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opinion:frater_secessus:beginner_mistakes [2022/03/31 12:43] frater_secessus [Too much panel] |
opinion:frater_secessus:beginner_mistakes [2022/06/06 11:50] frater_secessus [Failure to ask good questions] |
* picky eaters | * picky eaters |
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| Further reading: [[https://cheaprvliving.com/do-you-have-what-it-takes-to-live-in-a-vehicle/|Do You Have What It Takes to Live in a Vehicle?]], particular the section about it being 90% //self// and 10% //stuff//. |
===== Planning ===== | ===== Planning ===== |
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Having no solar at all is generally an unforced error for vandwellers. Even [[electrical:12v:alt_and_solar|adding small amounts of panel]] (100w) can make a big difference, and can be added to an [[electrical:12v:alternator|alternator-charged system]] for as little as $100.((100w poly panel on sale for $90, 10A [[electrical:solar:shunt_tweaking|shunt controller]] for $10.)) | Having no solar at all is generally an unforced error for vandwellers. Even [[electrical:12v:alt_and_solar|adding small amounts of panel]] (100w) can make a big difference, and can be added to an [[electrical:12v:alternator|alternator-charged system]] for as little as $100.((100w poly panel on sale for $90, 10A [[electrical:solar:shunt_tweaking|shunt controller]] for $10.)) |
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| ==== believing 100w of panel will make 100w all day long ==== |
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| The 100w panel will make 100w in a lab in test conditions. Your van is not in a lab in test conditions. |
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| - the panel will rarely make anywhere close to 100w((under normal conditions)) |
| - the max power it //does// make will be around local solar noon. Before and after that power will be less. |
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| Example: Albuquerque, NM on May 15, 2022.((assuming clear skies, no shade, MPPT, total system efficiency 85%)) |
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| ^ Time ^ Watts ^ |
| |6:02a |0w| |
| |7:02a |15.9w| |
| |8:02A |32.8w| |
| |9:02A |48.7w| |
| |10:02A |62.3w| |
| |11:02A |72.8w| |
| |12:02A |79.39w| |
| |**1:02p** - local solar noon |81.7w| |
| |2:02 |79.5w| |
| |3:02p |72.9w| |
| |4:02p |62.5w| |
| |5:02p |48.9w| |
| |6:02p |33.1w| |
| |7:02p |16.2w| |
| |8:02p |0w| |
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| See the //not enough panel// section below. |
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| ==== shade ==== |
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| Shade will wreck solar harvest. Beginners often don't pay attention to shade conditions, including shade thrown by objects on the van roof itself. |
==== Worrying ==== | ==== Worrying ==== |
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Don't get me started on people **flat-mounting poly/mono flex panels to the roof of their van**. Maximum cost, maximum power loss due to temp derating, //and// with the bonus of blasting re-radiated heat right through the van roof. It's a crap trifecta. | Don't get me started on people **flat-mounting poly/mono flex panels to the roof of their van**. Maximum cost, maximum power loss due to temp derating, //and// with the bonus of blasting re-radiated heat right through the van roof. It's a crap trifecta. |
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| === mixing different panels === |
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| Mixing differently-rated panels will always be sub-optimal. People who know what they are doing can minimize the losses. Beginners should either buy identical panels or run different types on separate controllers. |
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=== Panel types and controllers === | === Panel types and controllers === |
Understand that **efficiency is a relationship between rated output and physical panel size**: a high-efficiency 100w panel will not make more power than a low-efficiency 100w panel. It //will// be smaller. | Understand that **efficiency is a relationship between rated output and physical panel size**: a high-efficiency 100w panel will not make more power than a low-efficiency 100w panel. It //will// be smaller. |
This means **if you have limited space you will get more power out of of the same space using higher-efficiency panels**. That's it. A 100w panel is a 100w panel, no matter how efficient. Only the real estate needed to generate that 100w is different. Efficiency doesn't mean you'll get more or less power from a 100w panel. So don't spend the extra $$$ on high-efficiency panels unless you need it to get max power out of limited roofspace. | This means **if you have limited space you will get more power out of of the same space using higher-efficiency panels**. That's it. A 100w panel is a 100w panel, no matter how efficient. Only the real estate needed to generate that 100w is different. Efficiency doesn't mean you'll get more or less power from a 100w panel. So don't spend the extra $$$ on high-efficiency panels unless you need it to get max power out of limited roofspace. |
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| ==== Mismatched panels ==== |
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| Mismatched panels (different voltage or current [[electrical:solar:panels#specifications|spec]]) on the same controller will hamstring one another. It's [[https://en.wikipedia.org/wiki/Glossary_of_tennis_terms#unforced_error|an unforced error]] which you can avoid this by: |
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| * running //identical//((not close, not same maker, not same wattage, not kinda look the same, IDENTICAL)) panels on the same controller; or |
| * run different-spec panels on their own controller |
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| If you are committed to running mismatched panels on the same controller see [[https://www.youtube.com/results?search_query=alt-e+mismatched|this series of videos by Alt-E]] on the subject. |
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==== Not enough panel ==== | ==== Not enough panel ==== |
==== Failure to add alternator charging ==== | ==== Failure to add alternator charging ==== |
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[[electrical:12v:alt_and_solar|Adding an isolator]] can be very cheap and //supercharges// solar configs;((this effect is strongest on systems with PWM controllers)) if run at the right time it [[opinion:frater_secessus:panelsizesforinsolation|can double or triple the effectiveness of solar]], meaning one can | [[electrical:12v:alt_and_solar|Adding an isolator]] can be very cheap and [[opinion:frater_secessus:panelsizesforinsolation|can supercharge solar installs]];((this effect is strongest on systems with PWM controllers)) if run at the right time it [[opinion:frater_secessus:panelsizesforinsolation|can double or triple the effectiveness of solar]], meaning one can |
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- run more loads; and/or | - run more loads; and/or |
Yes, you can have too much battery. | Yes, you can have too much battery. |
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Most people use lead-chemistry batteries and carrying around unneeded lead is both heavy and expensive. More importantly, **having more battery than you can charge fully and regularly** results in [[electrical:batterycide|battery murder]]. This is especially true for AGM batteries which typically have a //minimum// charging current requirement of C/5 (ie, 20A for 100Ah, 40A for 200Ah). It is a rare vandweller who actually charges their AGM to [[electrical:solar:charge_controller_setpoints|manufacturer specs]] and gets a full life from them. | Most people use lead-chemistry batteries and carrying around unneeded lead is both heavy and expensive. More importantly, **having more battery than you can charge fully and regularly** results in [[electrical:batterycide|battery murder]]. This is especially true for AGM batteries which can have a //minimum// charging current requirement of C/5 (ie, 20A for 100Ah, 40A for 200Ah). It is a rare vandweller who actually charges their AGM to [[electrical:solar:charge_controller_setpoints|manufacturer specs]] and gets a full life from them. |
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Exotics like [[electrical:12v:deep_cycle_battery#lithium_chemistries|lithium]] and [[electrical:12v:deep_cycle_battery#carbon_foam_agm|carbon-foam]] aren't bothered by partial state of charge, but they are so expensive that buying too much is a self-limiting behavior. | Exotics like [[electrical:12v:deep_cycle_battery#lithium_chemistries|lithium]] and [[electrical:12v:deep_cycle_battery#carbon_foam_agm|carbon-foam]] aren't bothered by partial state of charge, but they are so expensive that buying too much is a self-limiting behavior. |
* believing one can be 100% stealth and not be noticed; and | * believing one can be 100% stealth and not be noticed; and |
* believing the opposite, that one cannot tilt the balance in one's favor of not being kicked out of a spot | * believing the opposite, that one cannot tilt the balance in one's favor of not being kicked out of a spot |
| * staying in one spot for days/weeks/months then being shocked at being kicked out |
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===== Money ===== | ===== Money ===== |
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* [[opinion:frater_secessus:beginner_mistakes#research|do your homework]]: read, browse, watch youtube videos, google, **use the ding-dang search function** of the forum, subreddit, etc. | * [[opinion:frater_secessus:beginner_mistakes#research|do your homework]]: read, browse, watch youtube videos, google, **use the ding-dang search function** of the forum, subreddit, etc. |
* when you hit a wall //then// ask for help. No one likes leeches, princesses, helpless snowflakes, or the lazy who expect others to do the work for them. | * when you hit a wall //then// ask for help. No one likes leeches, princesses, helpless snowflakes, or the lazy who expect others to do the work for them. |
* express your request as clearly and simply as possible | * express your request as clearly and simply as possible, including what you intend to accomplish |
* indicate what you do know, [[opinion:frater_secessus:beginner_mistakes#research|what you have already read]] or tried, and any important details like what you are trying to accomplish, **the make/model of any components you are using**. "My van don't go. Help." is unlikely to generate usable advice. | * shouldn't have to say this, but here we are: list **the make/model of any components you are using** and how they are connected |
* use human-readable style. Avoid run-on sentences, "wall of text" word vomit with no organization, punctuation, or paragraph breaks. | * indicate what you do know, [[opinion:frater_secessus:beginner_mistakes#research|what you have already read]] or tried |
* write a concise and specific title. "Configuring a Morningstar TS-45 MPPT" is good. "don't understand solar!!!!!!!!" is not so good. "Can anyone answer this??!?" is annoying and manipulative. Also, any title that includes the word "anyone" indicates a low-effort question. Why should //we// care if //you// don't? | * write a concise and specific title. "Configuring a Morningstar TS-45 MPPT" is good. "don't understand solar!!!!!!!!" is not so good. "Can anyone answer this??!?" is annoying and manipulative. Also, any title that includes the word "anyone" indicates a low-effort question. Why should //we// care if //you// don't? |
| * write the post in normal, human-readable style. Avoid run-on sentences, "wall of text" word vomit with no organization, punctuation, or paragraph breaks. We aren't writing masters thesis here, but make your 8th grade English teacher proud. |
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> I am always surprised to see some people demanding the time of others and meeting a most obliging response. Both sides have in view the reason for which the time is asked and neither regards the time itself — as if nothing there is being asked for and nothing given. - Seneca | > I am always surprised to see some people demanding the time of others and meeting a most obliging response. Both sides have in view the reason for which the time is asked and neither regards the time itself — as if nothing there is being asked for and nothing given. - Seneca |
* is the responder an idiot, a druggie, a zero-experience dreamer, a poorly-informed blowhard, a black/white thinker? | * is the responder an idiot, a druggie, a zero-experience dreamer, a poorly-informed blowhard, a black/white thinker? |
* is the advice upvoted/downvoted/liked by onlookers? | * is the advice upvoted/downvoted/liked by onlookers? |
| * is the advice commented on favorably by onlookers whose opinion you value? |
* does the responder have experience and/or training in the area? | * does the responder have experience and/or training in the area? |
* does the responder expect you to believe him/her as gospel? | * does the responder expect you to believe him/her as gospel? |