Author Topic: Harbor Freight 45 Watt Solar Panel Kit  (Read 21611 times)

Offline Pathman

  • Survivor
  • ***
  • Posts: 113
  • Karma: 2
Harbor Freight 45 Watt Solar Panel Kit
« on: June 13, 2010, 03:18:04 PM »
I have a coupon for this setting the prince at $159.99.  Not sure if that is a good price but what all can a simple 45 watt solar panel run?

It would still need both 12 volt storage battery and 300 watt power inverter on top of this.  Here's the specs from their web site that is selling the panel kit at $199.

Three 15 watt solar panels generate plenty of clean, quiet energy, using solar energy from the sun to run TVs, lights, computers, even recharge 12 volt DC batteries. Simply connect the solar panels to your own 12 volt DC storage battery, and then use at least a 300 watt power inverter (not included) to power your 120 volt AC appliances anywhere.

    * Weatherproof solar power center works under all light conditions
    * Includes 3, 6, 9 and 12 volt DC adapter outlets
    * Easy-to-read LED charge indicator
    * Includes mounting hardware, lights, 12 volt DC socket and battery clamps

Requires 12 volt storage battery and 300 watt power inverter (not included).
Maximum current: 3000 mA
15 watts max per panel
Peak voltage: 23.57 volts open current
Panel dimensions: 12.40" x 36.42" x 0.75" each


Anything the mind can conceive and believe, it can achieve. Napoleon Hill

Offline fred.greek

  • Survivalist Mentor
  • *****
  • Posts: 631
  • Karma: 29
Re: Harbor Freight 45 Watt Solar Panel Kit
« Reply #1 on: June 13, 2010, 06:21:30 PM »
The 45 watt Harbor Freight panels are not going to run much, but they are a start.
There is a huge difference between a trickle of electricity, and none.
Just tossing numbers, ignoring efficiency losses...

Assume your sunlight thru the year is going to range from 8 to 12 hours.  The unit generates up to 540 watt/hour per day.  To store this in a 12 volt battery it needs to be at least a 45 amp/hour battery. 

In a short term "burst", you can withdraw whatever the battery and your inverter can handle, quickly drawing down the battery. 

If I want to know the most I can withdraw 24/7, look at the short day. In 8 hours the panels must generate three times a constant daily use.  For this one unit, a 24/7 constant withdrawal limit is 15 watt.

It's the difference between some led lights and a radio, of an "indefinite" period, and not.

Inverters are not “efficient” when idling, so it may “pay” to have a variety of power sizes, and switch in the inverter appropriate for the load of the moment.

Retired, but still working in the garden...

Offline Herbalpagan

  • Survivalist Mentor
  • *****
  • Posts: 784
  • Karma: 33
Re: Harbor Freight 45 Watt Solar Panel Kit
« Reply #2 on: June 13, 2010, 07:47:06 PM »
We have two sets of these. We have yet to get the batteries and inverter though.  Several of our prepper group have them and we checked them out before buying.
on them, we can run:
HAM radio
water pump for short periods of time
small appliances, like the grain grinder etc
tv for a short while
computer
a couple of lights for an evening
recharge batteries for tools & equipment

A worth while investment for us in my opinion.
I'm always working to get ready.
shtfradio.com Thurs. 8 eastern
http://greensurviving.blogspot.com/

Offline monkeyboyf

  • Survivalist Mentor
  • *****
  • Posts: 674
  • Karma: 39
Re: Harbor Freight 45 Watt Solar Panel Kit
« Reply #3 on: June 13, 2010, 10:43:34 PM »
Herbalpagan, is your water pump 220?
We will always be prepared, so we may always be free.
 Ronald Reagan
uh, I am a female

Offline Andy in NH

  • Senior Survivalist
  • ****
  • Posts: 217
  • Karma: 13
  • Ex injuria jus non oritur
Re: Harbor Freight 45 Watt Solar Panel Kit
« Reply #4 on: June 20, 2010, 01:06:18 PM »
Pathman ,
I just picked up that kit also.  I was about to start a thread and ask some questions myself - thanks!  (I hope you don't mind me jumping on)  :-[

I've been experimenting with what this kit can do for me.

It ran my Dillon case cleaner (1.6 amps) for three hours before the inverter's low voltage cut-off kicked in.  That was plenty of time to clean load of 5.56mm brass.

I've also run a laptop and my dremel tool on it for short periods.  Recently, I picked up a 1000 watt inverter (still need to wire it up) to run some small power tools.



For those of you who have more experience with solar than I do (I'm a noob), please comment on the following:

*My assumptions:

- If I add another battery in parallel, I can increase the run time?
 
- If I add more panels, the batteries will charge faster?

Questions:

I'm having difficulty finding any information about how many of these solar panels I can connect to this single charge controller.  Is there a rule of thumb for this?

When connecting batteries, is it best to use large wires?  For example, would it be harmful to salvage an old set of jumper cables and cut them to fit between batteries?

How does this effect the wire size between the batteries and the charge controller?

How does this effect the size of the wires between the batteries and the inverter?

In my picture above, the panels are oriented directly south. Mid afternoon, they become covered by shade from trees (which are not on my property).  Would it be beneficial to adjust the angle more toward the east in order to take advantage of more sun during the morning / early afternoon?

Thanks, Andy
« Last Edit: June 20, 2010, 01:09:31 PM by Andy in NH »
Is the boy you were proud of the man you are?

Fimbo iliyo mkononi, ndio iuwayo nyoka!

Offline daved

  • Senior Survivalist
  • ****
  • Posts: 244
  • Karma: 7
Re: Harbor Freight 45 Watt Solar Panel Kit
« Reply #5 on: June 20, 2010, 09:13:13 PM »
I'm far from an expert on such things so take this for what it's worth.
I was thinking about getting those same panels and did some online research. The one thing that seemed to keep coming up is that the output tends to drop significantly after they have been in use a while. I have nothing to compare that to, so I don't know if it is common to all solar panels or not, but it didn't seem to be from what I was reading.

Offline Truik

  • Perpetual Student
  • Moderator On Leave
  • Survival Demonstrator
  • *
  • Posts: 2908
  • Karma: 65
Re: Harbor Freight 45 Watt Solar Panel Kit
« Reply #6 on: June 20, 2010, 09:24:39 PM »
I'm far from an expert on such things so take this for what it's worth.
I was thinking about getting those same panels and did some online research. The one thing that seemed to keep coming up is that the output tends to drop significantly after they have been in use a while. I have nothing to compare that to, so I don't know if it is common to all solar panels or not, but it didn't seem to be from what I was reading.

All solar panels tend to drop in voltage output gradually over time, but it could be a couple decades before you see any significant drop.

If these particular solar panels have such issues (how long is "a while") then I would be inclined to get a couple of the 30 watt panels on E-bay and tie them together. I saw a 30 watt panel go for about $60 on E-bay last week (a seller I had purchased from previously) and its just like the one I have had on my shed in the back for years.

Just my two cents.

Sign up for Dallas/Fort Worth area Meet'n'Greet e-mails: http://eepurl.com/gW6v



>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Sign up for TSP Forum Newsletter with updates and interesting forum threads: http://eepurl.com/iipvo


Offline mlwilki

  • Prepper
  • **
  • Posts: 25
  • Karma: 0
Re: Harbor Freight 45 Watt Solar Panel Kit
« Reply #7 on: June 20, 2010, 09:38:30 PM »
i  have this set and find it usefull. i currently have it running a fan and light in the chicken coop. it is a good starter kit and if you don't expect to much from it you will be very happy.

i have used 1 panel more than the others and it is lighter in coloar than the others but works just fine.

Offline Ken325

  • Survivalist Mentor
  • *****
  • Posts: 531
  • Karma: 42
  • "Winter is Coming"
Re: Harbor Freight 45 Watt Solar Panel Kit
« Reply #8 on: June 20, 2010, 10:17:19 PM »
I haven't bought yet but I am shopping.

I looked at the harbor freight set and it looks like the best value for the money.  The thing is you can by a single panel of mono-crystalline silicon solar cells and it will produce 2X the power of this 3 panel set.  The mono-crystalline silicon panel cost about $400 for a full panel but it is a lot more efficient.  I am looking at buying one of the portable mono-crystalline kits because I have very limited space.  Look at this

http://www.amazon.com/Mono-crystalline-Portable-Briefcase-Solar-Charger/dp/B000GDC2MA



It is only 30w compared to 45w but it is portable and takes up less space.

Offline PBRstreetgang

  • Survivor
  • ***
  • Posts: 122
  • Karma: 6
Re: Harbor Freight 45 Watt Solar Panel Kit
« Reply #9 on: August 14, 2010, 06:54:37 PM »
Figured I'd bump this - the kit is is on sale for $170.  Looks like it has decent reviews here so we're going to pick one up.

Harbor Freight 45 watt Solar Panel Kit

Offline fred.greek

  • Survivalist Mentor
  • *****
  • Posts: 631
  • Karma: 29
Re: Harbor Freight 45 Watt Solar Panel Kit
« Reply #10 on: August 14, 2010, 07:20:59 PM »
Hit the libraries, and check the newspapers...

Or check friends that archive papers, or recycle...

Two weeks back, our Yuma paper had a harbor freight flier with a coupon for the panels at $139.

Retired, but still working in the garden...

Offline monkeyboyf

  • Survivalist Mentor
  • *****
  • Posts: 674
  • Karma: 39
Re: Harbor Freight 45 Watt Solar Panel Kit
« Reply #11 on: August 14, 2010, 07:58:10 PM »
The flyer in the Fort Worth  paper last Sunday has the 3 panel kit for $149.99. Don't know how long it's good on that price. I need to get down there for one.
We will always be prepared, so we may always be free.
 Ronald Reagan
uh, I am a female

Offline chrisdfw

  • Dedicated Contributor
  • ******
  • Posts: 1183
  • Karma: 43
Re: Harbor Freight 45 Watt Solar Panel Kit
« Reply #12 on: August 23, 2010, 01:16:55 AM »
crystaline panels are more efficient in full sun, but thin film does better in partial shade so it is a trade off. Thin film also tends to degrade a little at first, so
your output might drop the first few months of use and then stabilize. Some panels drop from the rated output to a lower output, while some drop from a higher
value to their rated output, there is no standard.

Crystaline panels are more space efficent for the same output. They just take up less space on your roof, etc, so that can also be a concern.

Offline Bobo

  • Survivor
  • ***
  • Posts: 103
  • Karma: 4
Re: Harbor Freight 45 Watt Solar Panel Kit
« Reply #13 on: August 23, 2010, 03:45:21 PM »
Pathman ,
I just picked up that kit also.  I was about to start a thread and ask some questions myself - thanks!  (I hope you don't mind me jumping on)  :-[

I've been experimenting with what this kit can do for me.

It ran my Dillon case cleaner (1.6 amps) for three hours before the inverter's low voltage cut-off kicked in.  That was plenty of time to clean load of 5.56mm brass.

I've also run a laptop and my dremel tool on it for short periods.  Recently, I picked up a 1000 watt inverter (still need to wire it up) to run some small power tools.



For those of you who have more experience with solar than I do (I'm a noob), please comment on the following:

*My assumptions:

- If I add another battery in parallel, I can increase the run time?
 
- If I add more panels, the batteries will charge faster?

Questions:

I'm having difficulty finding any information about how many of these solar panels I can connect to this single charge controller.  Is there a rule of thumb for this?

When connecting batteries, is it best to use large wires?  For example, would it be harmful to salvage an old set of jumper cables and cut them to fit between batteries?

How does this effect the wire size between the batteries and the charge controller?

How does this effect the size of the wires between the batteries and the inverter?

In my picture above, the panels are oriented directly south. Mid afternoon, they become covered by shade from trees (which are not on my property).  Would it be beneficial to adjust the angle more toward the east in order to take advantage of more sun during the morning / early afternoon?

Thanks, Andy

Questions:
I'm having difficulty finding any information about how many of these solar panels I can connect to this single charge controller.  Is there a rule of thumb for this?

The main limitation for charge controllers is current. This harbor freight system puts out a max of 3 amps... so for a 10 amp charge controller, you could safely run 3 panels of the same type (9x 15 watt panels total)

When connecting batteries, is it best to use large wires?  For example, would it be harmful to salvage an old set of jumper cables and cut them to fit between batteries?

Given that you have a 1000W inverter (probably sized for 2000W starting surge) I would use a gauge of wiring capable of handling 170A of current.
I think jumper cables would be an excellent gauge of cables to use to connect the batteries together in parallel with your 1000W inverter. Jumper cables are designed to handle this level of current.

As a side note, I would suggest using a fuse between your battery pack and your inverter. Also use a fuse between the charge controller and the battery pack. As you add more batteries to your battery pack, the amount of energy stored can get dangerous if you short together the output.

How does this effect the wire size between the batteries and the charge controller?

it all depends on how much current is coming from the charge controller.

for a 20 amp charge controller, I would use 12 gauge wiring. If your using something smaller than a 20 amp controller, I would still use 12 gauge wiring because it's relatively inexpensive.

How does this effect the size of the wires between the batteries and the inverter?

wire sizing should be based on the max current draw from the inverter (estimated to be 170A) and the length of wire between the inverter and the battery. I would minimize the length to as short as possible. If you have a certain distance between them of significant length (more than a few feet). You will have to increase the gauge to account for the potential voltage drop. I can give more details on this if applicable

In my picture above, the panels are oriented directly south. Mid afternoon, they become covered by shade from trees (which are not on my property).  Would it be beneficial to adjust the angle more toward the east in order to take advantage of more sun during the morning / early afternoon?

It would be most beneficial to have the panels face the sun through the duration of the day. If you do move the panels to the east in the morning and move them again to the west in the evening... you will send more energy to the batteries.

Hope this helps you out!

Let me know if you have any further questions.
Pray as if everything depends on God; Act as if everything depends on you

Offline Andy in NH

  • Senior Survivalist
  • ****
  • Posts: 217
  • Karma: 13
  • Ex injuria jus non oritur
Re: Harbor Freight 45 Watt Solar Panel Kit
« Reply #14 on: August 23, 2010, 06:13:12 PM »
Hope this helps you out!

Let me know if you have any further questions.

It sure did!  Thanks!

I'm sure I'll have more questions in the future.
Is the boy you were proud of the man you are?

Fimbo iliyo mkononi, ndio iuwayo nyoka!

Offline Herbalpagan

  • Survivalist Mentor
  • *****
  • Posts: 784
  • Karma: 33
Re: Harbor Freight 45 Watt Solar Panel Kit
« Reply #15 on: August 23, 2010, 07:26:30 PM »
Herbalpagan, is your water pump 220?
no. husband is an electrician and checks these things out pretty well. (thanks though)
we also had friends over with their units and checked them out to see how they ran.
I'm always working to get ready.
shtfradio.com Thurs. 8 eastern
http://greensurviving.blogspot.com/

Offline cmxterra

  • Dedicated Contributor
  • ******
  • Posts: 1516
  • Karma: 76
  • Bugging out in style.
Re: Harbor Freight 45 Watt Solar Panel Kit
« Reply #16 on: August 24, 2010, 08:41:52 PM »
My biggest complaint about these units are they are damn fragile.

I like my "normal" solar panels much more as they are considerably more robust.

If you can I would suggest bypassing these and going strait to the real deal panels if you can afford it.
concordia discors

Oderint dum metuat

Offline Andy in NH

  • Senior Survivalist
  • ****
  • Posts: 217
  • Karma: 13
  • Ex injuria jus non oritur
Re: Harbor Freight 45 Watt Solar Panel Kit
« Reply #17 on: August 24, 2010, 09:16:16 PM »
I like my "normal" solar panels much more ...

Which make / models do you suggest?
Is the boy you were proud of the man you are?

Fimbo iliyo mkononi, ndio iuwayo nyoka!

Offline cmxterra

  • Dedicated Contributor
  • ******
  • Posts: 1516
  • Karma: 76
  • Bugging out in style.
Re: Harbor Freight 45 Watt Solar Panel Kit
« Reply #18 on: August 24, 2010, 10:39:13 PM »
What fits your budget.

The Harbor Freight ones are all a single piece of glass with little to support it. If you drop it (or drop something on them) they shatter.

The traditional solar panel that we are all used to seeing are more robust and a bit less fragile and come in an aluminum frame rather that plastic. Yes they do cost more but buy once cry once.
concordia discors

Oderint dum metuat

Offline Bobo

  • Survivor
  • ***
  • Posts: 103
  • Karma: 4
Re: Harbor Freight 45 Watt Solar Panel Kit
« Reply #19 on: August 25, 2010, 02:27:16 PM »
I home build my panels out of acrylic glass, pressure treated plywood, and use 2x4's as support brackets behind the wooden panels. This also gives the panels an air gap between the roof an panel. They end up being a bit heavier than needed, but they can take much more abuse from dropping. Each panel cost me about 65-80 dollars and puts out 50W
Pray as if everything depends on God; Act as if everything depends on you

jakematic

  • Guest
Re: Harbor Freight 45 Watt Solar Panel Kit
« Reply #20 on: September 28, 2010, 09:17:28 AM »
Reading American Rifleman this morning and there is a "coupon" in it for this kit - I can't stand it anymore, am planning to get one of these this weekend.

Any additional thoughts on these? I plan to stiffen them up perhaps with plywood based on what I've read here.

Offline slingblade

  • Senior Survivalist
  • ****
  • Posts: 295
  • Karma: 9
  • I aim to kill you with it.
Re: Harbor Freight 45 Watt Solar Panel Kit
« Reply #21 on: September 29, 2010, 09:52:58 AM »
What is the price? 

Offline Mr Ant

  • Prepper
  • **
  • Posts: 37
  • Karma: 2
Re: Harbor Freight 45 Watt Solar Panel Kit
« Reply #22 on: September 29, 2010, 06:17:07 PM »
What is the price? 

149.99....The coupon is on page 109 of the American Rifleman.

Socialism: Tax dollars at work for those who don't

Offline OldManSchmidt

  • Dedicated Contributor
  • ******
  • Posts: 1296
  • Karma: 57
  • There is such a thing as too low.
Re: Harbor Freight 45 Watt Solar Panel Kit
« Reply #23 on: September 29, 2010, 11:22:15 PM »
A few words on wire sizing.  DC power suffers voltage drop more severely than AC so wire size is more important on the DC side of the system.  Twelve gauge wire is rated @ 30 amps for the purpose of de-rating factors but limited to 20 amps protection by the National Electrical Code.  Figuring it @ 20 amps is the good rule of thumb.  With that in mind, recycled heavy duty jumper cables are a good choice.  The larger wire size allows for better transfer of power with less loss.  I would recommend using one wire size larger (two if you can afford it and make it work) than the amperage you are serving.  Here are a few NEC amperage ratings according to wire size.

NEC Table 310.16, pg. 70-148, 2008 NEC
#14=15 amp
#12=20 amp
#10=30 amp
#8=55 amp  can be protected @ 60 amp
#6=75 amp  can be protected @ 80 amp
#4=95 amp  can be protected @ 100 amp

The uprated protection amperages are per NEC Article 240.6 (A).  You are permitted to use the next higher standard rating if the wire is rated to a non standard amperage.

If using an inverter, convert to AC as close to your power house as possible and transmit your power as AC.  You don't have to oversize your wire to account for voltage drop unless you are covering truly large distances.  With wire prices these days, better to save your money for other things.
Yea, though I walk through the Valley of the Shadow of Death, I will fear no evil, for Thou art with me -- Psalm 23
If we lose freedom here, there is no place to escape to.  This is the last stand on Earth. -- Ronald Reagan
I never signed onto this gig to save the world, just my little piece of it. -- OMS

Offline Maurk

  • Fledgling Prepper
  • *
  • Posts: 5
  • Karma: 0
    • Personal Website
Re: Harbor Freight 45 Watt Solar Panel Kit
« Reply #24 on: September 29, 2010, 11:45:35 PM »
I have used that same solar kit for about 2 years and I use others as well.... but I want to point out something nobody else seemed to say about them.
They are Amorphous... meaning they will generate on a cloudy day while the poly and mono cells generate less on cloudy, but more on sunny days. Also, Amorphous cells will de-generate faster than mono and poly cells. You should get 10 years of moderate power generating, but they will produce less power and less power as the years go. Mono cells can go 25 years, but then will start falling downhill.
I have lots of trees and decided to use all types of cells, and basically just charge a pair of golfcart batteries, which power 12v lights and other 12v gadgets, occasionally using an inverter when the power goes off. My advice to you is to put your money into your battery bank rather than solar cells, but use solar to 'top off' your batteries. I also have a motorcycle battery charger on a timer for an hour each day to make sure my battery bank is full. That way even a small solar panel collection can work for you. Even that 45 watt kit will work as long as your battery bank has enough energy for your needs.
May your actions benefit both yourself and mankind....

Offline slingblade

  • Senior Survivalist
  • ****
  • Posts: 295
  • Karma: 9
  • I aim to kill you with it.
Re: Harbor Freight 45 Watt Solar Panel Kit
« Reply #25 on: September 30, 2010, 08:18:04 AM »
With that in mind, recycled heavy duty jumper cables are a good choice. 

Also good (and inexpensive) is welding cable.  It is usually sold by the foot, has a durable shielding, and is very flexible even during cold weather.

jakematic

  • Guest
Re: Harbor Freight 45 Watt Solar Panel Kit
« Reply #26 on: September 30, 2010, 10:24:29 AM »
My advice to you is to put your money into your battery bank rather than solar cells, but use solar to 'top off' your batteries.

My thought exactly - would rather invest in good batteries right now, and I also don't have idea full sun conditions. Thanks for the info Maurk and welcome to the forum!

Offline tug78

  • Fledgling Prepper
  • *
  • Posts: 8
  • Karma: 0
Re: Harbor Freight 45 Watt Solar Panel Kit
« Reply #27 on: October 07, 2010, 11:01:34 PM »
i got this kit last weekend when the harbor freight by my house had a side walk sale. $149 sale price plus a 20% off coupon that came in the mail brought the total to $119.so Ive been playing with it for a week now. its hooked up with one deep cycle battery and a cheap 300 watt inverter.so far things that work are hair clippers, desk fan, papper shredder and a 27 watt fluorescent bulb. i left  the 27 watt bulb and the two five watt bulbs that come with the kit on all night. after a day of sun the battery was back to full. stuff that diddent work, shopvac,  small dehydrator, and a 100 watt incandescent light bulb. so far i like the kit the price was right and a little redundant power is better than none. next i think i need a second battery and a better inverter.

Offline Greg687

  • Fledgling Prepper
  • *
  • Posts: 4
  • Karma: 0
Re: Harbor Freight 45 Watt Solar Panel Kit
« Reply #28 on: October 10, 2010, 09:50:42 AM »
I home build my panels out of acrylic glass, pressure treated plywood, and use 2x4's as support brackets behind the wooden panels. This also gives the panels an air gap between the roof an panel. They end up being a bit heavier than needed, but they can take much more abuse from dropping. Each panel cost me about 65-80 dollars and puts out 50W

Interesting idea Bobo.  Please link to instructions.  I've been wanting to do that for a while now.

Greg

Offline Bobo

  • Survivor
  • ***
  • Posts: 103
  • Karma: 4
Re: Harbor Freight 45 Watt Solar Panel Kit
« Reply #29 on: October 11, 2010, 03:17:37 PM »
Greg,

I've found many references online to pull ideas from. This one is one of the sources. Keep in mind you will likely not be allowed (though technically doable) to grid tie these to the house because anything you build will not be "UL rated".. blah, blah, blah... but for charging batteries, it's a perfect idea!

Below... this is 1 of 3 that I have constructed, installed on the back of my garage, maintaining a full charge on 2 marine batteries, and still working today (the first one is about 5 months old).

Pray as if everything depends on God; Act as if everything depends on you