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electrical:solar:car [2023/09/21 10:25]
frater_secessus [$110] 		electrical:solar:car [2024/01/04 12:56]
frater_secessus [performance]
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 ====== example setups ====== ====== example setups ======
 +
 +The following DIY setups sketch out what off-grid power systems for cardwellers might look like.  These are ideas to compare against your own use case and [[electrical:12v:dailypowerrequirements|specific power requirements]], not recipes to follow. **Read the specs** on each piece of gear before purchase. 
 +
 +===== general principles =====
 +
 +The [[electrical:12v:alternator|alternator]] is the most powerful charging source available in the vehicle.  The amount of power you can safely take from it [[electrical:12v:alternator_details#current|depends on the alternator's current rating]].  The alternator can charge the battery bank through [[electrical:12v:alternator#combiners|a relay]] (crudely, cheaply) or [[electrical:12v:b2b|DC-DC charger]] (precisely, expensively).
 +
 +100w **solar panels** are ~$1/watt.  Used higher voltage panels are about 1/3rd of the price per watt, but require [[electrical:solar:charge_controller#mppt|an MPPT solar charge controller]] and are typically >200w.  
 +
 +Larger battery banks don't just store more energy, they allow higher charging rates from the alternator((or solar, but most cars don't have enough room for that much solar)) without stressing the battery)).  
  
 ===== $800 ===== ===== $800 =====
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 This is a relatively large setup for a cardweller, but at this point we get to leverage the economies of larger batteries and used panels.   This is a relatively large setup for a cardweller, but at this point we get to leverage the economies of larger batteries and used panels.  
  
-  * 200w [[electrical:solar:panels#panel_voltage|higher-voltage]] used panel, mounted between luggage rails, ~$75+  * 250w [[electrical:solar:panels#panel_voltage|higher-voltage]] used panel, mounted between luggage rails, ~$80
   * [[electrical:12v:b2b#kisae|kisae DMT1230]] 30A MPPT+DC-DC, $225   * [[electrical:12v:b2b#kisae|kisae DMT1230]] 30A MPPT+DC-DC, $225
   * [[https://amzn.to/3EyQhKG|100Ah self-heated LiTime LiFePO4]] (or similar), $440   * [[https://amzn.to/3EyQhKG|100Ah self-heated LiTime LiFePO4]] (or similar), $440
   * small PSW inverter like [[https://amzn.to/48aWp9u|the Bestek 300w]], up to 500w would be comfortable for the battery.   * small PSW inverter like [[https://amzn.to/48aWp9u|the Bestek 300w]], up to 500w would be comfortable for the battery.
 +
 +Dropping to 50A LFP would decrease cost to ~$510. All numbers below would stay the ~same.((alternator should be limited to 25A charging, so 166Wh instead of 200Wh harvested))
  
 Actual power harvest would vary depending on the amount of driving (alternator), and [[electrical:solar:pvwatts|location/season]] (solar).  Let's assume 30 minutes of driving each day and middling latitudes like Salt Lake City.  Actual power harvest would vary depending on the amount of driving (alternator), and [[electrical:solar:pvwatts|location/season]] (solar).  Let's assume 30 minutes of driving each day and middling latitudes like Salt Lake City. 
  
-  * summer (June) - ~200Wh alternator + 1,186Wh solar = **1,387Wh/day** (1.73Wh/$) + 
-  * winter (December) - ~200Wh alternator + 335Wh solar = **535Wh/day**+==== performance ==== 
 + 
 +Solar, conditions described above 
 + 
 +  * summer (June) - ~200Wh alternator + 1,483Wh solar = **1,683Wh/day** (2.10Wh/$) 
 +  * winter (December) - ~200Wh alternator + 401Wh solar = **602Wh/day** 
 + 
 +loads 
 + 
 +  * DC ~50A (650w)((solar might provided another 213w under optimal conditions, allowing loads up to 663w without exceeding LFP's typical 0.5C sustained discharge spec)) 
 +  * AC (inverter) ~40A (520w)
  
 ===== $650 ===== ===== $650 =====
  
-As above, replacing the DC-DC/MPPT combo with separate relay/VSR and 20A MPPT. Solar harvest stays the same, but I'll estimate average alternator harvest [[https://rvwiki.mousetrap.net/doku.php?id=electrical:12v:directcharginglfp#comparison|drops by half]].  +As above, replacing the DC-DC/MPPT combo with separate relay/VSR and 20A MPPT. Solar harvest stays the same, but I'll estimate average alternator harvest [[https://rvwiki.mousetrap.net/doku.php?id=electrical:12v:directcharginglfp#comparison|drops by almost half]] at normal states of charge.   
  
  
-  * summer (June) - ~100Wh alternator + 1,186Wh solar = **1,287Wh/day** (1.98Wh/$) +  * summer (June) - ~130Wh alternator + 1,483Wh solar = **1,613Wh/day** (2.03Wh/$) 
-  * winter (December) - ~100Wh alternator + 335Wh solar = **435Wh/day**+  * winter (December) - ~130Wh alternator + 401Wh solar = **531Wh/day**
  
-===== $410 ===== 
  
-Simplifying with PWM controllers and relays instead of DC-DC.  +===== $480 =====
  
-  * 50A LiFePO4+Simplifying with PWM controllers and relays instead of DC-DC.  1/2 the battery, so ~1/2 the alternator charging.  Price doesn't go down much because we are paying $1/watt retail for new panel.   
 + 
 +  * 50A LiFePO4, $160
   * combiner or VSR for alternator charging - $50   * combiner or VSR for alternator charging - $50
   * 2x 100w panel - $200   * 2x 100w panel - $200
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   * small PSW inverter like [[https://amzn.to/48aWp9u|the Bestek 300w]] - $60     * small PSW inverter like [[https://amzn.to/48aWp9u|the Bestek 300w]] - $60  
  
-Same assumptions as the above 
  
-  * summer (June) - ~108Wh alternator + 488Wh solar = **1,084Wh/day** (2.61Wh/$) +==== performance ====
-  * winter (December) - ~108Wh alternator + 284Wh solar = **392Wh/day**+
  
 +Solar, same assumptions as the above
  
  
 +  * summer (June) - ~65Wh alternator + 488Wh solar = **1,041Wh/day** (2.54Wh/$)
 +  * winter (December) - ~65Wh alternator + 284Wh solar = **349Wh/day**
 +
 +loads
 +
 +  * DC ~25A (325w)
 +  * AC (inverted) ~20A (260w)
 ===== $300 ===== ===== $300 =====
  
 Half the solar brings the cost (and harvest) down: Half the solar brings the cost (and harvest) down:
  
-  * 50A LiFePO4+  * 50A (640Wh) LiFePO4
   * combiner or VSR for alternator charging - $50   * combiner or VSR for alternator charging - $50
   * 100w panel - $100   * 100w panel - $100
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   * small PSW inverter like [[https://amzn.to/48aWp9u|the Bestek 300w]] - $60     * small PSW inverter like [[https://amzn.to/48aWp9u|the Bestek 300w]] - $60  
  
-Same assumptions as the above+==== performance ====
  
-  * summer (June) - ~108Wh alternator + 488Wh solar = **596Wh/day** (1.99Wh/$) 
-  * winter (December) - ~108Wh alternator + 142Wh solar = **250Wh/day** 
  
 +Solar, Same assumptions as the above
  
 +  * summer (June) - ~65Wh alternator + 488Wh solar = **553Wh/day** (1.84Wh/$)
 +  * winter (December) - ~65Wh alternator + 142Wh solar = **207Wh/day**
 +
 +loads
 +
 +  * DC ~25A (325w)
 +  * AC (inverted) ~20A (260w)
 ===== $110 ===== ===== $110 =====
  
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   * 10A single stage PWM charger - $15   * 10A single stage PWM charger - $15
  
 +==== performance ====
  
-Same assumptions as the above+Solar, same assumptions as the above
  
   * summer (June) - 488Wh solar = **488Wh/day** (4.44Wh/$)   * summer (June) - 488Wh solar = **488Wh/day** (4.44Wh/$)
   * winter (December) - 142Wh solar = **142Wh/day**   * winter (December) - 142Wh solar = **142Wh/day**
  
 +loads
 +
 +  * DC ~10A (130w)
 +  * no AC (inverter) loads
  
electrical/solar/car.txt · Last modified: 2024/01/04 12:56 by frater_secessus

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