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DIY Solar/Trimetric/6 Volts on a 2015 Grandby


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#21 carld

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Posted 06 February 2016 - 08:17 PM

I may have overstated it a bit about the battery limiting the current, although it does decline and the battery approaches 100%, and it will help to add more solar power.   This is way overkill but it is an interesting subject to me so here goes.  Here in Plano TX the cities website shows the solar power W/sqm for each day.  About now it's peaking around 680 W/sqm at solar noon, 12:40 pm.   For today sun rise and sun set are 5.37 hrs before and after solar noon.   Using a power curve y=680 x abs(Kt)^p curve, I found K and p to approximate the solar power for a sunny day here.  I then did the same to approximate the solar elevation angle for today, here in Plano it reaches 41.2 deg at solar noon.  I projected this solar energy onto a horizontal (flat roof mount) solar panel and multiplied that by the effective solar panel area for 2 100 W panels to get solar panel watts.  

 

The camper load is different at different times of the day so the second section finds the camper load each hour for one day. The difference (solar panel watts- camper load) is the available battery current.  Starting with a 100% battery charge at sunset, limited the battery current to 0.5 amps if the battery is more than 80% charged and found the % charge for the battery.  Day after day the ending % charge is copied to the new day % start.  The first screen shot is for 200 W panels (Solar panel watts multiplier =2) and 200 Amp hr Battery. The second shot is for 300 W panels and 200 Amp hr. 

 

 

In Portland Oregon the solar elevation angle is 12 deg less, the solar intensity is about half, 341 w/sqm, and the solar day is slightly longer 5.82 hr. 

 

It appears that I overestimated the Load.  I have it at 72 amp hr so things should look a lot better at 50 amp hr.

Attached Thumbnails

  • Solar Model 200W 200AH.jpg
  • Solar Model 300W 200AH.jpg

Edited by carld, 06 February 2016 - 08:28 PM.

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2002 Tundra AC 4x4 with 2015 Ocelot

2006 Tundra AC 4x4 with 2018 78" Ocelot

2011 Tundra AC 4x4 with 2010 78" Ocelot

 

 


#22 Wallowa

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Posted 06 February 2016 - 09:32 PM

Carl,

 

OK...I now have a headache trying to pull the charts apart so that I could understand them.  You did one hell of a lot of work!

 

Are there Cliff Notes?

 

"-12" is 2400 hrs?

 

The amount of amps used by the various on-board systems was particularly helpful to me...thanks.

 

Phil


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#23 DrJ

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Posted 06 February 2016 - 10:24 PM

The simple answer is that solar recharging of your batteries is based on many factors including angle of the sun, solar day light hours, tilting the panels, type of charge controller, amount of consumption during the day, size of your batteries, etc...

Campers collecting sun in Texas have a totally difference experience than say Washington because of sunlight, clouds, trees, etc...

The newer system for FWC is 150 watt panel and like around 150 amps of battery power. This is propably adequate for most people. But I wanted something more because I don't have the same solar hours where I live. So I need to collect more power on a daily basis than someone who lives further south.

There is a limitation on all things including battery power. It turns out 2 6 volt AGMs fit perfect in the battery compartment in my front dinette model. A larger battery was not possible unless I wanted to remodel the cabinet or use the space the front dinette, which I didn't.

Everyone's setup is slightly different so you can adjust it however you want to fit your needs. Mine works great and I've been very happy with it.

My favorite test is the ice cream test. If my ice cream is still cold in my freezer at the end of the day I'm a happy guy.
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#24 Wallowa

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Posted 07 February 2016 - 12:29 AM

Dr J,

 

Got the concept of the variables impinging on the solar panel power production.  What is a TBA for us is with the FWC 160 W mounted and 80W portable and their two battery set-up will we be able to keep up with our demand under differing environmental conditions and of course so many factors play into that.

 

As a corollary; am I correct in believing that the Tundra alternator will charge the truck battery AND the two Hawk batteries? 

 

There was some discussion that a FWC owner is not seeing his camper batteries being charged via the truck alternator.

 

Carl's charts clearly point to the power consumers and gives us the means to slow down the power draw by shutting down or lessening specific high power uses.

 

Thanks for all the input; it really helps us.

 

Phil


Edited by Wallowa, 07 February 2016 - 12:31 AM.

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#25 carld

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Posted 07 February 2016 - 01:03 AM

Sorry, I told you I went overboard.  A second look reduces the load by 30% and it looks good.  Also if you add your portable solar on cloudy days it  helps a  lot especially if they are directed and out of the shade during sunlight hours..  With 200 Amp Hr your good for two or three days.  Your initial assumptions look good.   Just don't go to Alaska and leave the fridge going. 


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2002 Tundra AC 4x4 with 2015 Ocelot

2006 Tundra AC 4x4 with 2018 78" Ocelot

2011 Tundra AC 4x4 with 2010 78" Ocelot

 

 


#26 DonC

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Posted 07 February 2016 - 04:29 AM

"There was some discussion that a FWC owner is not seeing his camper batteries being charged via the truck alternator."

 

I am at least one of those owners.  I have a 2006 Tundra with a Fleet and 2 camper batteries.  I get zero amps of charging and was told by FWC to not expect any significant charging from the truck, yet I read here of people getting 15 amps/hr.

 

My truck/camper has been checked by FWC, multiple times to my local dealer, and a local battery/alternator shop.  I'm at a loss of where to go next.  Even with my solar system, one/two days of cloudy weather and my batteries are dead given no charging from the truck.  


Edited by DonC, 07 February 2016 - 04:33 AM.

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#27 pvstoy

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Posted 07 February 2016 - 05:35 AM

This is a long story but there is good information had here charging batteries with different inputs.

http://roadslesstrav...er-shore-power/

And one from the Expo portal
http://www.expeditio...-simultaneously

Edited by pvstoy, 07 February 2016 - 05:56 AM.

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#28 DrJ

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Posted 07 February 2016 - 05:37 AM

Don,

I am sorry about your issues with your system. That must be very frustrating. One of the biggest problems is that so few services are available for RV people who want to learn solar and off grid power mangement. There is no one within hundreds of miles from where I live to do that. I had to learn much of it myself from studying on line. I'm still learning more all the time.

I am not sure why your system does not work.

When I wired my toy hauler with a solar system and an inverter, I hired an electrician to help me do some of the AC wiring. Maybe you need an electrician to look at your system? Sounds like you've tried everything else reasonable to this point.

When it is connected correctly, I can definitely verify that there is power coming from the truck alternator to my camper batteries. I have certainly had 10-15 amps on a regular basis before.
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#29 DonC

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Posted 07 February 2016 - 03:18 PM

Dr J - will a regular electrician understand all these 12V components?  I always figured it would take a 12V/RV or perhaps an auto tech person to understand the battery wiring, battery separator, alternator interactions, etc.  Maybe there is still something wired incorrectly, but like I said, it was shipped to FWC once, and the local distributor has had it 3 times in an attempt to diagnose my on-going electrical issues.  

 

I finally got the solar right with the help of this forum, including your support, so that's good.  Turns out some of that was simply bad Renogy  flexible panels which it seems most people have moved away from now.  But no matter how much solar you have you can't store any more energy than your battery capacity, so a few cloudy days are trouble, and charging from the truck is important.


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#30 Wallowa

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Posted 07 February 2016 - 04:12 PM

My question still is:

 

Does FWC installation with solar or without provide for charging of camper batteries from the truck alternator?  Factory not after purchase.

 

Not can it be wired to provide this, but does FWC wire the camper and truck connection to provide the charging of the batteries via the truck alternator?

 

Thanks,

 

Phil


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