|
Next revision
|
Previous revision
|
electrical:solar:gentle_complexity [2017/11/09 13:31]
frater_secessus created |
electrical:solar:gentle_complexity [2020/10/11 19:48] (current)
|
| ====== Gentle introduction, Pt 2 ====== | ====== Gentle introduction, Pt 2 ====== |
| |
| This is a collection of illustrations that things are more complex than can be revealed in a one-page intro. Again, drill down for more info. | This is a collection of illustrations that things are more complex than can be revealed in [[electrical:solar:gentle_intro|a one-page intro]]. Again, drill down for more info. |
| |
| | ----- |
| |
| **Solar panel output will almost never be as high as the claimed output.** In fact it will probably hover around 75% of that number under the best conditions; this is called "[[electrical:solar:output#panel_temperature|derating]]", or correcting output to actual conditions. It sounds like fraud but it's not. A panel's power is expressed as a "nominal" rating like 100W as when tested under //laboratory// conditions. Since the roof of your van is unlikely to meet those same lab conditions, if you think you need 200W of panel you probably need 250W. | **Solar panel output will almost never be as high as the claimed output.** In fact it will probably hover around 75% of that number under the best conditions; this is called "[[electrical:solar:output#panel_temperature|derating]]", or correcting output to actual conditions. It sounds like fraud but it's not. A panel's power is expressed as a "nominal" rating like 100W as when tested under //laboratory// conditions. Since the roof of your van is unlikely to meet those same lab conditions, if you think you need 200W of panel you probably need 250W. |
| **[[http://rvwiki.mousetrap.net/doku.php?id=electrical:12v:deep_cycle_battery#agm|AGM]] lead-acid batteries are not well suited to solar-only charging**. They cost about 2x that of FLA, have less capacity, require vigourous charging and cannot be charged as high in voltage. They remain popular because people think "$$$ is better" and are loathe to vent their banks. | **[[http://rvwiki.mousetrap.net/doku.php?id=electrical:12v:deep_cycle_battery#agm|AGM]] lead-acid batteries are not well suited to solar-only charging**. They cost about 2x that of FLA, have less capacity, require vigourous charging and cannot be charged as high in voltage. They remain popular because people think "$$$ is better" and are loathe to vent their banks. |
| |
| | It is possible (though uncommon) to have **one all-purpose battery for both house and starting**. This only works when [[electrical:solar:sizing#your_daily_power_needs|daily power requirements]] are quite low((40-50Ah/day)) or when [[electrical:solar:nonessential|opportunity loads]] are agressively utilized. There are two approaches to such a setup: |
| | - the premium battery deep-cycling approach as used by Sternwake((http://www.cheaprvliving.com/forums/Thread-Has-anyone-heard-of-Northstar-AGM-batteries?pid=135811#pid135811)) ((http://www.cheaprvliving.com/forums/Thread-SternWake-and-other-expert-advice-needed-on-electrical-hookup?pid=94943#pid94943)) This requires attention and knowledge. |
| | - the "make do" [[electrical:solar:shallow_cycling|shallow-cycling]] approach. This is more suitable for car dwellers and folks on limited resources. |
| |
| |
