Learning all I can about RV solar & batteries.

[GrantRobertson]

I am trying to learn all I can about solar & batteries for systems appropriate for anything from vans to large RVs. I used to be an electronics technician but that was a long time ago.

I have read what I could find on the internet. Jack Danmayer's site is OK but does a lot of hand-waving around specifics and seems to lean towards the high-dollar solution to problems that may not even exist for many people. Handy Bob's site is so full of rants as to be almost unreadable. The Technomadia site is pretty slim pickings too. Perhaps they are saving the good scoop for an upcoming book. Even the A M Solar site is pretty thin on specifics. I have also read through most of this sub-forum and gleaned a few good generalizations. However, I know there is still a he'll of a lot more to learn on the topic.

I have looked around and there seems to be a few books on RV solar but I don't know which to get. Can anyone recommend a GOOD book on RV solar? Please only recommend books you have read and that actually helped you.

Thanks

 

[jimindenver]

Grant

For me, every user reporting on their own system is a mini blog and we do like to talk about our systems don't we. There quite a few users on RV.net with write ups on their solar in the forum or individual blogs in their signatures. There are always discussions on solar of many types, batteries, inverters, etc by people a lot smarter than me. There are many other forums like it too.

I may not always agree with what is discussed, it may not apply to me but I am interested in what they have as a system, why they did it that way and what they get out of it. Combined it is so much more information than any book and they use the latest gear too.

I hope you find what you are looking for.

 

[Spaceman Spiff]

Didn't read any books (usually outdated), but here are some of the web sites that instructed me:

https://handybobsolar.wordpress.com/
Goes on a lot of rants, but solid information.

http://www.pbase.com/mainecruising/boat_projects
Marine application, but that is applicable to RVs.  Excellent info.

http://www.cheaprvliving.com/basics-solar-power/
Good basics for small systems (like mine).

http://www.solar-electric.com/rv-solar-electric-systems-information
Good info from a vendor.

http://www.freesunpower.com/chargecontrollers.php
Follow links for info on other systems.

That should get you started   

-- Spiff

 

[MikeRuth]

Can't recommend anything because I learned almost all of it on this site. It's all here, just takes a little work to find and assemble all the info.

As for Handy Bob that is a great read but only for those who have a better understanding of it all. He has been an electrician for many years but like most of us he didn't know all that much about 12 volt systems and he has learned it in the real world and rebuilt his own systems now several times getting to the point of what you read from him. So keep his blog bookmarked, it will make sense later.

I'm of the belief that if you can tell us what you have, what you want to do and type of budget(low, medium, unlimited) then you can get all the info and instruction you need right here Grant.

I don't know if there really is anything on the market in book form that really can explain it all, in one way or another there is going to be some bias in them. people like my self here are not as biased providing you probably the best info. Lay it on us, what do you want to know?

As a side note to our fearless leader we need a reference thread. Been thinking about this a lot lately, but I'm not sure how we best go about it. IE thread links in one post that someone can keep up to date. A thought anyways.

Mike R

 

[Optimistic Paranoid]

As a side note to our fearless leader we need a reference thread. Been thinking about this a lot lately, but I'm not sure how we best go about it. IE thread links in one post that someone can keep up to date. A thought anyways.

I've suggested this, too, in the past.  The thing is, someone, or several someone's, have to step up and offer to write the stuff.  I did one sticky on wires and fuses.

I'm thinking we need one sticky on batteries, one sticky on charging from alternators, and one sticky on solar panels and controllers - that last might be two stickies.  A sticky on electric math, how to calculate loads, convert between amp hours and watts and so on.

I think I've got a pretty good handle on most of it - but I'm the first to admit that there are a couple of people here who know more about it than I do.

So how about it? Any of the really knowledgable people here want to step up and volunteer? 

Regards

 

[akrvbob]

I never could find a book that was of much use. For me it was years of trial and error and asking everyone I met with any knowledge questions. Slowly the pieces of the puzzle fell together.

But I'm still learning.

I'd say that for sure I've learned more from Sternwake than any other source. But I already had a good foundation so I could make sense of what he said, he filled in many more pieces about batteries that I had never heard before.

It's a tremendously complex puzzle, I suspect the only way to get the whole picture is one piece at a time over a period of time. That's the way it was for me.

Because of that I will almost always give the simplest answer possible to every question. Learn to handle that piece, then add another one.

Just start asking questions!
Bob

 

[29chico]

OP:  Are you considering lead acid only?  If so, just read everything that Sternwake has posted about the selection, care and feeding of LA batteries.  You will be well served.  

If you are thinking of delving into lithium battery tech, I would be willing to give some suggestions for you to research.  Lifepo4 and Lifemnpo4 chemistries are a very good choice for many reasons and can work very well without a huge investment as long as one is willing to get rather hands on at first.

i'm actually in the process of building a hybrid battery storage system that uses both LA and lithium cells and takes advantage of both of their strong points.

 

[GrantRobertson]

I am a very technical guy. I was an electronics technician for over six years, then I layed out printed circuit boards for three years before becoming a network manager. That lasted twelve years, and then I went back to college for computer science. I've turned my share of wrenches and swung my share of hammers as well.

When I need to learn something, I dig down pretty deep. Writing about things is the best way for me to learn about them. I figure if I don't know something well enough to write about it for a novice audience, then I don't know it well enough. As it turns out, I happen to be a technical writer. And a pretty damned good one if I say so myself.

So, if there are no good books on the subject AND I need to learn all I can about it, then this seems like the perfect opportunity to put together a book. Maybe not the biggest book. I don't tend to add in a bunch of fluff just to fill pages. But it will be thorough, accurate, and easy to read, even if one has never heard of electricity.

You all say I should ask a lot of questions. If I start on this project, I will definitely be doing just that. But I won't be asking what I should do in my specific situation. I will be asking exactly how things work. Which devices do what and why? What can and can't be hooked into a system, where, and why?

I would also be writing lots of "test" explanations and asking people to check them for accuracy, and to see if there are things a novice would get tripped up on. I will be creating diagrams, decision trees, and flow charts then posting them for review. The whole shebang.

What do you say? Are y'all up for it?

 

[SternWake]

I'd love some selected recommended sources for Lithium.  This is where my interest and efforts in learning about batteries now resides.

[Mod's Note: The discussion about lithium batteries has been moved here https://vanlivingforum.com/Thread-L...m-Learning-all-I-can-about-RV-solar-batteries]

  I figure my next flooded, lead acid, deep cycle battery, will be my last.  I intend to  walk into lithium ownership with as much knowledge as I now have with Lead Acid. 


But that ownership  will be after  ~ 1000 cycles to 50% DOD, after I actually acquire the battery. Right now I am cycling my AGM engine battery to 50% or below 4 to 5 nights a week and actually fully charging it each and every day, and it is, in my opinion, at this point, a dang impressive battery.  No issues with engine starting, even at 40% charged, even when I took it down to 30%.  The next flooded deep cycle battery can wait.  It should be said those other 2 to 3 days the battery is being fully charged and held at 13.6v all day, all night, unless I am driving, then it might be as high as 14.9v.  I can also choose to never even cycle a battery lower than 85%, with my current parking situation, but I do, as I want to see how well it can handle cycling deeply but being recharged fully too.

As far as Lead Acid battery Owners manuals go:

http://rollsbattery.com/uploads/pdfs/documents/user_manuals/Rolls_Battery_Manual.pdf

I cannot compile anything better, nor state it clearer, but here's the quick summary:

Know how to actually fully charge your battery, Do it often, and your battery will be happy and provide good service.  A quality deep cycle battery kept happy, will keep the owner happier for longer than a cheap battery treated well, will.

If you can't treat a battery well........., well,.......  don't spend much on your battery.

Other good lead acid User manuals:
http://www.lifelinebatteries.com/manual.pdf

http://www.cdtechno.com/resource/support_doc.html

http://www.cdtechno.com/pdf/ref/41_2128_0212.pdf

http://www.trojanbattery.com/BatteryMaintenance/Charging.aspx

http://usbattery.com/wp-content/uploads/2014/05/usb-charging-recommendations.pdf

http://www.crownbattery.com/faqs


And as far as I am Concerned, 'MaineSail'  who participates on Many boat related forums, is pretty much the battery/Dc electrical King and can explain things on his site/ you tube videos, better than I could in a hundred years of trying.

Please pick through the obviously battery/wiring/electrical related subjects on this site:

http://www.pbase.com/mainecruising/boat_projects

In selecting a battery, Know that 'deep cycle' printed on the sticker in plain site on the side of the battery, means next to nothing:
http://www.pbase.com/mainecruising/deep_cycle_battery

Please beware of product marketing.  There is no truth in advertising.

And here is a  link to some of his You tube videos:



Again scroll through his various offerings, watch them twice if it does not 'click' in your head.

This one might help the others to click faster than otherwise:


If there is need for clarification, then perhaps I can help further, But I am not so sure I can really get the 12v newbie reader to understand what I type, and I really am not good at repeating myself, without being abrasive.  36 grit at 3750 rpm on an 8 inch sander, and no apologies, except for this one, Sorry.

MaineSail completes tasks to or well Beyond ABYC code, and this can go well above and beyond what is necessary in a Van dweller system, But at the same point please  keep in mind the reason behind the anal retentiveness.  Nobody in good faith can say, 'ahhh just skip the fuses' or '  Ahhh, I used a simple household wirenut on my boat trailer and the trailer failed before the connector ever did' .......as a reason to skip making clean, tight, corrosion resistant, low resistance electrical connections.  

I skold myself when I  use only half my ass on my own projects, I cannot recommend or condone a half ass approach, I am only  really comfortable presenting 'ideal' as far as I know it to be, on this forum. 


For this reason I am reluctant to author anything which will be made into a 'sticky' as there will always be somebody to say there is no need for Ideal, or 'this and this is what I do and it works 'JUST fine''', which really only means works OK so far, and might even be a recipe for disaster at worst, or a 'less than happy battery' at best.

I am really trying to limit my time in front of this keyboard.  Too many projects I want to complete, and too much freedom, too.

 

[akrvbob]

I think the book is a great idea, But, writing without doing seems very unwise to me. If I was aware of it, I would not buy your book.
Bob

 

[jimindenver]

Again that's why the user thing works, we talk of what we do. I can tell you about what I've done good or bad but I hate regurgitating info from off the internet like I know what I'm talking about. I prefer to put together and see what happens when I push the button, now you are talking real life.

 

[Optimistic Paranoid]

Can I suggest that if you are going to start a discussion of lithium cells, it might be better if it were in it's own, easily searched for thread?

Regards
John

[Done. Mod's note: The discussion about lithium batteries has been moved here https://vanlivingforum.com/Thread-L...m-Learning-all-I-can-about-RV-solar-batteries]

 

[Optimistic Paranoid]

Handy Bob's site is so full of rants as to be almost unreadable.

I took a couple of things away from that site that I thought - and still think - are very important.

The difference between 14.4 volts and 14.8 volts may not sound like much, but it's actually very significant.

The charging rate on most solar charge controllers are usually set too low.  See what the battery manufacturers recommend as optimum for their batteries, and always set your controller to THEIR specs.  They are the only ones who really know what they are talking about.

Most solar installers use wire that is either too long or too thin or both, and it cripples solar charging systems.  Short, fat wires are the way to go.

Regards
John

 

[SternWake]

I took a couple of things away from that site that I thought - and still think - are very important.

The difference between 14.4 volts and 14.8 volts may not sound like much, but it's actually very significant.

The charging rate on most solar charge controllers are usually set too low.

  The  bulk  charge rate is mostly determined by available Solar  wattage in comparison to total available capacity.

The Absorption voltage setpoints are KEY to fully charging a battery.  It must go up high enough for long enough.

So many people blindly believe their charge controllers, that when it goes to float mode, that the battery is fully charged.

NOTHING can be further from the truth.  Once the correct absorption voltage is reached, it is to be held until Specific gravity no longer rises, or in the case of AGM batteries when the battery only requires 0.5 amps per 100AH of capacity to be held at absorption voltage.

This generally takes 2 to 4 hours on batteries discharged below 75% once absorption voltage has been attained, but this time is highly dependent on the charge rate at which the batteries were brought upto absorption voltage.

Having a charge controller that uses too low an absorption voltage and only applies it for ~ 2 hours before reverting to float voltage, is helping to destroy the batteries. A charge controller with adjustable set points will pay for itself on the first set of batteries, compared to one that does not allow this.

100% recharges can double the expected cycle life compared to 92% recharges and premature ending of absorption voltages usually leaves the battery in the 92 to 95% range.

Chico, thanks for the links.  I got a lot of research to do.  a 100 AH lithium bank would easily meet my needs

 

[GrantRobertson]

I think the book is a great idea, But, writing without doing seems very unwise to me. If I was aware of it, I would not buy your book.
Bob

That's what technical writers do all the time. A good technical writer knows how to ask the right questions, organize the information, give people the appropriate background information, and explain things so anyone can understand. Most people who are experts at the doing do an incredibly poor job of writing about it. Handy Bob's rantfest is a case in point. I'm sure he really knows what he is doing but his site is indecipherable for a novice or non-technical person.

If folks here will be willing to answer my questions, and there will be a lot of them, then I will happily do several things: The cover will say "By Grant S. Robertson and the members of CheapRVLiving.com." Of course everyone who helps will be listed in the acknowledgements. They will also all get a printed copy of the book. I will also offer a free .PDF version of the book available exclusively through the site so no members will have to pay for information that came from other members of the forum. Finally, if possible, I will give the site the exclusive right to post an Amazon affiliate link to the printed version.

I don't expect to make too very much money from the book, myself. Writing it will be a learning experience and a way to show off my writing skills. Part of how I hope to earn my living on the road is in writing and selling technical and How-To books. I grew up reading them, and I think it is a lost art, despite how many are actually on the shelves.

This project will also be good for me, psychologically, because it will give me something to focus my mind on while I wait the interminable months till I can actually get out on the road.

The first thing I will do is go back and read all the previous posts on the subject plus all the sites linked to. I will take notes and organize them. Then I will come up with an outline of what I think should be covered in the book and post that for comment.

Oh, and don't worry, Bob, by the time the book is finished, I will have done plenty of doing.

 

[akrvbob]

I'd give serious thought to self-publishing with Kindle and Createspace (on-demand physical books owned by Amazon) I think you'll make a LOT more money.
Bob

 

[GrantRobertson]

I'd give serious thought to self-publishing with Kindle and Createspace (on-demand physical books owned by Amazon) I think you'll make a LOT more money.
Bob

I'll definitely look into those. I planned to self publish and I planned to use a print on demand service. I knew Amazon had the former for Kindle, but I didn't know they had the latter.

Thanks.

P.S. I lied. I ended up creating the outline first. I will post it tomorrow morning.