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Rbertalotto's avatar
Rbertalotto
Explorer
Jul 01, 2013

Why wouldn't you buy this 45watt Solar System for $149???

I'm a bit of a newby "things solar"...But for $150....Isn't this a good deal even if it is 'disposable"

http://www.harborfreight.com/solar-panel-kit-45-watt-68751.html

What would it cost to duplicate this system with "good" stuff?




Description
Solar panel kits are a great way to generate plenty of clean, quiet energy, using solar energy from the sun to run TVs, lights, computers, even recharge 12 volt DC batteries. Setting up Chicago Electric solar panel kits is easy. The solar panel kit comes with three 15 watt solar panels - simply connect the solar panels to your own 12 volt DC storage battery, and then use at least a 300 watt power inverter (sold separately) to power your 120 volt AC appliances anywhere.

Three 15 watt solar panels produce clean, quiet energy
Lightweight, weatherproof construction
Amorphous silicon solar cells for maximum output in both bright and cloudy conditions
Voltage regulator has easy-to-read LED display, 12V cigarette lighter socket, 5V USB, 3-6-9V DC outlets and two 12V sockets for the included Light Kit
Includes mounting hardware, 12V Light Kit, battery terminal clamps and universal DC power adapter

Requires 12 volt storage battery and 300 watt power inverter (sold separately).
Specifications
Name Solar Panel Kit, 45 Watt
SKU 68751
Brand THUNDERBOLT MAGNUM SOLAR
Application TVs, Lights, Computers, And Recharging 12v Batteries
Number of Panels 3
Wattage (watts) 45
Product Height 36-21/50 in.
Product Length 12-21/50 in.
Product Width 3/4 in.
Accessories Included Mounting hardware, 12v light kit, battery terminal clamps and universal DC power adapter
Warranty 90 Day

30 Replies

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  • LoudDog's avatar
    LoudDog
    Explorer
    Jul 01, 2013
    Or get a generator and charge your batteries every couple days for a few hours. Or two 6v batteries, led lights, and careful management, maybe once every 4-5 days.
  • RJsfishin's avatar
    RJsfishin
    Explorer
    Jul 01, 2013
    If you need small panels for storage etc, it maybe not be robbery, but you need at least 3 more just like them to have even 90 watts,......@ $300 total.
    And for $300 you can have a 200-300 watts system in either a single or double panel.
  • Almot's avatar
    Almot
    Explorer III
    Jul 01, 2013
    My answer is "Why would you"? :)
    45W is not a charging system, it's a maintainer, for preventing slow self-discharge with loads disconnected when rig is in storage. However, for a maintainer this is overkill, 5W-10W system is enough.

    LED lights and pumps will need 7-10 AH a day or more, depending on what lights and how often to pump. The smallest laptop needs at least 4 AH per hour, depending on the task, so let's say 8 Ah for 2 hours. Plus, self-discharge, detectors, occasional radio - 20 AH total. In case you forgot about DC circuit of propane fridge - often there is such a circuit - this is another 10-15 AH a day. Total 30 AH or more.

    To collect 30 AH in a sunny weather with a tilted panel, you need 80W-100W panel. 120W with flat panel in summer - this is on a sunny day. Plus 10A controller. Total cost around $200 plus cables. For extra piece of mind, even with such a minimalistic approach, without microwave or any other 120V devices, I would increase the system power by at least 1.5, going for 180W panel, this wouldn't cost much more. Wattage higher than 180 would result in either 2 panels, or expensive MPPT controller.

    PS: in Rv solar it's customary to measure panels in watts, and energy needs in amp-hours (AH). So don't get confused.
  • SteveAE's avatar
    SteveAE
    Explorer
    Jul 01, 2013
    You might want to first decide how much energy you use every day by doing an energy audit before buying panels and then having to adjust your usage to meet the panel output. It is surprising many Amp-Hrs. are consumed by just the everyday items, some of which run in the background) in many RV's.

    For instance, my mid-size travel trailer uses roughly 30 Amp-Hrs. per day for items like the refrigerator, water pump, CO2 detector, clock radio backlight, bath fan, etc....all before I even turn on any lights (LED) or use the furnace. There are guys who are better at this than I am (whom I am sure will chime in), but to replace that 30 Amp-Hrs. on a daily basis, I would need roughly 75 watts of solar panels (assuming 5 hours/day of peak output) with everything (panels, controllers) operating at 100% efficiency and with no wire losses....all of which are impossible). So a 100 watt panel would not be inappropriate for me. I have 300 watts, flat mounted on the roof, but use the trailer mainly in the winter when sun is at a premium.

    Hope this helps,
    Steve
  • HiTech's avatar
    HiTech
    Explorer
    Jul 01, 2013
    The rule of thumb I have seen suggested is SWAG at 5 hours a day of full output. So if it is say 3 amps peak output you might see 15 amp hours a day back into your battery on sunny days.

    LEDs are easy to keep up with if not too many or too long. laptops can be power pigs - just look at the size of the power supply in watts - up to 220 watts for some (vs 45 in solar). If you crank the speed and backlight down they can be manageable. Water pump uses a lot but may not run long.

    If what you have is working for you now, this could extend your stay a bit.

    One thing I like about this set up is when you outgrow it, it can transform into 3 individual battery maintainers.

    There are a lot of options these days in systems for $150, though when you add in shipping costs the options do narrow quickly.

    Jim
  • MEXICOWANDERER's avatar
    MEXICOWANDERER
    Explorer
    Jul 01, 2013



    It helps to keep in mind at that level of power, the panel will = roughly this gizmo plugged in for four or five hours a day. Hoover Dam, it ain't
  • Rbertalotto's avatar
    Rbertalotto
    Explorer
    Jul 01, 2013
    Thanks Jim......Your cogent comment is greatly appreciated...

    I would use it when remote camping to keep the battery in the camper charged for laptop use and a few lights (LED) for a few hours every night and to run the waterpump for a shower in the morning. Everything else would be running off Propane.

    I know I need to do more research on what these devices are drawing and would 45watts put it back during a typical day.

    I have a 10,500 watt roof top unit on my house that SolarCity installed last September. So far I'm $185 ahead of the electric utility! I love opening that bill every month and seeing a credit instead of a $230 invoice!

    So I'm no stranger to solar power, but I really don't know anything about it. I see RV systems costing near $1000 and that simply doesn't make sense to me at this stage in my RVing.

    Thanks again!
  • HiTech's avatar
    HiTech
    Explorer
    Jul 01, 2013
    It's not the worst thing in the world and the cloudy solar production might even be a bit better than other 45w set ups. But no idea what solar controller they are using. They are not all created equal.

    If you could buy that locally vs. having to pay extra to ship something else it may not be bad. The flexibility in output voltages is interesting. It is big enough to charge an iPad or 2 at the output of the bigger Apple charger, if the USB is set up to output more than half an amp.

    What would you like to do with solar? Just get your feet wet, or maintain some batteries that are not near a charger?

    Jim
  • 2oldman's avatar
    2oldman
    Explorer II
    Jul 01, 2013
    Why? Because 45w is almost nothing. A 'good deal' isn't what you pay, it's what you get.

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