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electrical:solar:shunt_tweaking [2020/01/14 15:14]
frater_secessus
electrical:solar:shunt_tweaking [2020/01/14 15:14]
frater_secessus
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 There are three [[electrical:solar:charge_controller_setpoints|setpoints]] that interest us:  charging setpoint, low voltage disconnect, and low voltage reconnect. There are three [[electrical:solar:charge_controller_setpoints|setpoints]] that interest us:  charging setpoint, low voltage disconnect, and low voltage reconnect.
  
-The charging setpoint, called PV OFF on the screen, is the highest voltage you want your battery to see.  There are no separate Absorption voltage (Vabs) or Float voltage (Vfloat) settings, just the one PV OFF setpoint.  So you have to pick a compromise.    There are a couple reasons to [[electrical:solar:pwm_tweaking#the_controller_s_achilles_heel|use a higher-than-usual voltage]]:  the battery will charge faster and the controller will be able to run the panels at a higher voltage where they make more power (closer to Vmp).  This means you can also run bigger loads without affecting the battery in addition to just charging faster.+The **charging setpoint**, called PV OFF on the screen, is the highest voltage you want your battery to see.  There are no separate Absorption voltage (Vabs) or Float voltage (Vfloat) settings, just the one PV OFF setpoint.  So you have to pick a compromise.    There are a couple reasons to [[electrical:solar:pwm_tweaking#the_controller_s_achilles_heel|use a higher-than-usual voltage]]:  the battery will charge faster and the controller will be able to run the panels at a higher voltage where they make more power (closer to Vmp).  This means you can also run bigger loads without affecting the battery in addition to just charging faster.
  
 So if you are deep cycling the batteries daily and can check water levels one can use something quite high like 14.7v((Trebor English reminds us to fiddle the voltage per season since these devices don't have temp compensation)) or as high as your battery manufacturer allows for Absorption.  Check your water levels!  If you are deep cycling but can't check water levels (maintenance free or AGM batts) Something like 14.2v.  If you are using the battery each night but not deeply, you might set it to a high float-like voltage like 13.8v.  If the batteries are just being maintained and not used consider dropping to a normal 13.2v float voltage. So if you are deep cycling the batteries daily and can check water levels one can use something quite high like 14.7v((Trebor English reminds us to fiddle the voltage per season since these devices don't have temp compensation)) or as high as your battery manufacturer allows for Absorption.  Check your water levels!  If you are deep cycling but can't check water levels (maintenance free or AGM batts) Something like 14.2v.  If you are using the battery each night but not deeply, you might set it to a high float-like voltage like 13.8v.  If the batteries are just being maintained and not used consider dropping to a normal 13.2v float voltage.
electrical/solar/shunt_tweaking.txt ยท Last modified: 2021/05/22 10:27 by frater_secessus