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DontBeAfraid
Samba Member
Joined: August 09, 2012
Posts: 94
Location: San Franfuckingcisco
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 Posted: Tue Jul 16, 2013 6:16 pm Post subject: Solar Design Idea-140w panel+MPPT+2xTrojan T1xx+TF49+etc? |
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Dear esteemed Sambanistas,
I am leaving for Burning Man in 38 days, and I intend on getting a solar setup functional in my Westy before we leave to go live in the van for 10+ days in the desert.
After many searches here on the samba, reading and re-reading on windsun.com, and after much contemplation, I am asking your advice on my design idea.
I will begin with my goals for this system:
1. The ability to run my imminent TF-49 purchase 24 hours a day for 10+ days. Given my reading on the samba, it is unclear to me whether or not this is a realistic hope, thus I ask you all 
2. The ability to also run my Alpine head unit and Bazooka sub tube for 1-4 hours per day, or some days not at all.
3. The ability to also run LED interior lighting at night sometimes.
Here is the setup I have in my van presently:
-Yandina C100 combiner connecting starter battery and aux Die-Hard Platinum P-2 Deep Cycle 75ah 12v battery under driver seat. (Thank you, BillM, for this thread http://www.thesamba.com/vw/forum/viewtopic.php?t=508148 for walking me through it).
-ProMariner 20amp ProSport gen 2 Battery Charger (3 battery capable) shore charger powered by 110v AC.
-Internal Adjustable Voltage Regulator, per BillM's advice, purchased from this site http://www.davebarton.com/AdjustableVoltage.html that puts out 14.4-14.5 volts with the engine running.
-Stereo, Sink Pump, and Interior Lighting wired to run off aux battery via GW kit.
Here is my design idea that makes the most sense to me after all my research:
-Add 2 Trojan T-105/T-125/T-145s. These two will go under the passenger side of the rear bench and get wired in series to create a 12v system yielding 220-260 aH.
-Add Northern Arizona Wind and Sun Kit:
-One Kyocera KD140SX Solar Module (rated at 7.91 max Amperage output)
-One MidNite Solar Baby Box Enclosure (Not Marine Rated)
-Two 15 Amp DC Circuit Breakers
-One SunSaver 15 Amp MPPT Charge Controller
-Add TF-49 AC/DC model
-Add an inverter to the Trojans to power the TF-49
I understand the TF49 pulls on average about 3 amps per hour, but it will pull more if it is hot in the van. It will be hot in the van in the Nevada desert in August (80s-90s or low 100s during the day).
At this time of year in Nevada, we will be having roughly 13 hour days, so I am planning this system based on full sunlight for the better part of 13 hours every day. This trip is my priority for this system, and it's ok if this is the only location where this setup will work like this.
Question #1: Which of these three batteries is the ideal choice for my needs? Clearly I want to maximize aH, but I hope those before me can clarify why everyone doesn't have the T-145s under their rear bench for the extra 40 aH?
Question #2: Can I leave my Die Hard P-2 under the driver seat and use it exclusively to power the stereo, sink pump, and interior lights, and leave the Trojans to power the TF-49? Are there disadvantages to this?
Question #2.1: If I do keep the P-2 under the driver seat, and add the Trojans under the rear bench, can I use the solar setup to charge all three battery banks-starter, aux#1 (P-2 under driver seat), and aux#2 (2x Trojans under passenger side rear bench)?
Question #3: Can I run another lead from the Yandina to the two Trojans so that they also charge while the van is running?
Question #4: Will the 140watt Kyocera panel (7.91 amps max) and the MPPT controller utilizing 13+/- hours of sun per day produce enough charge to keep the batteries healthy (above %50) and allow me to run the fridge as often as it needs to run at 3 amps average per hour?
Whew. It helps to get it all down on the screen and see what all my thoughts have amounted to. Thank you all for reading through this post, and for offering your advice and experience. I appreciate all your input!
_________________
Dave
1989 Westfalia 2.1 Four-on-the-Floor |
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Altoona
Samba Member
Joined: November 14, 2011
Posts: 505
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| Posted: Tue Jul 16, 2013 6:32 pm Post subject: |
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| The thing that jumped out at me right away was; you do not need an inverter to power the TF. There is more, but that is a start. |
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Phishman068
Samba Member
Joined: February 19, 2007
Posts: 1868
Location: Pittsburgh PA (ish)
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r39o
Samba Polizei
Joined: May 18, 2005
Posts: 9800
Location: San Diego
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| Posted: Tue Jul 16, 2013 7:24 pm Post subject: |
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You need more ummmph.
Add the biggest potable setup you can afford from solarblvd.com
You ewill have the sun so harvest away!
_________________
"Use the SEARCH, Luke" But first visit the Vanagon FAQ!
1990 Multivan EJ 22, Rancho trans 0.82 4th, Small Car front AC, CLKs w/ 215/65-16, homemade big brakes 303mm, Konis, Recaros, etc....
Click to see my ads for Cup holders, Subaru clutch fix and CLK wheels (no wheels currently) |
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joseph928
Samba Member
Joined: September 22, 2011
Posts: 2114
Location: flagstaff az.
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| Posted: Tue Jul 16, 2013 8:38 pm Post subject: solar |
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 I went to No. AZ. wind & sun got the system you are looking at. And a TF-49 DC only, also 2 blue top Optima batteries, well I've used it for a week camping and no problems. Did not have to rum motor at all. Runs all of what you have and my flip down DVD. I don't think I need it but for the hell of it I just added an 85 watt mobile solar panel in the front basket. The rear is the 140. I love the MPPT SunSaver. 
_________________
1987 syncro westy tin top sun roof , GW2.3, rear locker, decoupler, Gary Lee tire rack & winch mount, lift, south african grill, big brakes , rhein alloy ,15 BFG AT, Fiamma 10 foot awning ,140 watt rear 85 watt front solar , mppt, truckfridge, automatic fire extinguishing system, tencent oil cooler, And a RMW SS exhaust! - 1971 bug convertible 1776 engine- 2010 Subaru turbo - 1993 Toyota 4x4 truck - 1999 Harley 95 CI, big bore, Andrews cams . Also 80-84- vans. Stock 65 sunroof bug. |
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nocreditnodebt
Samba Member
Joined: September 28, 2012
Posts: 332
Location: Socal
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| Posted: Tue Jul 16, 2013 8:47 pm Post subject: |
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Thinking you need an inverter just to power an AC/DC fridge speaks volumes. These are designed as 12vdc fridges to run off battery power, and some have a compressor controller which also can handle 120vac making them an AC/DC fridge.
It is debatable whether you even need to drop the extra $$ on an AC DC TF as opposed to just a DC only TF. Your battery charger has enough capacity to power it when you have grid power available. Whether it handles the cycling load of the compressor is another matter. Perhaps someone with the same charger and a compressor fridge can tell you if it will.
Your stereo is an unknown load. 140 watts to power just the fridge, even in the Nevada desert in summertime, is more than enough. It is your other loads which might cause a net daily depletion of your battery bank.
The TF draws about 2.5 amps, only when the compressor is running, and it should run less than 50% of the time even in that heat, unless you are the type who leaves the door open for a minute or two while moving food out and back in.
Use sunshades in the windows to keep the van from turning into an oven and the fridge will use less, and make sure the condenser can breathe well and only refill it with warm beer in the early morning when the warm beer will be at its coolest |
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Timwhy
Samba Member
Joined: January 01, 2009
Posts: 4002
Location: Maine
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teej
Samba Member
Joined: November 26, 2010
Posts: 897
Location: Seattle
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| Posted: Wed Jul 17, 2013 7:14 am Post subject: |
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| Timwhy wrote: |
Everything sounds good, but I too would question the stero and sub. That always seems to be to back breaker
with my aux battery bank (132/AH).
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I have found the same; I added a subwoofer kill switch for use camping if needed. Running 90Ah aux with 65w to 200w solar system depending on which panels are used. Usually take just the 65w.
_________________
1986+ Wolfsburg Weekender Pop-Top 2.3 WBX Manual Trans |
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climberjohn
Samba Member
Joined: January 11, 2005
Posts: 1840
Location: Portland Orygun
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| Posted: Wed Jul 17, 2013 7:48 am Post subject: |
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I agree with many of the above comments.
- No need for an inverter to run the fridge off of AC power. Consider getting the DC only fridge and wiring your aux battery bank directly to it.
- Kill swich for the subwoofer is a good idea. If you need to choose between powering your fridge vs powering your tunes, fridge comes first for most people.
Please report back here after Burning Man and tell us how it went!
-CJ
PS . . .
See this link for BM van camping:
http://www.vwbuscamp.com/
you may want to see this thread:
Taking my Westy to Burning Man
http://www.thesamba.com/vw/forum/viewtopic.php?t=424031
_________________
'86 Westy, 2.5 Subaru power
Know your limits. Exceed them often. |
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Phishman068
Samba Member
Joined: February 19, 2007
Posts: 1868
Location: Pittsburgh PA (ish)
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tiicosyncro
Samba Member
Joined: June 11, 2012
Posts: 93
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| Posted: Wed Jul 17, 2013 8:34 am Post subject: |
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| I would not run an amp or powered sub from the aux batts. Ideally it should be connected to the main and used while driving or engine running. The draw will be too much with other acc for the aux batts. |
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nocreditnodebt
Samba Member
Joined: September 28, 2012
Posts: 332
Location: Socal
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| Posted: Wed Jul 17, 2013 10:25 am Post subject: |
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If the compressor is running near 100% duty cycle in such heat, then the compressor speed should be increased with a resistor in the thermostat circuit.
My Vitrifrigo came with a 277 ohm resistor to run it at 2500 rpm. I removed it for 2000 rpm.
http://www.ra.danfoss.com/TechnicalInfo/Literature...00g402.pdf
Duty cycles which Run the compressor this much is detrimental to its life. Evacuating the heat generated by the condenser/ compressor from compartment is the best way to increase fridge efficiency, decrease battery draw.
http://www.kollmann-marine.com/Fans.aspx#7._Condenser_Cooling_and_process_heat_disposal_Fan_or_fans.
Mine pulls air from the floor below, and exhausts it out a vent behind, with no chance to recycle the pre heated air. I was still well under 50% duty cycle in 95 degree temps a few weeks back, but I have added extra insulation as well.
It is my opinion that most do not have enough compressor/condenser compartment ventilation, especially for summer desert temperatures.
Here is my version of a positive displacement condenser fan. The Fan is a Noctua nf-f12 and draw half the power of the included fan, and has a higher static pressure rating while making less noise. I made a stainless steel shroud for the condenser/compressor compartment, and the 120mm fan pushes air across the whole condenser, then across compressor and controller, rather than a smaller fan pulling air across only a portion of the condenser as the TF's are set up. These fans are quieter pushing rather than pulling air through a restriction
The shroud forces all the floor air through the condenser, across the compressor and controller and is expelled out a vent behind the unit. It cannot pull any preheated air back across the condenser.
The shroud also protects the cooling unit from installation/removal stresses. |
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pushkick
Samba Member
Joined: August 09, 2007
Posts: 1366
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| Posted: Wed Jul 17, 2013 10:38 am Post subject: your setup sounds good |
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the only thing is that if you are using a mppt sunsaver charge controller you can use any solar panel you want and the controller will deal with the higher voltage. so if size doesnt matter why dont you go with the bigger solar panel say a 200-250 watt? they seem to be cheaper per watt than the 140 12volt panels. also remember that depending on the time of year there is only so much sunlight per day lets say 12 hours of sunlight per day its summer. so that gives you 12 hours X 140 watts => 1680 watts/day. in the morning and evening the solar panel output will be less than half the rated output due to angle of sun rays and i didnt figure that into this calc.
the tf-49 uses 60 watts @ 12 volts dc per spec actual may be different. so 60 watts X 24hrs => 1440 watts/day
http://www.truckfridge.com/tf49.html
so you can see that the 140 watt panel will just barely keep up with the tf49 per day without using hardly any battery storage or adding any to the battery. if my calcs are correct. if you use an inverter you will lose at least 15% power in the conversion.
_________________
i see said the blind man to his deaf dog
i am going to quit smoking and drinking and die a healthy man. gotta laugh
there is no deed to the planet earth
1990 vw automatic camper |
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rockfish
Samba Member
Joined: February 13, 2007
Posts: 740
Location: Palo Alto, Calif.
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| Posted: Wed Jul 17, 2013 11:47 am Post subject: |
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I am assuming that you're planning to place some sort of awning on the slider side of your bus. I would recommend a DIY awning (clip to gutter and stake out away from bus by a foot or so --- create some airspace) on the driver's side as well. Anyway that you can diminish the sun directly hitting the windows/metal siding will be much more effective than relying upon window tint and/or insulation. This will be especially helpful if your TF is installed in cabinetry on the driver's side of the bus.
_________________
89 Westy
GW 2.5 5-speed trans
"It's what you learn after you know it all that counts."
- John Wooden |
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r39o
Samba Polizei
Joined: May 18, 2005
Posts: 9800
Location: San Diego
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| Posted: Wed Jul 17, 2013 12:11 pm Post subject: Re: your setup sounds good |
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| Phishman068 wrote: |
The idea of the tf drawing only 2.5ah for only half hour each hour is false in hot conditions. In Nevada it will run nearly non stop.
Window tints and thick curtains will actually affect the fridge operation more than a bigger panel will.
You have to have enough storage capacity to account for clouds and evenings as well. |
AGREE!
Even on the cooler coast of So Cali, my Engel runs a LOT. Even in the shade, with a breese, it runs at a good 70% duty cycle.
In the van, covered with a white towel (not the vents,) it runs almost constantly. Inside temps 80 - 100 when parked. Not 100% sure what it is doing while driving with the AC on, but it is usually on when I stop and open the sliding door.
My measured current draw is 700ma to 2500ma.
| pushkick wrote: |
the only thing is that if you are using a mppt sunsaver charge controller you can use any solar panel you want and the controller will deal with the higher voltage. so if size doesnt matter why dont you go with the bigger solar panel say a 200-250 watt? they seem to be cheaper per watt than the 140 12volt panels. also remember that depending on the time of year there is only so much sunlight per day lets say 12 hours of sunlight per day its summer. so that gives you 12 hours X 140 watts => 1680 watts/day. in the morning and evening the solar panel output will be less than half the rated output due to angle of sun rays and i didnt figure that into this calc.
the tf-49 uses 60 watts @ 12 volts dc per spec actual may be different. so 60 watts X 24hrs => 1440 watts/day
http://www.truckfridge.com/tf49.html
so you can see that the 140 watt panel will just barely keep up with the tf49 per day without using hardly any battery storage or adding any to the battery. if my calcs are correct. if you use an inverter you will lose at least 15% power in the conversion. |
I have come to the conclusion that many folks are overly optimistic about their true power requirements.
I notice most people tend to underestimate the size of PV power needed.
I further notice, they also underestimate the true useful storage capacity of their power store and drain them past the point they can be safely recharged.
In other words they kill batteries. I see this a LOT in RV use where the batteries only last a year. This is especially true for AGM batteries. Kill em dead fast.
To support the above quote, using generally less expensive, higher voltage, grid tie panels in conjugation with an MPPT controller will maximize your PV yield.
Add to that a storage system that is at least double what you guess you need.
This way you have a fighting chance at staying reliablely off grid for extended periods of time.
Later topping off the batteries via the engine or a stand alone smart charger has many benefits when you can.
In other words, if you want brainless reliable operation, go large!
Have fun!
_________________
"Use the SEARCH, Luke" But first visit the Vanagon FAQ!
1990 Multivan EJ 22, Rancho trans 0.82 4th, Small Car front AC, CLKs w/ 215/65-16, homemade big brakes 303mm, Konis, Recaros, etc....
Click to see my ads for Cup holders, Subaru clutch fix and CLK wheels (no wheels currently) |
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joseph928
Samba Member
Joined: September 22, 2011
Posts: 2114
Location: flagstaff az.
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| Posted: Wed Jul 17, 2013 2:42 pm Post subject: TF-49 |
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Don't know why nobody has address this, but when I put in my TF-49 I added more insulation on it. Then the old vent on the westy fridg. modified it to pull air over the compressor put in a computer fan and a switch. On a hot day sun out have solar turn the fan on, and the compressor runs a lot less! Seems you have a hole and vent why not use it for some good.
_________________
1987 syncro westy tin top sun roof , GW2.3, rear locker, decoupler, Gary Lee tire rack & winch mount, lift, south african grill, big brakes , rhein alloy ,15 BFG AT, Fiamma 10 foot awning ,140 watt rear 85 watt front solar , mppt, truckfridge, automatic fire extinguishing system, tencent oil cooler, And a RMW SS exhaust! - 1971 bug convertible 1776 engine- 2010 Subaru turbo - 1993 Toyota 4x4 truck - 1999 Harley 95 CI, big bore, Andrews cams . Also 80-84- vans. Stock 65 sunroof bug. |
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PDXWesty
Samba Member
Joined: April 11, 2006
Posts: 6247
Location: Portland OR
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| Posted: Wed Jul 17, 2013 6:08 pm Post subject: |
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I had very similar needs to yours. I wanted to have three battery banks dedicated to different uses: starting, auxilliary, stereo, sub, etc. I built a battery control panel to control everything. I used two Yandinas so that batteries could be combined or seperated using switches. I also set it up so I could direct the solar charge to whichever battery I wanted so I could charge the lowest battery first. If one bank is low, I can force combine a yandina and direct power where I need too. You can connect everything through one Yandina, but it may slow the charging using the alternator.
I suggest you set things up the way you suggest, but keep the output from your solar panel flexible. Use battery clips so you can hook the charge directly to whatever battery you want or need to. For me, the sub was the most important part of the system!
And I also think you should run the fridge on DC. The inverter will eat more power.
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whynotvw
Samba Member
Joined: May 04, 2004
Posts: 1322
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| Posted: Wed Jul 17, 2013 10:56 pm Post subject: |
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May consider carrying a small inverter/generator to solve your issues.
I wanted similar outcome as the OP posted. But couldn't achieve it with the solar panel. (currently have 80 watt)
I carry Honda eu1000 with Iota dls 30 amp charger. Takes approx. two hours to top off my 2 trojan 6volt batteries.
Last edited by whynotvw on Thu Jul 18, 2013 6:40 am; edited 1 time in total |
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alain riaud
Samba Member
Joined: October 13, 2011
Posts: 172
Location: France
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| Posted: Thu Jul 18, 2013 12:51 am Post subject: |
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I have a Kyocera 140Wp/ Non MPPT controller and 85AH battery based system on my van for the sole use of an Engel fridge draming 2.5A max
It's new, still observing and I will tell more later.
One thing I can says right now, based on my solar static system on my house:
Don't expect more than 5 / 6 hours of production in optimal (100% sunny) conditions in summer. 140*5 --> 700Wh per day, this because your panel is horizontal (not optimal) and morning and evenin power is less ( solar rays not normal to the panels) |
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pushkick
Samba Member
Joined: August 09, 2007
Posts: 1366
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| Posted: Thu Jul 18, 2013 5:14 am Post subject: solar help |
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i think i did some calcs on another thread and the solar wattage that is needed just for the frig is around 350-400 watts if you want to run 24/7. this is based on actual reading from 140watt panel and a moningstar controller.
_________________
i see said the blind man to his deaf dog
i am going to quit smoking and drinking and die a healthy man. gotta laugh
there is no deed to the planet earth
1990 vw automatic camper |
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