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rv:idling [2022/07/26 13:03]
frater_secessus reordered
rv:idling [2023/10/01 19:29] (current)
frater_secessus [harm reduction]
Line 3: Line 3:
 ===== charging ===== ===== charging =====
  
-In addition to the problems listed above, idling to charge is [[electrical:12v:alternator#effect_on_alternator|hard on the alternator]].  +Idling to charge is [[electrical:12v:alternator#effect_on_alternator|hard on the alternator]].  
  
-Alternators are typically only ~50% efficient.  When the alt is pumping out 500w for your use **it is also creating 500w of heat**, cooking itself.  The easiest way to avoid excess alternator heat is only charge from the alternator while driving. This has two effects:+Alternators are typically only ~50% efficient.  When the alt is pumping out 500w for your use **it is also creating 500w of heat**, cooking itself.  The easiest way to avoid excess alternator heat is only charge from the alternator while driving (engine rpm ~2,000). This has multiple effects:
  
   - the alternator spins fast enough that its own cooling blades become effective, and    - the alternator spins fast enough that its own cooling blades become effective, and 
-  - airflow from the forward motion of the vehicle blows away heat+  - the alternator is running at its most efficient RPM((~6,000)) 
 +  - airflow from the forward motion of the vehicle helps remove heat from underhood
  
  
 +==== harm reduction ====
 +
 +Assuming people are going to do it anyhow, here are some steps to reduce changes of a Bad Outcome:
 +
 +  * open the hood to allow excess underhood heat to escape.  Sun should not shine directly into the engine bay.
 +  * point the vehicle's grille into any breeze, if present
 +  * watch for red flags
 +    * hot smells
 +    * belt squealing
 +    * engine RPM dropping significantly
 +    * chassis voltage falling from normal levels (14.1v, or whatever you observe without charging)
 +    * charger reporting less current than usual, if applicable
  
 ===== heating and cooling ===== ===== heating and cooling =====
rv/idling.1658855032.txt.gz · Last modified: 2022/07/26 13:03 by frater_secessus