Questions about battery bank and generator charging.

Let me start by saying I am no electrical engineer. I have learned a lot about electrical systems in the past few weeks, and there is still much to learn.
I plan to set up a basic electrical system in the back of a cargo van. I know I am going to need a battery bank, either a large 12v deep cycle or a set of 6v golf cart batteries. My questions are related to charging this system. I understand if I plan to use a generator, it is more efficient to use an external charger than if I were to use the 12v built into the generator (if available). I am wondering if anyone could explain or link to an explanation of the different types of chargers.

I want to know what is the fastest way of charging a battery bank, while being safe. Do 6v batteries charge any faster than 12v? Do smart chargers charge faster, or would it be better to have a "dumb" charger and just keep an eye on the voltage?

The goal is stealth, while I would love to have a nice solar set up unfortunately that is out of my price range. I will end up buying an inexpensive gas generator, but as they are very loud I will not be able to run it frequently.

I plan to have a pretty basic set up, lights and a fan. I will charge my laptop but it isnt a power hog, and I will get an internet modem that will need to be charged. That and my e-cigarette. I plan to run the fridge and heater on propane, as well as a stove if I need to use it.

If I were to wire the alternator of the vehicle to charge the house battery bank, at what rate would it charge? I understand I can purchase a larger alternator. At less than a gallon per hour, idling a v8 is similar to some older generators. I doubt it would compare to the capacity of even a small generator.

Anyway, I would not be using the generator for appliances, it would be solely for charging. Are there generators designed specifically with rv charging in mind? Which battery charger would be best for use with a generator? Would it be worth the money to go with a propane generator, since I will have an LP system?

I have seen solar trickle chargers, they are relatively inexpensive compared to full sets with a charge controller etc. I assume because they arent worth much as far as charging capacity, more of a maintainer. Does anyone have experience with these trickle chargers? Can anyone compare them to the rate of an alternator?

Sorry for the flood of questions. I am still actively researching the subject, and I will edit this post as I learn.

Thanks in advance,
Mac

Mac, good to see ya over here.

I'm gonna leave most of your questions to those who tell it better.

Yes, you're right, those little panels are strictly maintenance trickle.
You can get started with solar most likely cheaper than a cheapo genny. They don't last long anyway from what I've heard.

Anyhoo, look around the site....great people here and Bob (owner) has a blog with lots of info and tutorials.

J

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bindi&us said:

Mac, good to see ya over here.

I'm gonna leave most of your questions to those who tell it better.

Yes, you're right, those little panels are strictly maintenance trickle.
You can get started with solar most likely cheaper than a cheapo genny. They don't last long anyway from what I've heard.

Anyhoo, look around the site....great people here and Bob (owner) has a blog with lots of info and tutorials.

J

`

Click to expand...

I have seen solar kits posted here for a few hundered dollars, controller and all. I am just worried, to be honest. I have read a lot about solar power systems and it is just intimidating, plus the technology is pretty new so I figure if I can hold out as long as I can with a genset the prices will drop even further. I feel like I can keep a 6hp honda running a whole lot easier than troubleshooting my charge controller and electrical system, last thing I want is to spend so much investing in the idea that solar would support me, then having to go buy a generator when I discover the sun just wont carry me with parts I have choosen.

Some solar panel kits w/everything.

This one is pretty good....
http://www.amazon.com/200W-Mono-Sta...d=1393813109&sr=8-14&keywords=solar+panel+kit

Or, you can start here....(installed this for a friend, nice products)
http://www.amazon.com/Solar-Panel-S...id=1393813729&sr=8-2&keywords=solar+panel+kit

And, add this one soon as you can....
http://www.amazon.com/RENOGY-Monocr...id=1393813729&sr=8-5&keywords=solar+panel+kit

Free shipping is a plus.

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Solar technology is far from new and much less complicated than you might think. I'm just good at all explaining (but do understand) all the numbers/etc, but have used solar for quite a while.
Others here will fill you in and there are some great threads too.
See what works for you.

The 12v output on generators is unregulated and not very much amperage. Do not bother with it.

Use the generator to power a RV converter/charger like Pd 9260 or Iota DLS-55, or PowerMac pm4 series. The Powermax in 75 amp and up ratings are power factor corrected and can run on regular 15amp AC receptacles

These come in different amperage flavors and all have slightly different algorithms that each manufacturer thinks is the best compromise between quick charging and safe charging and water loss. The 9260c is a 60 amp charger.

Rv converters are like HD chargers that do not get confused like a regular battery charger will, when there is a load on the battery whilst charging.

In theory 12 volt batteries should charge quicker, but it will likely not be measurable. 6v Gc batteries will handle more abuse. They are taller if that is a factor in mounting locations....

it is the batteries which determine how much current they can accept at the voltages driven by the charging source. Higher voltages mean more amps can be forced into the battery.

Yet once a certain point is reached the amps required to hold and not exceed the maximum allowed voltage tapers, and recharging slows down. Feeding them higher currents with a more powerful charger will get them to the stage at which the amps taper quicker, and is harder on the batteries. But batteries prefer to live at higher states of charge. Getting them higher for limited generator run time is better than babying them with a slower less abusive charge. Recharging back to 100% with a generator is unwise. That last 20% takes a long long time no matter the charging source and most who do generator recharging will cycle the batteries from 50% to 80% or so, and then when they have access to grid power will do a full recharge. Some do 50's to 90% which will take ~twice as long as 50 to 80's.

Having solar is great for the last 15%, and its ability to lessen the amount taken from the bank during the daytime

Alternators are not the masterful magical battery chargers that most people think. Their energy is neither free nor quick, despite being able to deliver high currents at high rpms, at least until they warm up.

In many vehicles, Idling to recharge is a supremely ineffectual waste of gas. A hot alternator spinning at idle speeds might not be able to make 1/10 of its rating at engine Idle speeds. Or it might be able to make half. Mine cannot make more than 32 amps at 500 engine rpm when warm yet can make ~60 amps at 800 rpm and I have a significantly beefed up charging circuit, and a smaller pulley which spins the alternator faster.

As for which battery, generator, and charger to get which will best match each other, there is no perfect. I'd spend more on a quiet Small Honda that I would run for longer with a less powerful converter as opposed to a loudass contractor generator to power a a 100 amp PM-4 powermax.

There is no right answer. Everything is a compromise.

Knowing how much battery power will be consumed, in amp hours is the best starting point. If you are still in a stick and brick you can get a Kill a watt meter which will measure consumption of your appliances and then can do some math and figure out the amp hours needed and the charging sources required to do 50 to 80's in the least amount of time for the least amount of gas.

Idling the engine for doing 50 to 80's will not work well on most vehicles, as well as possibly being bad for the engine, and doing 80 to 100% via idling the engine is just throwing away money.

Utilize every and all charging sources available to keep batteries at as high a state of charge as possible, but don't waste money to do so. Using petroleum to bring them above 85% or so, is wasting money.

They are just batteries, they are only rented anyway. Why spend 300 dollars in fuel to extend the lifespan of a 200$ set of batteries

bindi&us said:

Some solar panel kits w/everything.

This one is pretty good....
http://www.amazon.com/200W-Mono-Sta...d=1393813109&sr=8-14&keywords=solar+panel+kit

Or, you can start here....(installed this for a friend, nice products)
http://www.amazon.com/Solar-Panel-S...id=1393813729&sr=8-2&keywords=solar+panel+kit

And, add this one soon as you can....
http://www.amazon.com/RENOGY-Monocr...id=1393813729&sr=8-5&keywords=solar+panel+kit

Free shipping is a plus.

---

Solar technology is far from new and much less complicated than you might think. I'm just good at all explaining (but do understand) all the numbers/etc, but have used solar for quite a while.
Others here will fill you in and there are some great threads too.
See what works for you.

Click to expand...

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Those are the ones I was referring to when I said they were cheaper than I had originally thought. The power without the cost of fuel is amazing, the only thing that was keeping me from considering solar on the initial build was the up front cost of the panels. Those sets look great to start with, and they have potential for upgrade which is wonderful. Are those controllers decent, or would it be in my best interest to buy the panels and a higher quality controller? Eh, Im off to read the rv battery charging puzzle again, see what I can come up with as far as best options. Thanks for the replies guys, definitely considering solar from the get-go now.

SternWake, I had a feeling you'd pop in on this one.

Thanks neighbor.

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Mac, I don't know where you are or plan to travel.
We traveled for 8 months last year (Az, Nv, Or) and wintering in S. Az.
All our power needs are supplied by solar when parked. We don't use our gas hog Onan genny, but don't use things like microwave and coffeemaker, and in climates where we don't use the A/C up top.
We're a lot more conservative than a lot of RVers.

For us...increase solar and switch to four 6V g-cart batts this year.

BTW...I was a vandweller a lot longer than an RVer

This is the charger I have and it works very well:
http://www.amazon.com/Schumacher-SC-10030A-SpeedCharge-Automatic-Maintainer/dp/B001MYWBF0/

It's a "smart" charger which means it reads the voltage of the battery and automatically adjusts the amps it puts in so you get the most in as quickly as it can for your battery. It has 2, 12 and 30 amp settings and a 100 jump setting. Highly recommended.
Bob

SternWake said:

The 12v output on generators is unregulated and not very much ampera...

Click to expand...

(shortened for length)

Somehow I missed this post. It is extremely helpful, and I thank you. It seems like the best option for me is to go with solar panels, that way I will be able to (efficiently) charge the batteries fully as well as keep them maintained. The generator would have to be run quite frequently, and like you mentioned that is not very efficient, or good for the batteries.


I plan to get a decent battery set up, and I might as well do things right and set up a tilt-able panel on the roof. I will probably get 2 6v golf cart batteries, since I have seen first hand just how long these things last running them dead. In an article I read the author mentioned that certain batteries require a certain voltage held, otherwise they will never charge completely. That certain charge controllers limit at 14.2 or 14.4 volts, when some batteries require 14.6-14.8. Does anyone know which charge controllers have adjustable voltage?

If I can get a solar system set up that will handle my needs, I cant imagine wishing I had a generator. I can see driving around trying to find a remote place to run my generator getting old.
I will try to get an estimation of my current power consumption, though I'm betting it is not much.

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akrvbob said:

This is the charger I have and it works very well:
http://www.amazon.com/Schumacher-SC-10030A-SpeedCharge-Automatic-Maintainer/dp/B001MYWBF0/

It's a "smart" charger which means it reads the voltage of the battery and automatically adjusts the amps it puts in so you get the most in as quickly as it can for your battery. It has 2, 12 and 30 amp settings and a 100 jump setting. Highly recommended.
Bob

Click to expand...

That charger looks nice, I might end up getting it as back up to solar. Though everything I read suggests if I can be energy conscious, I will not need a back up charger.

http://www.cheaprvliving.com/basics-solar-power/ This webpage was very helpful, on top of everything else I've read Im pretty confident I can wire up a successful system.
That link mentions the trojan t105s, those are the batteries I am currently considering. The trojan webpage suggests a daily charge of 14.8 for 12v flooded systems, and I am having trouble finding a charge controller adjustable that high. The article also mentions wiring more than one panel in series, can anyone explain how that works, and what the benefit of that would be?

If you start out right and think ahead you'll save bucks down the line by not having to change out under rated wire and other components in the system. Think of possible expansions/additions you might like to do.

I can't seem to locate it right now, but Bob did a very good tutorial series on wiring, connections, and such.

Bob....HELP Please :huh:

bindi&us said:

SternWake, I had a feeling you'd pop in on this one.

Thanks neighbor.

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Mac, I don't know where you are or plan to travel.
We traveled for 8 months last year (Az, Nv, Or) and wintering in S. Az.
All our power needs are supplied by solar when parked. We don't use our gas hog Onan genny, but don't use things like microwave and coffeemaker, and in climates where we don't use the A/C up top.
We're a lot more conservative than a lot of RVers.

For us...increase solar and switch to four 6V g-cart batts this year.

BTW...I was a vandweller a lot longer than an RVer

Click to expand...

---

bindi&us said:

If you start out right and think ahead you'll save bucks down the line by not having to change out under rated wire and other components in the system. Think of possible expansions/additions you might like to do.

I can't seem to locate it right now, but Bob did a very good tutorial series on wiring, connections, and such.

Bob....HELP Please :huh:

Click to expand...

Just realized I didnt answer your previous post, I am from Virginia. I plan to travel around this area into the mountains, I will probably end up heading west after some time.

I am trying my best to lay out the ideal setup, after all you shouldnt start building a house until you know what you want in it / it to look like.
I would love more information on wiring, that and fuses and such to make the system safe. I have read about people using as small as 10 gauge wire, to as large as 4.

I am trying to start out with decent batteries, as well as a controller I wont need to upgrade. That is my primary concern with the all-in-one solar kits. The inverter is also important, though I am trying to set up the majority of things on 12v. I am getting tons of great ideas from others who have done similar projects, I cant wait to put together my own.

I have not been researching the latest options in solar charge controller offerings. Generally there are two types, PWM and MPPT.

Mppt controllers are much more expensive and make claims that they can harvest upto 30% more from the solar panel(s). Some are much better than others at optimizing the current into the batteries than others.

Wiring Solar panels in series requires A Mppt Controller. Wiring in series allows one to use thinner wire between panels and charge controller. Higher voltages cause less voltage drop. Mppt controllers are more susceptible to voltage drop caused by too thin a wiring between the two.

I have a BlueSky2512i MPPT controller. Unlike most MPPT controllers this one cannot handle 2 (or more) nominal 12 volt panels in series. It does however, with the addition of the IPN proremote battery monitor, allow me to change the acceptance and float voltages. I wish I had spent the extra $$ for the 2512ix model which has a battery temperature probe.

Anyway it has been operating fulltime since October 2007 without issue.

With PWM controllers one is limited to 12v nominal panels, one might be able to hook 24v panels to the controller without making it release the magic blue smoke, but the extra voltage is not turned into extra amps into the batteries.

MPPT is most effective when one has limited roof space and needs to squeeze out everything possible from the panels. Also in Cold temps, where solar voltages are higher, and with low battery voltages, that is the only times when the 30% more claims might be realized. Today the extra cost MPPT over PWM means one can just add another Solar panel for cheaper than the cost of going with MPPT.

Trojan t105's are pretty much the benchmark golfcart battery, but many report excellent results from the other 6v GC offerings from Sams Club and Costco as well, along with a significant savings over the Premuim priced purple Trojans.

The 14.8v is no lie. They do require being held there for a certain amount of time to reach full energy density, and higher than that in colder temperatures.

Many people on other RV forums use high amperage converters for doing 50 to 80/90's on generator, even if the converter does not do 14.8v. They then use other methods after an excursion when grid power is available to get the voltages high enough to return specific Gravity to the maximum baseline. Fulltimers do not really have this option.

Powermax Converters in the higher amp versions have a internal voltage Potentiometer one can dial in so that one can dial in 14.8v.

Best Converter.com sells these and knows which models have this desirable feature.

It is great if you can get away without a generator. I find my batteries like a morning blast of higher amperage from my alternator, even if short lived. The Physical agitation of driving while the alternator is feeding them high currents might be part of it too. The Solar low and slow is great afterwards, but most batteries say to feed them a minimal initial (bulk) current, and rarely can solar meet these, even if numerically, they can replace the amp hours used the night before.

While any solar is better than no solar, solar is low and slow, it ramps up slowly, peaks around noon and then tapers down. It hardly meets the manufacturer recommendations which assume you are going to attach a grid powered charger which will instantly meet the minimum bulk charging requirements and hold them for the time required to return 105 to 120% of the energy taken from the battery the previous discharge cycle.

For this reason, and due to the fact that sunlight is not a guarantee, and that murphy was an Optimist. I recommend as much solar as you can afford and can squeeze on the roof. Electrical needs change, and rarely do they decrease in this lifestyle.



My 130 watt Kyocera panel was 730$, sans delivery charge, in '07.

SternWake said:

I have not been researching the latest options in solar charge controller offerings. Generally there are two types, PWM and MPPT.

Mppt controllers are much more expensive and make claims that they can harvest upto 30% more from the solar panel(s). Some are much better than others at optimizing the current into the batteries than others.

Wiring Solar panels in series requires A Mppt Controller. Wiring in series allows one to use thinner wire between panels and charge controller. Higher voltages cause less voltage drop. Mppt controllers are more susceptible to voltage drop caused by too thin a wiring between the two.

I have a BlueSky2512i MPPT controller. Unlike most MPPT controllers this one cannot handle 2 (or more) nominal 12 volt panels in series. It does however, with the addition of the IPN proremote battery monitor, allow me to change the acceptance and float voltages. I wish I had spent the extra $$ for the 2512ix model which has a battery temperature probe.

Anyway it has been operating fulltime since October 2007 without issue.

With PWM controllers one is limited to 12v nominal panels, one might be able to hook 24v panels to the controller without making it release the magic blue smoke, but the extra voltage is not turned into extra amps into the batteries.

MPPT is most effective when one has limited roof space and needs to squeeze out everything possible from the panels. Also in Cold temps, where solar voltages are higher, and with low battery voltages, that is the only times when the 30% more claims might be realized. Today the extra cost MPPT over PWM means one can just add another Solar panel for cheaper than the cost of going with MPPT.

Trojan t105's are pretty much the benchmark golfcart battery, but many report excellent results from the other 6v GC offerings from Sams Club and Costco as well, along with a significant savings over the Premuim priced purple Trojans.

The 14.8v is no lie. They do require being held there for a certain amount of time to reach full energy density, and higher than that in colder temperatures.

Many people on other RV forums use high amperage converters for doing 50 to 80/90's on generator, even if the converter does not do 14.8v. They then use other methods after an excursion when grid power is available to get the voltages high enough to return specific Gravity to the maximum baseline. Fulltimers do not really have this option.

Powermax Converters in the higher amp versions have a internal voltage Potentiometer one can dial in so that one can dial in 14.8v.

Best Converter.com sells these and knows which models have this desirable feature.

It is great if you can get away without a generator. I find my batteries like a morning blast of higher amperage from my alternator, even if short lived. The Physical agitation of driving while the alternator is feeding them high currents might be part of it too. The Solar low and slow is great afterwards, but most batteries say to feed them a minimal initial (bulk) current, and rarely can solar meet these, even if numerically, they can replace the amp hours used the night before.

While any solar is better than no solar, solar is low and slow, it ramps up slowly, peaks around noon and then tapers down. It hardly meets the manufacturer recommendations which assume you are going to attach a grid powered charger which will instantly meet the minimum bulk charging requirements and hold them for the time required to return 105 to 120% of the energy taken from the battery the previous discharge cycle.

For this reason, and due to the fact that sunlight is not a guarantee, and that murphy was an Optimist. I recommend as much solar as you can afford and can squeeze on the roof. Electrical needs change, and rarely do they decrease in this lifestyle.



My 130 watt Kyocera panel was 730$, sans delivery charge, in '07.

Click to expand...

Once again thank you for the elaborate reply. Lots of helpful information.
It should be no problem to run the alternator daily, although I was hoping I wouldnt have to wire the house batteries to the starter. Doesnt the alternator stop providing charging power when the starting battery is full?

So what benefit is there to running solar panels in series, if you use large enough wire to counteract voltage drop?
130 watt panels are much cheaper than $700 now, seems like a good time to set a system up, haha. Seriously though, what differences are there between brands of solar panels with the same wattage rating? I understand some panels with different ratings are different sizes, but are there different panel technologies I should be aware of before shopping around?

Upon typing bestconverter.com, I realize i had visited that site earlier today, only to leave because the layout bothered me.. Looking at it again it could definitely be organized better, maybe a category or two added.. Anyway that is irrelevant and I should be able to find information on the controllers/converters from there. Thank you again.

I also read a shadow a few inches in size, even if that only makes up a small percentage of the entire panel, can cut the efficiency of a panel tremendously. Obviously clouds can get in the way, but I read people still get some power when it is raining. The only other problem I can think of is snow covering the panels.
Another question- is there any difference between 2 100 watt panels and 1 200 watt panel? I would like to get something that has upgrade potential, that is if I need it.

The main benefit of solar panels wired in series is thinner wiring needed. Also in general the higher wattage panels are 24v panels, and a little bit cheaper per watt than the 12v panels.

Different panels are affected differently by partial shading. It depends on how the internal diodes are oriented on each panel. Really for such specific solar panel questions the forum at Arizona wind and sun is the place to ask. I can't even scratch the knowledge base over there.

My kyocera panel is seriously compromised by a fat overhead powercable shadowing it. I cannot make recommendations as to individual panels and which will be most shade tolerant.

There are many ways to get alternator current to the house batteries and still have electrical isolation of the 2 battery banks with the engine off. Definitely take advantage of alternator currents. When batteries are really thirsty, it can quench them, if the straw(cabling) is thick enough. Yet at the same time it is not good at fully rehydrating them. If you are driving anyway you'd be foolish to not take advantage of that charging source. Foolishness also occurs when petroleum is burned only to recharge batteries, especially in the 80%+ zone. Generators are sometimes necessary evils. When campers have high morning demands such as hair dryers or electric coffee makers and microwave use, then they are great to use so as to not just kick a beaten dog. Batteries when depleted and asked for high currents from the above devices will protest greatly at such treatment.

A fully charged starting battery can limit current to house batteries. Fat cables between alternator to isolator device to house batteries eliminate a good percentage of this occurrence. It is when a cable is added from engine battery to isolator to house bank that the starting battery can most negatively effect current making it to house bank. Going directly from alternator to isolator to house bank bypasses this. Even if the power for the house batteries is taken from the engine battery, the house batteries will still get charged. Especially with fatter cabling to the house batteries. A problem with this is it relies on the stock alternator charging circuit which was never designed to recharge a dead battery. It was designed to keep a nearly fully charged battery fully charged and powering all vehicular loads. Tacking on a large thirsty battery bank on the end of this circuit is not what the engineers had in mind, and the beancounters would never let them if they did. A parallel cable from alternator to isolator to house batteries, properly fused, makes the weak spot the alternator itself, instead of the original inadequate alternator circuit.

Maximizing alternator current into a thirsty set of house batteries is hard on an alternator. It was not designed for this task and will wear out quicker. It is something to be aware of and factored into the equation. It is platform dependent on how much shorter the lifespan will be. It is the heat that gets them. They create tremendous amounts when asked for everything they can make. I have not replaced my alternator since I got solar, but did so several times before said acquisition. Lifetime warranty came in real handy, but I suspect many of the rebuilds were pure junk, and finally I wound up with a good one. It does get a workout though.

You must factor into the equation how difficult alternator replacement will be and replacement cost, parts, and labor if you cannot do it yourself. Upgrade if possible. A higher rated alternator very well might not charge the batteries any faster than its lower rated counterpart. More likely it can handle the heat it does generate though. Alternator ratings must be taken with a large grain of salt. Their ratings come when tested in a lab, when cold, at high rpm hooked to devices capable of asking for everything it can possibly make, over cabling that can pass that much current. This in short, never happens inside an engine compartment. Many people get high rated alternators and thump their chests strutting with bravado thinking their 160 amp alternator can recharge their battery in a half hour. This is simply impossible. It is very possible that the higher rated alternator actually produces less amperage at idle speeds than the lower rated version.

One can reduce stress on the alternator by not using fat cabling to feed the house bank. I personally want everything the alternator can feed a thirsty battery even if it exceeds the battery manufacturer recommendations. My current alternator deals with this task, but my drives are fairly short duration. I'd rather more make it into my thirsty battery than artificially limit it in an attempt to baby the alternator, or battery for that matter


Still I recommend making sure it is capable of feeding the house bank, and feed it well through adequate cabling. My alternator is rated for 130 amps. I have seen it do almost 110 briefly. Batteries cannot really take this much current for long, nor ask for it for long, and it is they which control how much they want. The vehicle's voltage regulator allows the alternator to make only what the batteries can take without exceeding the maximum voltage. IE when the batteries are depleted the alternator will make everything it can at any given rpm until the maximum voltage is reached, and this can take a while with large depleted batteries. Once the max voltage is reached, the amount of amps required to hold that voltage keeps decreasing.

Also since it is safer to under charge a battery than to overcharge one, generally the maximum voltages allowed by the vehicle's regulator are lower than ideal, and shorter lived than ideal. My '89 dodge will drop to 13.7v very prematurely, yet allow 14.9v before that. While 45 amps might have been required to hold 14.9, only 13 amps might be required to hold 13.7 perhaps even less. So there is that. Different vehicles will perform differently in this regard as to voltages allowed, but less amps will always be required to hold lesser voltages, and thus recharging slows down considerably.
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Amazing how a website layout can make or break interest. I just browsed all the wireless carriers shopping for plans and Smartphones, and was willing to spend a bit more just because the website layout was more amenable to my tastes. Went with Ting( pay what you use), and a galaxy s4 mini and expect my bills to be half of what I pay paying AT&T with a feature phone that was so clunky that using the internet on it was not worth the effort.

Randy at best converters is apparently good to talk with. I have not done business with him. I am interested in Powermax converters and he seems to have an inside line with them and has contributed to their design parameters. I am using a Schumacher charger, but it has issues with cycling loads on the batteries while they are charging, but now I isolate the charging battery switching loads to the other, when I use the grid to recharge.

Generally a 200 watt panel is going to be a 24 volt panel requiring MPPT. Also such a panel is big enough UPS and other similar carriers will not ship it. it will have to go freight, and thus cost more.

Solar panels are pretty tough things, but one big panel could perhaps, at highway speeds under certain conditions, have pressure exerted in such a manner as to exceed the glass rating. 2 100 watt panels would have less surface area without support for wind to push on. Might not be a factor. Again platform specific.

Another thing to keep in mind is that it is easier to use less electricity than it is to create it. LED lighting is one of the biggest places where energy can be saved. Laptops can use a lot as well. See if there is a "car Adapter" for your make and model. this is much more efficient than using an inverter to power the original power brick. Inverters are seen by many as a solution for everything. Some even will put a huge inverter in a battery bank that is incapable of delivering half the inverters rating for a minute before the low voltage alarm begins. Inverters in my opinion are a necessary evil, but a last resort, certainly not the first option and certainly not a solution.

Also Things that use a USB port to recharge, the least desirable device for powering a USB port is an inverter.

2 golf cart batteries is a good amount of storage, and I would definitely recommend 200 watts of solar for that capacity. Even if you only use 30 amp hours per night, the batteries will last longer with 200 watts on the roof compared to one hundred. 100 watts will have little issue returning 30 amps hours used overnight, but 200 watts will do it sooner in the day, and allow more time the rest of the day to squeeze in all it can to batteries which are resisting that full charge. Have a week of cloudy weather and those GC-s are down in the danger zone, you will be thankful when that cold front passes and you have 13 amps refilling that thirsty battery bank, instead of 6.5.

SternWake said:

The main benefit of solar panels wired in series is thinner wiring needed. Also in general the higher wattage panels are 24v panels, and a little bit cheaper per watt than the 12v panels.
...

Click to expand...

I dont understand why people use smaller wire than they should be using, besides the price, since wire is pretty much a one time thing that wont break. Is there any disadvantage to using wire that is too large? I understand having 0/00 gauge wire would be overkill and look ridiculous, but would it compromise the system in any way?

I am glad you specified the difference between wiring starting battery>isolator>bank and alternator>isolator>bank, as most of the information I have read suggests to wire it from the starting battery. ??
This subject remind me a lot of the computer field, many people want to think they know what is best without doing the research required.
It seems like it may be best to run the alternator to raise it above 60-65%, then let the panels take it from there. Though ideally the batteries will not get that low.

Regarding the laptop, since computers convert ac to dc anyway, does anyone have experience with the difference in charging times between the ac power supply the laptop comes with and an equivalent 12v system? I know I have seen power supplies for desktop style computers that are designed to run on DC.
I will probably purchase 2 100 watt panels if there is no benefit to larger panels, the shipping is a plus as well.

I will probably get a battery charger as well, that I can plug into a standard outlet. A question regarding charging the 6v golf cart batteries in series, would you charge each battery individually or would you connect the positive to one battery, then the negative to the other while they are still connected?

Another question regarding battery equalization- I read that 2 6v batteries at the same amp hour capacity/output as one deep cycle 12v would last longer because they are constantly equalizing due to being connected? I am not sure as to what actually goes on here, though I assume equalize means the batteries will transfer charge whenever one is at a higher voltage.
Is it worth it to invest in a hydrometer? I know several people have one, but they rarely use them. Supposedly a battery meter cannot be completely accurate, but is the difference in accuracy enough to warrant opening the battery to get a real voltage value?

LED lighting is what I plan to use. This is one of the reasons I do not want to go with a conversion van, despite them being more attractive to me than the creepy cargo van look. I would have to redo the insulation, redo all the lights to leds, cover windows I do not use, and there is still a lot of wasted space designed to make it more comfortable for passengers. All this before I even get started, I will just start with a cargo van.

Another question, bit off topic- Does anyone here have any recommendations for hi-top manufacturers? This would be the main reason to get a conversion van, though most conversions are not extended. When browsing hi-tops most of them seem to cost more than a whole van, and its just fiberglass. :huh:
I will probably do without one for this reason, plus mounting solar (or anything) on fiberglass is challenging.

You will have a positive from one batt and negativve from other batt free. These act just like the posts of a 12v so you hook everything thru those. The other posts will be connected with a short fat cable connecting the batteries

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Also..i hooked the renology 100 watt kit up last week...if we did it anyone can lol Do wish they made the end cord longer tho (from connector to inside van).

I am extremely happy with my solar, but there have been times when it runs out, so having a backup is still a good idea. Once in the winter in Pahrump Nevada (50 miles due West of Vegas) we went a week with snow and rain and ran out of power. This last summer in Flagstaff, AZ we went 3 weeks without seeing the sun and there were about 8 of us camping together and we ALL ran out of power. The whole summer was incredibly rainy and we all struggled the whole time.

Bindi, at the top of the page is a series of menu buttons. If you go to any other page on the site there is a series of buttons underneath it. One of them is "Electrical" and one of them is "Solar." Hold he mouse over them and the pages on those topics will drop down. The Crimp and Strip pages are there. I never did get to a page on wire gauges. Just haven't had time. One of these days!

The forum looks like those pages but it uses different software. Eventually I will get those buttons on the forum too.
bob

akrvbob said:

I am extremely happy with my solar, but there have been times when it runs out, so having a backup is still a good idea. Once in the winter in Pahrump Nevada (50 miles due West of Vegas) we went a week with snow and rain and ran out of power. This last summer in Flagstaff, AZ we went 3 weeks without seeing the sun and there were about 8 of us camping together and we ALL ran out of power. The whole summer was incredibly rainy and we all struggled the whole time.

Bindi, at the top of the page is a series of menu buttons. If you go to any other page on the site there is a series of buttons underneath it. One of them is "Electrical" and one of them is "Solar." Hold he mouse over them and the pages on those topics will drop down. The Crimp and Strip pages are there. I never did get to a page on wire gauges. Just haven't had time. One of these days!

The forum looks like those pages but it uses different software. Eventually I will get those buttons on the forum too.
bob

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http://www.cheaprvliving.com/blog/h...te-lighter-plug-strip-and-crimp-12-volt-wire/

This page and the comments that follow were very helpful. I noticed a few of the picture didnt load, but the important one did. Between this website and good old google, I definitely know far more than I did before about 12v systems.

I am wondering if anyone has information regarding fuses, specifically in 12v systems. Last thing I want to do is short out and start a fire, or worse have my batteries explode.
Though as long as I wire thing competently, I shouldnt be pinching wire etc.

The bigger risk will probably be my LP system, I know there are specific laws regarding having propane in a vehicle that vary from state to state. Sure would be easier if there was a national/international standard.

If you don't want to put your panels on the fiberglass roof of a high top, you might consider portable solar. I bought a 70 watt Renogy panel and 30 amp Renogy controller through Amazon and they work great. I bought the larger controller as I plan on adding another panel and this controller had the correct charging voltages for my 100 ah AGM battery (float is a bit high, but I can just disconnect the panels when the battery is charged). I used 10 gauge wiring throughout which will be fine when I get the other panel. Wired through the bottom of my battery box, into the van with the controller less than 2' from the battery. Panel stand is just a little metal saw horse I got at a flea market, with hooks attached to the panel. I can tilt with an extended curtain rod. My power needs are light and 140 watts will be sufficient for me. I do, however, have a generator if needed, however, the converter in the RV does not charge with the correct voltages so I wanted solar to make my battery happy!
I am an old lady.....if I can do it, so can you! LOL. Have fun....(my brain turned to mush studying amps, watts, wire gauges/lengths of run, etc, etc)

Bela said:

If you don't want to put your panels on the fiberglass roof of a high top, you might consider portable solar. I bought a 70 watt Renogy panel and 30 amp Renogy controller through Amazon and they work great. I bought the larger controller as I plan on adding another panel and this controller had the correct charging voltages for my 100 ah AGM battery (float is a bit high, but I can just disconnect the panels when the battery is charged). I used 10 gauge wiring throughout which will be fine when I get the other panel. Wired through the bottom of my battery box, into the van with the controller less than 2' from the battery. Panel stand is just a little metal saw horse I got at a flea market, with hooks attached to the panel. I can tilt with an extended curtain rod. My power needs are light and 140 watts will be sufficient for me. I do, however, have a generator if needed, however, the converter in the RV does not charge with the correct voltages so I wanted solar to make my battery happy!
I am an old lady.....if I can do it, so can you! LOL. Have fun....(my brain turned to mush studying amps, watts, wire gauges/lengths of run, etc, etc)

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I have read that you can increase panel efficiency up to 40% just by angling it towards the sun instead of laying flat. This makes sense as a flat panel is only in direct sunlight around noon, depending on the time of year and location.
Ive also read it is good to tilt the panels south, but wouldnt it be beneficial to point it east in the morning and west in the afternoon? I assume south is recommended as an alternative to flat, for panels that are mounted permanently (houses etc).
I have a pretty good grasp on the concepts of solar electricity, now it comes down to the small mistakes that make or break a system. I hope to be as close to an expert as I can get, before ordering the wrong parts. I have a pretty strong interest in computers, so the technical "jargon" is easy for me to remember once I read it enough times. Im excited to get this set up, but I am trying not to rush things. I want to make sure I get the best setup for whatever amount I spend.
I just looked at your picture, how much does a panel that size weigh? They make some really nice coaches out of those sprinters, one day when the vans are a bit more common and I know more about diesels I will probably get one. How does it do accelerating up hills?