Home » Public Forums » GMCnet » Harbor Freight 45 watt solar "system" (Some observations)
Harbor Freight 45 watt solar "system" [message #103824] |
Fri, 22 October 2010 17:16 |
idrob
Messages: 645 Registered: January 2005 Location: Central Idaho
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I have played with and built a number of Solar Systems for 15 years now and in general recommend using high quality well built parts, such as panels and charge controllers. I also recommend using panels made with crystalline technology rather than amorphous technology, as they are twice as efficient per unit area.
In the past year, Costco, Fry's electronics, and Harbor Freight have all been selling "Solar Systems" consisting of 3 or 4 amorphous panels with a total of around 45 to 50 watts capacity. They may have a charge controller and inverter, you supply the battery. Cost has been in the $250 to $350 range.
The ones I have looked at were generally poorly made, plastic framed and not impressive at all, vs. higher quality systems that are available.
However, recently I was in Harbor Freight and saw that their "45 watt solar system" was running on a coupon sale for $150. I inspected it in the store and was reasonably impressed with the panels, which are well made and framed in aluminum, not plastic. They are the amorphous type, so the output is not very high for the area, but at least they are well made.
The kit comes with 3 panels, a flimsy rack to hold them, a charge controller that regulates the charge to a 12 volt battery (which you must supply) and a set of outlets for power: one cigaret lighter outlet, a USB outlet, a 3 volt, 6 volt and 9 volt outlet, a pair of 12 volt phone plug outlets with a set of 12 volt compact fluorescent lights that can be plugged in to them. It does not have a 120 volt inverter.
I decided to buy one to play with. The panels are quite well made, as noted above. The output is roughly what is specified, not a lot, but something to start with. The little 12 volt compact fluorescent screw base lights are cute. The converter box, with digital voltage readout is reasonably well made. The charge wires to hook up to a 12 volt battery are flimsy and not much.
So, if you want to play with a little solar for not much money, this HF unit is not too bad a place to start. If you had a GMC that sat in storage you could put the panels inside the windshield and use it to keep the batteries charged when not in use.
It is not a great system, but for the money, not too bad. I liked the panel quality. It would make a good little system for a garden shed with no power, the lights included are kind of cute.
This is not a serious system for rooftop mounting on your rig, as the power output is too little. My recommendation for a useful GMC system would be for a 120 + watt panel and good charge controller at the minumum. But if you want to play, it is kinda neat. Just don't expect a huge "free solar" source or to be able to get rid of your Onan. LOL.
Rob Allen
former owner of '76 x-PB
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better system [message #103851 is a reply to message #103824] |
Fri, 22 October 2010 22:12 |
bukzin
Messages: 840 Registered: April 2004 Location: North California
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Rob,
If I did want a better system (better suited for dry camping)
which suppliers do you like and approx. money
for a basic set-up?
Thanks
Bukzin
1977 Palm Beach
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Re: [GMCnet] Harbor Freight 45 watt solar "system" [message #103858 is a reply to message #103840] |
Fri, 22 October 2010 23:13 |
idrob
Messages: 645 Registered: January 2005 Location: Central Idaho
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ljdavick wrote on Fri, 22 October 2010 17:36 | Rob,
Is there any risk of boiling the batteries if this is connected to a rig that is left in storage? I have a Progressive Dynamics charger with its miracle float wizard technology thingy and had thought that any solar system I installed would pass through it.
Am I over complicating the issue?
Larry Davick
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Larry: The "box" which comes with the Harbor Freight system is supposed to have a built in charge controller in it, limiting the charge rate and final voltage. I don't know the quality of that at this point, but think it would be ok to use, and not cause any undo battery overcharging. If in doubt, I would only hook up one of the three panels for long term "keep charged" use, that would limit the current to only about one amp maximum.
This unit and system would be connected in parallel to your PD converter/charger and NOT wired through it. The PD and charge wizard are a system unto themselves, and cannot be used as a charge regulator for other charge sources such as a solar system.
Rob Allen
former owner of '76 x-PB
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Re: better system [message #103861 is a reply to message #103851] |
Fri, 22 October 2010 23:35 |
idrob
Messages: 645 Registered: January 2005 Location: Central Idaho
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bukzin wrote on Fri, 22 October 2010 20:12 | Rob,
If I did want a better system (better suited for dry camping)
which suppliers do you like and approx. money
for a basic set-up?
Thanks
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Right now I like the stock, and prices from
http://www.ecodirect.com/
Best stuff right now seems to be:
The Sharp 130 Watt Solar Panel 12 Volt > ND-130UJF which at $436 is an excellent buy. Or you might chose a Kyocera 135 Watt Solar Panel 12 Volt > KD135GX-LPU for $461, also a good deal. Note that these single panels have about three times the capacity of the three panel HF units. Of course they are physically larger but not the size of 9 HF panels.
For a quality charge controller at a moderate price I favor a Xantrex C35 3-Stage PWM Charge Controller 35 Amp, 12/24 Volt for $86.25. It is an excellent charge controller with lots of capacity for expansion of your panels if you went to additional ones. I have used it on half a dozen different solar systems that I have built as a volunteer for the National Forest Service.
I have not ordered from ecodirect, but they cary all the good quality stuff and their prices are excellent.
I have no affiliation with them, or any of the solar manufactures or retailers. I do know these things are all quality units which will not let you down, and will last for at least 20 years.
All you would need in addition to the above would be the mounting brackets and wire to run from the panel to your charge controller and on to your house batteries.
Hope that helps you some.
Rob Allen
former owner of '76 x-PB
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Re: [GMCnet] Harbor Freight 45 watt solar "system" [message #103865 is a reply to message #103858] |
Sat, 23 October 2010 00:28 |
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ljdavick
Messages: 3548 Registered: March 2007 Location: Fremont, CA
Karma: -3
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Thank you, Rob.
Larry Davick
On Oct 22, 2010, at 9:13 PM, Rob Allen <profmail@wildblue.net> wrote:
>
>
> ljdavick wrote on Fri, 22 October 2010 17:36
>> Rob,
>>
>> Is there any risk of boiling the batteries if this is connected to a rig that is left in storage? I have a Progressive Dynamics charger with its miracle float wizard technology thingy and had thought that any solar system I installed would pass through it.
>>
>> Am I over complicating the issue?
>>
>> Larry Davick
>
>
> Larry: The "box" which comes with the Harbor Freight system is supposed to have a built in charge controller in it, limiting the charge rate and final voltage. I don't know the quality of that at this point, but think it would be ok to use, and not cause any undo battery overcharging. If in doubt, I would only hook up one of the three panels for long term "keep charged" use, that would limit the current to only about one amp maximum.
>
> This unit and system would be connected in parallel to your PD converter/charger and NOT wired through it. The PD and charge wizard are a system unto themselves, and cannot be used as a charge regulator for other charge sources such as a solar system.
>
>
>
> --
> Rob Allen
> former owner of '76 x-PB
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
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Larry Davick
A Mystery Machine
1976(ish) Palm Beach
Fremont, Ca
Howell EFI + EBL + Electronic Dizzy
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Re: Harbor Freight 45 watt solar "system" [message #103868 is a reply to message #103867] |
Sat, 23 October 2010 01:28 |
idrob
Messages: 645 Registered: January 2005 Location: Central Idaho
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Duce Apocalypse wrote on Fri, 22 October 2010 22:51 | What is the largest wattage single pannel that one can mount?
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I don't think the 12 volt ones come much larger than 150 watts now, the higher wattage ones are now 24 or higher volts.
Physically of course, depends on your real estate.
Rob Allen
former owner of '76 x-PB
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Re: Harbor Freight 45 watt solar "system" [message #103978 is a reply to message #103824] |
Sun, 24 October 2010 09:54 |
tgeiger
Messages: 518 Registered: February 2006 Location: kansas city
Karma: -1
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Rob,
If a guy was going to consider doing this, would this system support a electric refrig? I have the AC/DC refrig in mine, which works great, and I was wondering if this system would support that? I have 2 Trojan golf cart batteries running the house electrical needs.
Also I checked out the site and saw some panels for a little bit more that would get into the 180 watt range with 24 volts. Would that be a bit better?
Tom Geiger
76 Eleganza II
KCMO
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Re: Harbor Freight 45 watt solar "system" [message #104002 is a reply to message #103978] |
Sun, 24 October 2010 12:01 |
idrob
Messages: 645 Registered: January 2005 Location: Central Idaho
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tgeiger wrote on Sun, 24 October 2010 07:54 | Rob,
If a guy was going to consider doing this, would this system support a electric refrig? I have the AC/DC refrig in mine, which works great, and I was wondering if this system would support that? I have 2 Trojan golf cart batteries running the house electrical needs.
Also I checked out the site and saw some panels for a little bit more that would get into the 180 watt range with 24 volts. Would that be a bit better?
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Stick with 12 volt panels, you don't want to go to a 24 volt system.
The original refrigerator, with original power supply probably averages about 50 watts per hour to run. This can be reduced some, maybe down to 30 to 35 watts, but lets stick with the 50 watt consumption for the calculations. A 130 watt panel will, after the conversion efficiencies to battery and back, probably actually produce 100 real watts per hour on a sunny day. Lets assume a 5 hour sun day, so the panel would put out 500 watt hours, and the refrigerator over 24 hours would require 50 x 24 = 1200 watt hours. The batteries could supplement for a while, so this would extend your stay, but not make you self sufficient for a long period of time. However, with some short generator run time and a good PD converter/charger, it would help a lot.
Two of these 130 watt panels would come closer to the refrigerator requirements. You can play with the figures and do the math to see what might work for your situation.
Some information on the original Norcold 12/120 volt refrigerator and some possible modifications are in this article I put together some time ago:
http://www.bdub.net/Refrigeration_in_the_GMC.pdf
Hope this all helps you.
Rob Allen
former owner of '76 x-PB
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Re: [GMCnet] Harbor Freight 45 watt solar "system" [message #104007 is a reply to message #104002] |
Sun, 24 October 2010 12:27 |
jayrabe
Messages: 509 Registered: June 2009 Location: Portland, OR
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Rob, why do you recommend not doing 24v? 24v gives less amps and less voltage drop and also maybe smaller wires, so what's the drawback?
Thanks
J
76 PB
Portland, OR
> To: gmclist@temp.gmcnet.org
> From: profmail@wildblue.net
> Date: Sun, 24 Oct 2010 12:01:41 -0500
> Subject: Re: [GMCnet] Harbor Freight 45 watt solar "system"
>
>
>
> tgeiger wrote on Sun, 24 October 2010 07:54
> > Rob,
> >
> > If a guy was going to consider doing this, would this system support a electric refrig? I have the AC/DC refrig in mine, which works great, and I was wondering if this system would support that? I have 2 Trojan golf cart batteries running the house electrical needs.
> > Also I checked out the site and saw some panels for a little bit more that would get into the 180 watt range with 24 volts. Would that be a bit better?
>
>
> Stick with 12 volt panels, you don't want to go to a 24 volt system.
>
> The original refrigerator, with original power supply probably averages about 50 watts per hour to run. This can be reduced some, maybe down to 30 to 35 watts, but lets stick with the 50 watt consumption for the calculations. A 130 watt panel will, after the conversion efficiencies to battery and back, probably actually produce 100 real watts per hour on a sunny day. Lets assume a 5 hour sun day, so the panel would put out 500 watt hours, and the refrigerator over 24 hours would require 50 x 24 = 1200 watt hours. The batteries could supplement for a while, so this would extend your stay, but not make you self sufficient for a long period of time. However, with some short generator run time and a good PD converter/charger, it would help a lot.
>
> Two of these 130 watt panels would come closer to the refrigerator requirements. You can play with the figures and do the math to see what might work for your situation.
>
> Some information on the original Norcold 12/120 volt refrigerator and some possible modifications are in this article I put together some time ago:
>
> http://www.bdub.net/Refrigeration_in_the_GMC.pdf
>
> Hope this all helps you.
>
> --
> Rob Allen
> former owner of '76 x-PB
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
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Re: [GMCnet] Harbor Freight 45 watt solar "system" [message #104015 is a reply to message #104007] |
Sun, 24 October 2010 13:21 |
idrob
Messages: 645 Registered: January 2005 Location: Central Idaho
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jayrabe wrote on Sun, 24 October 2010 10:27 |
Rob, why do you recommend not doing 24v? 24v gives less amps and less voltage drop and also maybe smaller wires, so what's the drawback?
Thanks
J
76 PB
Portland, OR
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Everything else in your coach is 12 volts and there is no convenient or simple way to convert a 24 volt panel to charge a 12 volt battery system.
Rob Allen
former owner of '76 x-PB
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Re: [GMCnet] Harbor Freight 45 watt solar "system" [message #104032 is a reply to message #104027] |
Sun, 24 October 2010 15:18 |
idrob
Messages: 645 Registered: January 2005 Location: Central Idaho
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ljdavick wrote on Sun, 24 October 2010 12:14 | In my Sunday paper there is a flyer for Harbor Freight with a coupon for the 45 watt solar panel kit for $149.99. Of interest to some is the "GMC Tool" coupon for $29.99 and a small 800 watt generator for $89.99. Anybody want a 3,000 lb winch for $49.99, or a 3,000 lb aluminum "racing" jack for 59.99? They have a 1/2" torque wrench for $9.99 and a 1500 watt heat gun for $7.99.
My Sunday paper has just become very expensive...
Larry Davick
The Mystery Machine
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On the GMC tool, wait until the "after thanksgiving sale coupons" The price with a coupon drops for 3 days only to $19.95
Rob Allen
former owner of '76 x-PB
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Re: [GMCnet] Harbor Freight 45 watt solar "system" [message #104036 is a reply to message #104032] |
Sun, 24 October 2010 16:15 |
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ljdavick
Messages: 3548 Registered: March 2007 Location: Fremont, CA
Karma: -3
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Senior Member |
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Ha! And I was just about out the door to buy it. You've saved me ten bucks!
Sent from my iPad
On Oct 24, 2010, at 1:18 PM, Rob Allen <profmail@wildblue.net> wrote:
>
>
> ljdavick wrote on Sun, 24 October 2010 12:14
>> In my Sunday paper there is a flyer for Harbor Freight with a coupon for the 45 watt solar panel kit for $149.99. Of interest to some is the "GMC Tool" coupon for $29.99 and a small 800 watt generator for $89.99. Anybody want a 3,000 lb winch for $49.99, or a 3,000 lb aluminum "racing" jack for 59.99? They have a 1/2" torque wrench for $9.99 and a 1500 watt heat gun for $7.99.
>>
>> My Sunday paper has just become very expensive...
>>
>> Larry Davick
>> The Mystery Machine
>
>
> On the GMC tool, wait until the "after thanksgiving sale coupons" The price with a coupon drops for 3 days only to $19.95
>
> --
> Rob Allen
> former owner of '76 x-PB
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Larry Davick
A Mystery Machine
1976(ish) Palm Beach
Fremont, Ca
Howell EFI + EBL + Electronic Dizzy
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Re: [GMCnet] Harbor Freight 45 watt solar "system" [message #104064 is a reply to message #104057] |
Sun, 24 October 2010 19:45 |
idrob
Messages: 645 Registered: January 2005 Location: Central Idaho
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Dennis S wrote on Sun, 24 October 2010 17:05 |
Where do you find the coupon for the $19.95 multifunction tool?
Dennis
Dennis Sexton
73 GMC
Germantown, TN
USA
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I found mine on a table inside the HF store in Missoula MT. Seems a bit early for the "three day sale" flyer to be out, but there it was.
Rob Allen
former owner of '76 x-PB
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Re: [GMCnet] Harbor Freight 45 watt solar "system" [message #104088 is a reply to message #103978] |
Mon, 25 October 2010 00:30 |
robert caudle
Messages: 25 Registered: January 2004
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Junior Member |
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there is a blog available that tells you pretty well all about solar and the
considerations you need.....just google
"handybob"
----- Original Message -----
From: "tom geiger" <tgeiger@burnsmcd.com>
To: <gmclist@temp.gmcnet.org>
Sent: Sunday, October 24, 2010 9:54 AM
Subject: Re: [GMCnet] Harbor Freight 45 watt solar "system"
>
>
> Rob,
>
> If a guy was going to consider doing this, would this system support a
> electric refrig? I have the AC/DC refrig in mine, which works great,
> and I was wondering if this system would support that? I have 2 Trojan
> golf cart batteries running the house electrical needs.
> Also I checked out the site and saw some panels for a little bit more that
> would get into the 180 watt range with 24 volts. Would that be a bit
> better?
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
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