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--- electrical:solar:synopsis_puzzle2 [2017/07/31 21:06]
frater_secessus [Synopsis: HandyBob's RV Battery Charging Puzzle 2]
+++ electrical:solar:synopsis_puzzle2 [2020/10/11 23:48] (current)
@@ Line 1: / Line 1: @@
+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 ======
+[Note from Secessus:  I do my best here to faithfuly summarize //Bob's// point of view and not editorialize or take issue with it.]
 HandyBob and his wife are fulltimers in a 5th wheel and have no generator.  He prefers quiet and and wants folks to stop using generators, or at least use them more considerately.
@@ Line 65: / Line 64: @@
 ===== converters =====
-Most OEM [[electrical:converter|converters]] are bad, functioning like trickle chargers.  Even the smart ones charge at too low a voltage and commence float too early.  They may get confused by [[electrical:12v:multipoint_charging|multipoint charging]].
+Most OEM [[electrical:converter|converters]] are bad, functioning like trickle chargers.  Even the smart ones charge at too low a voltage and commence float too early.  They may get confused by multipoint charging.
+===== generators =====
+A generator with DC battery charging output is better than running the converter or auto charger on 110v.
+===== solar =====
+Bob runs his RV off 345W of panel and 450AH of 6v deep cycle batteries.
+> "Adding solar panels to an under wired system is like putting a big motor in a little car with a tiny drive train & skinny tires.  You can’t use the power."  -- HandyBob
+When seeking advice:
+> "Don’t ask the guy with solar panels and a generator running behind his rig on a sunny day."  -- HandyBob
+"Professional" installers may not be any good.
+===== 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.

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