at 14.4v**((Absorption is the stage where the controller provides as much current as it takes to hold Vabs, 14.4 in the Morningstar's case.  **It takes zero current to hold 14.4v when the bank is 14.6v**, so the Morningstar just sits there.  It might drop into Float.)) so we are down to just the Xantrex.  +  * **14.6v** in the parking lot as you stop at an Oasis [[water:drinking|water kiosk]].  **The Morningstar stopped contributing at 14.4v**((Absorption is the stage where the controller provides as much current as it takes to hold Vabs, 14.4 in the Morningstar's case.  **It takes zero current to hold 14.4v when the bank is 14.6v**, so the Morningstar just sits there.  It might drop into Float.)) so we are down to just the Xantrex.  
   * **14.7v** on your way back to camp.  This is Absorption setpoint (Vabs) of the Xantrex, the highest setpoint of all three.  The Xantrex will continue the Absorption stage by itself until that stage is complete, then drop back to Float voltage (Vfloat).((where the Morningstar has probably been waiting, twiddling its thumbs))   * **14.7v** on your way back to camp.  This is Absorption setpoint (Vabs) of the Xantrex, the highest setpoint of all three.  The Xantrex will continue the Absorption stage by itself until that stage is complete, then drop back to Float voltage (Vfloat).((where the Morningstar has probably been waiting, twiddling its thumbs))
  
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 So how do we make them all charge all the time? So how do we make them all charge all the time?
  
-Barring heroic measures((exotic alternators/regulators, DC-DC chargers)) the alternator is going to stop contributing at some point during Bulk charging.  That is ok, the alternator provided a ton of current while it was charging.+Barring heroic measures((exotic alternators/regulators, [[electrical:12v:b2b|DC-DC chargers]])) the alternator is going to stop contributing at some point during Bulk charging.  That is ok, the alternator provided a ton of current while it was charging.
  
 But if you want to the charge controllers (and some [[electrical:converter|converters]]) can be convinced to stay roughly in sync and keep charging together.  This is done by **configuring the Absorption and Float setpoints on the controllers to be the same**.((including Absorption termination setpoints like time or current))  There will be short periods where one controller makes a change before the other, but for most of the time both will be contributing at the same time. But if you want to the charge controllers (and some [[electrical:converter|converters]]) can be convinced to stay roughly in sync and keep charging together.  This is done by **configuring the Absorption and Float setpoints on the controllers to be the same**.((including Absorption termination setpoints like time or current))  There will be short periods where one controller makes a change before the other, but for most of the time both will be contributing at the same time.
electrical/12v/multipoint_charging.txt · Last modified: 2024/03/29 18:55 by frater_secessus

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