My plan for power. Is it sound?

[One Awesome Inch]

My plan for power..

First off my power needs are relatively small

Two .80 mA computer fans for ventilation
One large screen smartphone - 3800 mA
One LED overhead light 1.2 watts

Thats pretty much  it for what I will use on a daily basis. I will likely only run one computer fan 10 months out of the year.

Here's what I intend to buy:

1. Two 20w solar panels measuring 20x13 inches. They will easily fit on the dashboard of my van and I will be able to easily remove them in the event that I need to be super stealthy... like at work. I have decided not to get a rooftop panel because I think it drastically reduces stealth which is super important in my case as a urbanite living in the same area (near my kids and job). I realize I will probably lose 1/2 of the 40w charging capability due to the van's windshield, but I think 20w should be adequate for my small power needs (combined with the van's alternator). Where I live it rains and/or is cloudy most of the year so not sure how well the solar will work for me, but I guess there is only one way to find out.

http://www.amazon.com/gp/aw/d/B005N..._1_4?colid=6GJ0GDWP1J9Z&coliid=I2NRYF5LYSRDF2

2. Group 27 Dual Marine / Rv battery which gives 100 amp hours and 730 cold cranks. Hopefully this will adequately start my 1999 E150. This will be charged by both the alternator and 40w of solar. I will not be driving more than 200km a week and sometimes less... like in the summer. I'm hoping the solar panels will provide what charging the alternator of my van (95amps) does not.

http://m.canadiantire.ca/en/pdp/group-27-starting-and-deep-cycle-battery-0102799p.html

3. This is the charge controller. I like that it has a digital readout and two usb outputs.

http://www.amazon.com/gp/aw/d/B00MB...colid=6GJ0GDWP1J9Z&coliid=I1RNXVN9QWR0RN&vs=1

Any potential drawbacks here?

Your opinions are appreciated.

 

[Baloo]

Hey there,
I will throw my thoughts at this. I have 200w of soar and a 30amp controller (already looking at replacing it with a mppt controller).

I would suggest keeping the engine and house batteries separate (you will always be able to start the van no matter how dead the house battery). You can either charge them individually (engine battery from alternator, house battery from solar) or installed a combiner. Some people use isolators, but they actually use some power making a small solar system even smaller.

Those panels look like polycrystalline panels. I would move up to monocrystalline (they are more efficient). Also, they only produce 1.3a each, making it a 2.6 amp charge in perfect sunny conditions. Plus any voltage loss from wiring.

I start off with one panel, thinking 100w would be awesome and more power than I would ever need, Wrong! I have all LED lightening, and a very efficient power grid, and I am already looking at installing one or two more panels.

Honestly, 40w is not much more than a trickle charge. In my opinion, you will not have enough solar charging to make your system work happily.

Again, this is my opinion from my experience. Please don't take it from my word, do some more research. You will be happier in the end. If you want my advice feel free to pm me and I will offer all I know and am currently learning about solar power.

Good luck,

Baloo

 

[SternWake]

Well the Solar, controller,  and shipping are going to cost as much as a replacement 12v marine battery.

Your smart phone is not drawing 3.8 amps at 12v.  I have a hard time  believing it takes 3.8 amps at 5v.  A freaking ipad only takes 2.1 amps at 5v, which is 10.2 watts.

0.08 Amps is not a very strong fan.  0.08mA is not possible in a fan.  0.8 amps is a fairly powerful 120MM computer fan, and quite loud too.

Look into the silverstone fm121.  Variable speed. 0.08amps to 0.4 amps at max speed.  This is a great fan for van dwelling because of the variable speed and variable current consumption and variable noise factor, and it can move 110 CFM on Max..

Your loads are small enough that I would skip the solar entirely, as long as your loads do not increase.

Your alternator should be able to keep the battery above 80%, and it should give respectable enough service when cycled so shallowly.

I'd say to get two 8 awg maxi fuse holders and a 60 amps fuse, and enough 8 awg wire to hook alternator(+) to battery(+), and this will increase the alternator's ability to feed the battery in short trip driving.  Another 8 awg cable from battery(-) to alternator(-) will also help to charge the single battery faster in short trip driving.

These wiring upgrades do not require any removal or modification to stock wiring, these are parallel circuits, and with fuses at both ends of the (+), are perfectly safe. They also can be implemented at a later date.

Solar is great, but through your windshield, in your environment, with your stated loads, is not needed or worth setting up or worth trying to store the panels while driving.

Consider getting a Jumper pack in place of the solar for the day when you need a jumpstart.  perhaps jumper cables are enough for you too.

Your loads are also small enough that a voltmeter is good enough to guestimate battery state of charge, but it would be best if this voltmeter takes a voltage reading right at the battery, not through a ciggy plug.  The ciggy plug would just possibly read lower, making you think your battery is more discharged than it is, and if you slow down/stop discharging prematurely, well that is better for your battery, but might be inconvenient if you wanted to run your phone and fans for another 4 hours and thought you depleted it too far already.

I doubt you'll see voltages much under 12.45 under your stated loads, even if you did not drive.

If the Fans you plan on using actually consume 0.8 amps at 12v, then this throws a monkey wrench into the plans.  Such a Fan running for one hour,  consumes more electricity than my compressor fridge averages in an hour.

 

 

[Teskimo]

5 years ago, I bought a 40 watt system with built in controller and 30 amp battery and 2 florescent lights.
We spent 10 days in the national forest. We used both Iphones as well as the I pad for internet/readers.
We were able to use all the power we wanted and only had to set the panels out twice. Only because the indicator read below 10 volts in the battery.
Later I bought a deep cycle 100 amp battery for this system. I found that leaving the panels out every day in my back yard, the battery just never seemed to get a good charge in it.

I would recommend installing the panels on the roof (how visible would two small panels be?), and use a 30-60 amp battery.
Can the panels be removable if required?

 

[jimindenver]

If you will be driving anyways, use the alternator. The solar through the windshield is going to be so reduced due to the glass that it may not be worth it, First you will never see 40w even if the panels were outside and pointed right at the sun. You might see 30w. Reduce that by 50% due to the windshield and you have 15w and that's only if you are parked in such a way that the panel is directly lined up with the sun. Most of the time it wont be unless you repark every so often. That kind of power is used to keep batteries from self discharging, not replace power.

Stealth being the issue, what about the newer flexible panels without a frame. You can use high bond tape to put them up and you wouldn't know they were there except from above. More expensive than what you are looking at but it would be usable power.

 

[One Awesome Inch]

Thanks for the replies.

This is my exact computer fan. I have two of them.

http://www.amazon.com/gp/aw/d/B00314J422

Specs (http://www.amazon.com/gp/aw/d/B00314J422#productDescription_secondary_view_pageState_1431273532502)

Model - R4-S4S-10AK-GP
Dimension - 140*140*25mm
Voltage - 12VDCCurrent (Ampere)0.08A Input
(Watt)0.96W
Speed (R.P.M.)1000 R.P.M.
Air Flow (CFM)60.9 CFM
Air pressure (mmH2O)0.82 mmH2OFan Noise Level (dB-A)16 dB-A

I plan to attach a 1000k  potentiameter to them to adjust speed as required. I bought two thinking I can double them up when I need to draw alot of heat out in a stealth situtation (cant raise fantastic fan lid). 

I bought these fans thinking they are very efficient in terms of low power use. Did I get that wrong?

My smartphone is 3.8 volts not mA... oops!

LED RV lights = 1.2w each or 0.1 amps or 100 mA
Samsung Galaxy Note 3 = 12.16w / 3.8v / 3200 mA
Comp fan = .08 Amps /  input .96w (.96w = .08 amps)

So based on your guys' opinion I will forgo the solar. My main concern is that I am going to be dead broke this summer and in July / August will be driving as little as possible to save on gas. But of course this means I'll have very limited battery power from the alternator as a result. I think instead of solar I can borrow a jumper pack from a friend (he might even give it to me) and use that to power my smartphone. I have an LED lantern that does very well on some D batteries so that will cover me for light. The biggest concern is the fans which I will definitely need for the heat, and they may be running almost always, depending how much they are needed.

I have thought of those flexible solar panels and yes they are more stealthy. Still any panels on the roof can be seen from a building looking down on the van and may raise questions from my employer. Heck, I am putting in a Fantastic Fan and I am even learly of that rooftop bubble. However, I think its pretty much a necessity to have the ability to draw out a bunch heat quickly by having the fan on for 5 minutes... and also the daytime light it provides.

Anyways, thanks again for your assistance. Lots to think over.

 

[SternWake]

That fan has good specs, So good I find them a bit difficult to believe for an 8$ sleeve bearing fan.
Sleeve bearing fans do not have much of a lifespan when mounted in the horizontal plane.  They can get noisy, quickly.
The potentiometer inline on the power wire might not work for very long.  Most potentiometers are rated for 1 watt, but can only handle 1 watt for short periods. Likely it will burn up in a day or 2, or just fail to control speed.  I once tried it on a 0.18 amp fan and it lasted about 15 seconds. 
A better method for fan speed control is via pulse width modulation.
http://www.amazon.com/MOGOI-Dimming...qid=1431281533&sr=1-2&keywords=pwm+led+dimmer
Yes it does say it is for LED lighting but it works on fan motors
Another method is with a voltage controller:
http://www.amazon.com/PowerLine-Uni...1431281723&sr=1-19&keywords=powerline+voltage
I use 2 of these for my internal circulation fans( vantec tornado 80 and a 92mm)
These particular Vantec fans make a whining sound when slowed by a PWM motor speed controller.
The powerline voltage adapter allows 3, 4.5,6.7.5,9,and 12 volts for different speeds and the fan amp consumption drops significantly when slowed.  No whine either.
I like the vantech tornado's because they push out a narrow dense column of air, where as other fans emit air in 4 hotspots exiting at wider angles
68 CFM is not a lot of airflow either.  Don't think that you can park in full sun and that these are going to keep the interior as cool as it is outside the van.  they will help some.  That is all.
I happen to have about 150 CFM of fan pushing out my roof vent, a White van and can insulate all my windows, and without my intake fans on, which are located in a side window, on a hot day it is a losing battle.
All it takes is one person to see you get in or out of your van, when it does not then drive away, or has not been driven for a while for stealth to be eliminated.  Stealth assumes people have no observation skills and no deductive ability.  There are a lot of self absorbed texting nimrods out there, but one can't and should not assume that you can go unnoticed indefinitely, and the very act of being careful about entry and exit can be suspicious.
Two solar panels on your dashboard are going to scream Van dweller just as much as one on the roof.
I think perhaps you are putting all your eggs in to the stealth basket, and the stealth basket is full of egg size holes.
What will be the consequences for discovery? 
 Plan to accept them. 

 

[One Awesome Inch]

The consequences for discovery... worse scenario is that I lose my job. To that end, I am considering parking the van a 15 minute walk away from my place of employment. I really don't care if friends and family know. I am who I am... they can accept me or not. Their choice.

I agree with your point of view that eventually the stealth thing is not going to work. I will have to park my van near my kids place and eventually someone in the neigbourhood might figure it out. I guess I'll cross that bridge when I get to it. I do have a partition wall and will only be entering my living quarters thru the partition door when in 'stealth' mode. I will only be entering the van itself thru the driver's door.

As to the fans they will be mounted behind my rear license plate vertically. I do plan to run a Fantastic Fan to suck out hot air for 5 minute bursts (or whatever is required) and hopefully the license plate vent will maintain cooler temperatures. Really, I wont know how well it works until I do it. Luckily its only what I would call hot here (above 25 C) for one month a year. Most of the time its overcast and rainy.... 7 months out of the year.

Thanks for the tips on those items to control fan speed. I will definitely be looking into those.

One question... if 68 CFM means that the fan has the ability to move 68 cubic feet of air per minute and the van is only 54 square feet, wont that mean that every minute (or less) I'll have 'new' air? I plan to use rain guards on the  driver and passenger doors  and use them as fresh air inlets.

 

[SternWake]

68 square feet is the floor plan. 2 dimensions

Depending on where your wall and a few other factors, it could be about 500 CUBIC feet.

 

[One Awesome Inch]

Thanks for taking the time with all your excellent information.

 

[Canine]

I read this short but accurate info thread thinking, there go I. Same thoughts of a small dash solar, over on a different thread. Same no nonsense answers about lack of power production on the se tiny trickle charging panels. I have the same dread of installing rooftop solar for the loss of stealth. Though I don't park anywhere near my temporary work, I don't like solar that can be seen from the street.

So I read and saw that basically solar is a waste if not a real 100 watt plus panel on the roof. It is what it is fellas and ladies. It's not magic. If you have to drive a little farther daily, and I have to go to a gym to shower every day as well as change sleeping places every night, then increase the awg wire size and let the alternator do its job method will have to work for me as well. I also drive on the weekend for a good 30 minutes to get the stop and go carbon burned off and the fluids up to full operating temps.

I'd like dash solar to work, I really would, but it's impractical. I don't want a 14 inch powered fan on my roof but here in heartland it's going to have to be insta

 

[Canine]

Ugh, had almost a page then fat fingers hit something and poof! No auto save on iPads...

It's just the electronic posting fairy telling me to shorten the reply. Ok.

I was thinking of about the same kind of setup (size)!as the OP and read the great replies. Thanked em' too. I see that dash solar just doesn't work, yet. We need mini solar panels 2.0 for that to work for us. I don't want rooftop solar either, the current hi top can't do it anyway, but the reminder to just increase the wiring from the alternator is a good one.

My situation is different, I drive more (about 30 minutes a day) so my alternator should keep a house battery up. I rv park once a week for laundry and plug in power for my 8 amp battery charger. It's just a good reminder to OP and others that solar isn't as efficient as we hope and ventilation requires something bigger than a computer fan. There are physical laws that can't be broken, and cubic feet per minute means just that, cubic feet.

Anyway, I hope the OP can make it work by parking farther away and driving a bit more. Until he changes jobs or somehow changes his willingness to rooftop solar it (same with me) then we have to accept plan B, which is not what we had hoped for. I don't like getting nicely slapped in the face with reality but this forum does that in a nice and supportive fashion.

Now if I could just get my dr to quit nagging me about my weight and give me an instant weight reduction pill, things would be better, but that's not reality either. It took 10 years to gain this bulk and it won't come off in 10 days, modern advertising not withstanding. That's reality as well.

 

[SternWake]

Glad to be able to help.

The Alternator is not an ideal charging source, as lead acid batteries really want to be back up at true full charge every so many cycles, lets say every 14.

But when the loads are small an the battery not depleted much or rarely under 80% then the 100% recharge every 14 cycles becomes less important. The deeper the discharge cycle the more important the 100% recharge becomes, and the harder it is to achieve.

However One can just resign themselves to replacing the battery more often, rather than go apeshit over trying to achieve perfection in recharging.

Adding a parallel charging circuit to the Original charging circuit helps initial amps the single engine battery can accept, greatly, and the battery seems to respond favorable to high currents even when these high currents are short lived. Thicker copper in a parallel circuit to the engine battery, y is also incredibly beneficial for an Auxiliary battery, in achieving much faster recharges to 80%, and also when cycling 80 to 100% during short drives, when depleting the batteries between those short drives.

Basically fatter copper between alternator and battery allows Absorption voltage to be reached faster( from higher amp flow), and it can also trick the voltage regulator into allowing absorption voltages to be held for LOnger too. It is an adequate amount of time at absorption voltage which fully charges batteries. Long story short, more amps returned to the battery in shorter drives and a happier battery Buying more copper now means buying less lead later.

The more charging sources used whenever possible to return the battery to maximum state of charge will yield best battery life and the best cycle per dollar ratio.

The 80% charged to 100% charged zone is a strange area for the battery and charging sources. Some batteries will do pretty well cycled in this zone, others will complain, and this will change for the worse as the battery ages and loses capacity.

I am trying to get maximum cycle life while also working the batteries hard, as that is where the learning happens, as I am interested in this.

My flooded deep cycle battery is at the end of its life. Specific gravity among all cells varied widely when measured yesterday after a 'full' charge. The cells are using lots of water, more in the last month than in the whole first year, and the levels of all cells were much different. An Equalization charge was ineffective at levelling out specific gravity, and the battery voltage , after refilling, is sagging badly under my normal loading, well under what I expected just last month.

I Am looking into getting a Trojan T-1275 battery, soon, when my USbattery g31 fails. If I can get it to fit, I can expect 50% more cycles from this battery than a Trojan group 31(SCS 225), all factors being equal. I will need to lower my battery tray to accommodate it in the desired location.

I do not require the extra capacity of the T-1275 over the SCS 225, but I want thicker plates and higher electrolyte to Lead ratio of the burlier T-1275.

 

[akrvbob]

Thanks for taking the time with all your excellent information.

When (and if!) I finally grow up, I hope to be half as smart as Sternwake!
Bob

P.S. but I don't want to have his problems with LOCUSTS!

 

[One Awesome Inch]

Yup plan B is likely what I'll have to do. My source of income is just not a typical job, but a career I have invested into with a degree to do it. Its not just a job, but a career. Thats why I have to be very careful about things. Besides, looking on the bright side of things, if I have to park the van a few blocks away to stop from being discovered, it also gives me (one might say forces me) to get much needed exercise.

As to the battery stuff Sternwake was discussing... if my typically daily use does not result in a full charge, how much will the lifespan of the battery be reduced? If a battery lasts 6 years under ideal circumstances and I only get one year, I could life with that as long as my power needs are met.

 

[highdesertranger]

oh no not the locust again. I am curious why having a solar panel ruins your stealth. enlighten me. highdesertranger

 

[SternWake]

You should get a year from the battery with the loads you list and your driving regimen. Hard to really say how the battery is going to respond exactly.

If you can get to an outlet every so often and let a regular battery charger go at it, and restart the charger when it first and secondly indicates full charge, you might get much more.

HDR, I think his place of employment is multistoried with many office windows looking over the parking area, So a Solar panel would be quite obvious even to those with minimal observation skills.

In Such an instance, a cloud of Locust swarming buy would be advantageous for stealth.

 

[SoulRaven]

One Awesome Inch,

I find it curious that you say you're going to be dead broke this summer. Summer is the season when it's usually the easiest to make extra income. Yardwork and curb painting come to mind for quick extra income.

 

[One Awesome Inch]

In the interest of anonymity I can only say so much. Its not that I dont trust the good people on this forum, but after seeing what has happened to some RVers on youtube being harassed by trolls, I believe its better to keep certain things out of the public domain. I will say that almost 40% of my income is going to go to child support starting July.

 

[SoulRaven]

I guess my thought was that with a little planning & work you could avoid being broke in advance. Watch for a thread I'm going to start in a few days, it may be of help.