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electrical:solar:sizing [2020/01/19 19:44]
frater_secessus [your reserve needs] 		electrical:solar:sizing [2021/06/21 14:06]
frater_secessus [usable capacity in Amp-hours]
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   - worst case scenario [[electrical:12v:loads|loads]] (the max loads you will apply in any 24hr period((or at any given time, if you plan to run heavy loads)))   - worst case scenario [[electrical:12v:loads|loads]] (the max loads you will apply in any 24hr period((or at any given time, if you plan to run heavy loads)))
-  - worst case scenario sunlight, usually December in your geographical area due to shortest daylight hours, but also affected by tree canopies, mountains, "urban canyons", or other forms of [[electrical:solar:electrical:solar:output#shadeelectrical:solar:output#shade|shading]]+  - worst case scenario sunlight, usually December in your geographical area due to shortest daylight hours, but also affected by tree canopies, mountains, "urban canyons", or other forms of [[electrical:solar:shading|shading]]
   - days of reserve (ie with no solar charging) you want   - days of reserve (ie with no solar charging) you want
   - whether or not you have access to other forms of charging: [[electrical:shore_power|shore power]], [[electrical:12v:alternator|alternator]], [[electrical:generator|generator]]   - whether or not you have access to other forms of charging: [[electrical:shore_power|shore power]], [[electrical:12v:alternator|alternator]], [[electrical:generator|generator]]
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   * [[http://gpelectric.com/tools/GoPowerCalculator.htm?state=RvDiv|GoPower calculator]]   * [[http://gpelectric.com/tools/GoPowerCalculator.htm?state=RvDiv|GoPower calculator]]
   * [[http://www.rvsolarsystemsonline.com/wattage-calculator/|RVSSO calculator]]   * [[http://www.rvsolarsystemsonline.com/wattage-calculator/|RVSSO calculator]]
 +
 +Also see [[https://re.jrc.ec.europa.eu/pvg_tools/en/tools.html#SA|the EU PVGIS modeler]].
  
 ===== your reserve needs ===== ===== your reserve needs =====
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 A rule of thumb is flooded lead acid batteries in offgrid scenarios should be charged between C/10 and C/8.  For a 200AH bank this would be 20A-25A.  Charging at lesser rates may result in not getting fully charged each day.  Charging at greater rates may result in increased outgassing and the need for a lengthier Absorption stage. A rule of thumb is flooded lead acid batteries in offgrid scenarios should be charged between C/10 and C/8.  For a 200AH bank this would be 20A-25A.  Charging at lesser rates may result in not getting fully charged each day.  Charging at greater rates may result in increased outgassing and the need for a lengthier Absorption stage.
 +
 +==== charging efficiency ====
 +
 +Lead batteries take something like ~13% more amps to charge from 50% DoD than were consumed.  So if you need to replace 50A it will take ~56.5A the next day to replace it.  //While// you are running your normal loads.
  
  
 +Lithium batteries have very high charging efficiency, so 50A consumed will take ~50A to recharge.  
  
 ==== voltage ==== ==== voltage ====
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     * deep cycling with [[electrical:solar:sizing#augmenting_solar|augmented charging]] in the morning     * deep cycling with [[electrical:solar:sizing#augmenting_solar|augmented charging]] in the morning
   * **2:1** - deep cycling and charging from solar only   * **2:1** - deep cycling and charging from solar only
-  * **3:1** - deep cycling and charging from solar only in areas with low insolation like the Pacific Northwest (PNW)+  * **3:1** - deep cycling and charging from solar only in [[opinion:frater_secessus:panelsizesforinsolation|areas with low insolation]] like the Pacific Northwest (PNW)
  
 A **crude rule of thumb for panel output per day** is a horizontally mounted panel on a sunny day will generate Ah (amp hours) roughly equal to Rated Wattage / 3.((http://www.cruisersforum.com/forums/f14/current-strategies-in-solar-power-42602.html#post473854)) \\  A **crude rule of thumb for panel output per day** is a horizontally mounted panel on a sunny day will generate Ah (amp hours) roughly equal to Rated Wattage / 3.((http://www.cruisersforum.com/forums/f14/current-strategies-in-solar-power-42602.html#post473854)) \\ 
electrical/solar/sizing.txt ยท Last modified: 2023/08/31 19:54 by princess_fluffypants

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