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electrical:solar:synopsis_puzzle2 [2017/08/01 18:10]
frater_secessus [converters]
electrical:solar:synopsis_puzzle2 [2017/08/03 22:10]
frater_secessus
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 +This page aims to distill the knowledge contained in HandyBob's [[https://handybobsolar.wordpress.com/the-rv-battery-charging-puzzle-2/|RV battery charging puzzle 2]] page. 
  
 +Particularly useful and pithy statements are quoted directly under fair use.
  
-This page aims to distill the knowledge contained in HandyBob's [[https://handybobsolar.wordpress.com/the-rv-battery-charging-puzzle-2/|RV battery charging puzzle 2]] page. 
- 
-Particularly useful and pithy statements are quoted directly. 
  
 ====== Synopsis: HandyBob's RV Battery Charging Puzzle ====== ====== Synopsis: HandyBob's RV Battery Charging Puzzle ======
Line 84: Line 83:
 "Professional" installers may not be any good.  "Professional" installers may not be any good. 
  
-On sizing:   
  
-> "If you want to just be able to run your lights, water pump, charge the cell phone and run the occasional small kitchen appliance, acting more like a camper than a full timer, you only need one panel and one or two batteries.  If you want to run the TV a bit, computer, the microwave to warm up soup or make popcorn and some kitchen appliances you’ll need two panels and four batteries.  Of course you need more panels if you go where the sun doesn’t shine or if want to run more, such as unusual loads like a freezer in the basement or a CPAP machine to keep you breathing all night." -- HandyBob+===== charge controllers =====
  
 +Get an oversized [[electrical:solar:charge_controller|3-stage charge controller]] with an equalization function.
 +
 +Bob prefers Morningstar.
 +
 +===== MPPT boost controllers =====
 +
 +They work but the gains are found in specific scenarios like deeply discharged batteries.  The gains are more likely to be 5%-10% over PWM.
 +
 +
 +===== wiring =====
 +
 +"Big wire" is cheaper than panels for a similar gain in power.
 +
 +Wiring from panels to controller is important;  wiring from the controller to batteries is critical.
 +
 +Use stranded wire, the type (building, automotive, welding) is less important.  Use UV-shielded wire for external runs.
 +
 +> "big wire is there to limit voltage drop, not to carry amps." -- HandyBob
 +
 +
 +===== inverters =====
 +
 +Use a properly sized [[electrical:inverter|inverter]] for the job;  this may mean owning more than one inverter.
 +
 +MSW is fine unless you know you have something that needs PSW:  "residential refrigerators, washing machines, some air purifiers, some desk top computers and Craftsman brand battery chargers."
 +
 +"Soft start" inverters work work well.
 +
 +Many inverters have a high voltage disconnect (Vhvd) of 15v.  Temperature compensated charge controllers can hit 15v easily.
 +
 +===== installation considerations =====
 +
 +Install the charge controller near the batteries.
 +
 +Locate solar panels so they are not shaded.
 +
 +===== fusing =====
 +
 +Bob prefers fuses to automotive-style circuit breakers.
 +
 +Avoid fuse holders with springs in them.
 +
 +Fuse every positive wire within a few inches of the battery.
  
-===== charge controllers ===== 
  
  
electrical/solar/synopsis_puzzle2.txt · Last modified: 2020/10/11 19:48 (external edit)