solar pannels ??

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kaylin640

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Location
oregon
Found this blog while surfing the web on boondocking and have questions about it.
I for warn its a long read but if you havent already seen this and boondock full time with solar Please glance at it and let me know what you think.
Having never had a 5th wheel of my own or solar pannels making sure its done right the first time is a plus...

http://handybobsolar.wordpress.com/the-rv-battery-charging-puzzle-2/

any help would be great
thanks
 
Here is some more excellent reading on installing solar.

http://www.jackdanmayer.com/rv_electrical_and_solar.htm

Paul
 
Lots of good reading there..... I have used solar since 1984 on my sailboat. I've always had solar on my campers at a smaller scale because demand is less.

A few comments.......

MPPT controllers are over-rated in my opinion. I have run tests on identical systems parked next to each other. The MPPT controller increased output amperage to the battery at a consistent 10% higher rate. Figuring the price of the MPPT controller over a std PWM controller you can buy a lot more solar panel for the same amount of money (if you have the space).

Another remark is attachment of the solar panel mounting brackets. There is no reason to drill holes in the roof anymore. 3M has developed a VHB double sided tape the will securely fasten the mounting brackets to all but a rubber roof (I just don't know about the rubber roof). Trust me..... this stuff WILL NOT let go. I had it on my travel trailer for 2-years. I just removed the brackets and I had to use a special blade on a multi-tool to cut through the tape without ripping a hole in the aluminum roof.
 
Wavery said:
Another remark is attachment of the solar panel mounting brackets. There is no reason to drill holes in the roof anymore. 3M has developed a VHB double sided tape the will securely fasten the mounting brackets to all but a rubber roof (I just don't know about the rubber roof). Trust me..... this stuff WILL NOT let go. I had it on my travel trailer for 2-years. I just removed the brackets and I had to use a special blade on a multi-tool to cut through the tape without ripping a hole in the aluminum roof.

The problem with the rubber roof is not the tape but how well the rubber is bonded to the underlayment.  Big issue there as far as I am concerned.
 
Jim Godward said:
The problem with the rubber roof is not the tape but how well the rubber is bonded to the underlayment.  Big issue there as far as I am concerned.
That's what I was thinking....... :eek:
 
I used VHB tape to mount a solar panel on my MH 8 years and it is still up on the roof. Hope it never comes off.

George
 
cvrvr said:
I used VHB tape to mount a solar panel on my MH 8 years and it is still up on the roof. Hope it never comes off.

George
I hope that you never have to take it off.....it's a PITA....... at least you don't have holes in your roof though..... ;)
 
I had a long talk with a 3M engineer concerning using VHB tape (and by the way there are different types) and for this to work there needs to be enough surface area for there to be sufficient grip/holding. There is a formula for figuring that out which takes into account wind load... The mounts I have were imported by me from China and have a rather broad ABS plastic contact patch. Z mounts do not have enough. You could however make ones using aluminum angle that does have enough area.
 
Shadow Catcher said:
I had a long talk with a 3M engineer concerning using VHB tape (and by the way there are different types) and for this to work there needs to be enough surface area for there to be sufficient grip/holding. There is a formula for figuring that out which takes into account wind load... The mounts I have were imported by me from China and have a rather broad ABS plastic contact patch. Z mounts do not have enough. You could however make ones using aluminum angle that does have enough area.
I made my mounting brackets out of 3" x 36" door sill plates from H/D cut in 4" lengths forming an "L", 3" high x 1" wide x 4" long.... they are high tensile aluminum and you can cut them to any length that you want. I pop-riveted the brkts to the solar panel and used the VHB tape to adhere them to the roof.

I used 3M 4910..... tensile strength is 100# per sq inch. Each bracket was 4" long x 4 brkts = 1600# total tensile strength.

Trust me, I could have made each brkt 1.5" long and those suckers weren't coming off in a tornado much less 100mph wind over the roof.

Scroll down to pg 4 & 5 to see the holding power of this stuff. It is unbelievable........ but true.
http://multimedia.3m.com/mws/mediawebserver?mwsId=66666UF6EVsSyXTtnxMtLXs6EVtQEVs6EVs6EVs6E666666--&fn=70070938637.pdf
 

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Hi all,

Here is a simple flow chart.

Budget-->Energy Audit-->Battery bank size-->number of watts-->PWM or MPPT.

Here is a link to the rather special spreadsheet that N8GS has created to help size solar battery charging systems!
Solar Spread Sheet N8GS
 
Wavery said:
I made my mounting brackets out of 3" x 36" door sill plates from H/D cut in 4" lengths forming an "L", 3" high x 1" wide x 4" long.... they are high tensile aluminum and you can cut them to any length that you want. I pop-riveted the brkts to the solar panel and used the VHB tape to adhere them to the roof.

I used 3M 4910..... tensile strength is 100# per sq inch. Each bracket was 4" long x 4 brkts = 1600# total tensile strength.

Trust me, I could have made each brkt 1.5" long and those suckers weren't coming off in a tornado much less 100mph wind over the roof.

Scroll down to pg 4 & 5 to see the holding power of this stuff. It is unbelievable........ but true.
http://multimedia.3m.com/mws/mediawebserver?mwsId=66666UF6EVsSyXTtnxMtLXs6EVtQEVs6EVs6EVs6E666666--&fn=70070938637.pdf

I mounted these panels last week. After sitting for a few days I went up and pulled up on the ends of the solar panels hard enough to almost bend the frame. There is NO WAY those are coming off. That 3M VHB (pt# 4941) tape is amazing stuff.

Now all I have to do is replace that hatch over the bathroom..... ;D
 

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Wavery said:
I made my mounting brackets out of 3" x 36" door sill plates from H/D cut in 4" lengths forming an "L", 3" high x 1" wide x 4" long.... they are high tensile aluminum and you can cut them to any length that you want. I pop-riveted the brkts to the solar panel and used the VHB tape to adhere them to the roof.

I used 3M 4941..... tensile strength is 100# per sq inch. Each bracket was 4" long x 4 brkts = 1600# total tensile strength.

Trust me, I could have made each brkt 1.5" long and those suckers weren't coming off in a tornado much less 100mph wind over the roof.

Scroll down to pg 4 & 5 to see the holding power of this stuff. It is unbelievable........ but true.
http://multimedia.3m.com/mws/mediawebserver?mwsId=66666UF6EVsSyXTtnxMtLXs6EVtQEVs6EVs6EVs6E666666--&fn=70070938637.pdf
 

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