Author Topic: Harbor freight 45 watt panels  (Read 2119 times)

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Otto

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Harbor freight 45 watt panels
« on: February 14, 2017, 01:14:38 PM »
Hello, it has been years since I have visited the Other Power. I have some old Harbor freight 45 watt panels on my roof and I haven't checked for a very long time if they are charging my 12 volt batteries. Recently I checked and there is no power to the batteries so I checked the wires from the panels going into the regulator and found that there is no DC voltage going in but there is around 48 AC volts. First off, I always thought they were producing DC voltage, secondly, if they are to produce AC, is there a bridge rectifier within the harbor freight regulator that converts it to DC?  Lastly, I had some old bridge rectifiers laying around from my old wind turbine system. I tried connecting the AC power from the solar panels to the rectifier but it dd not get converted to DC. I am not the best when it comes to understanding this stuff, so am I doing something wrong here?
Any advice is appreciated, Thank you

OperaHouse

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Re: Harbor freight 45 watt panels
« Reply #1 on: February 14, 2017, 01:44:58 PM »
You are picking up random noise from power lines or radio waves.  Most likely your panels are dead, the fate of many of these.  They have poor connections easily destroyed by moisture.

Bruce S

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Re: Harbor freight 45 watt panels
« Reply #2 on: February 14, 2017, 01:50:28 PM »
The HF solar panels certainly are DC only. When measuring in AC what was the AC setting? My freebie meter show either 200Vac or higher, even tho it will read down in 12Vac easily enough.

IF they are fairly easy to reach, I would remove the screws holding the cable backs on and measure there. I had one were the lead in cable went bad just outside the box.

Hope this helps
Bruce

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DamonHD

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Re: Harbor freight 45 watt panels
« Reply #3 on: February 14, 2017, 02:07:35 PM »
In what I take to be the UK equivalent of HF panels, 'TopRay Solar' from Maplin, I've had a little less than 50% failure rate after (say) 2 years' use I estimate, with panels going open circuit and no longer pushing out any energy.

Rgds

Damon

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Re: Harbor freight 45 watt panels
« Reply #4 on: February 15, 2017, 02:35:10 AM »
You are picking up random noise from power lines or radio waves.  Most likely your panels are dead, the fate of many of these.  They have poor connections easily destroyed by moisture.

Before giving up totally on the panels, disconnect them from the regulator and test their open-circuit voltage again.  The regulator could be faulty and pulling them down.  If you get nothing from your panels, disconnect them from each other and test them individually.

Note that some multitesters don't have a DC blocking capacitor for their AC scales.  Instead they have a half-wave rectifier and scale the reading to give you the RMS equivalent if it's hooked to an AC source with no DC offset.  Hook a battery or other DC source to them and, in one direction, you'll get a reading somewhat higher than the DC voltage of the battery.  Combine that with a failed DC scale and you could get the effect you're seeing.  It's a long shot, but not impossible.

Check your meter by trying both the DC and (in both directions) the AC scale you're using by measuring a known good battery.

Having said all that, don't get your hopes up that any of the panels are still any good.

Mary B

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Re: Harbor freight 45 watt panels
« Reply #5 on: February 15, 2017, 05:37:12 PM »
Solar Boulevard ( www.solarblvd.com ) has better quality 12 volt panels for around 80 cents a watt now. Far cheaper than the harbor fright toys!

DamonHD

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Re: Harbor freight 45 watt panels
« Reply #6 on: February 16, 2017, 02:51:16 AM »
Indeed, I can now buy nice mono panels for less per watt than that!

http://www.earth.org.uk/expanding-off-grid-PV-system.html

Rgds

Damon

george65

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Re: Harbor freight 45 watt panels
« Reply #7 on: February 20, 2017, 10:16:58 PM »

New panels here are at or below .64C/watt and are a decent brand.

You can get the top name brands for under .80 C /watt.

The brand name used panels I just picked up which are working better than I expected, cost me 4.75 Cents per watt.
Got to be happy with that!

At the rate they have been generating the last 2 days which has been cloudy and even though they get Shadowed, they will repay themselves in 5 months. Allowing for a winter dropoff ( which may not happen here) I'll still be well in front in 12 months thats for sure!

Otto

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Re: Harbor freight 45 watt panels
« Reply #8 on: February 27, 2017, 08:31:19 AM »
Well I feel very foolish. My problem was entirely operator error. When measuring the DC voltage going into the regulator I had the meter set at 20 DC volts and there is actually 23 DC volts coming in. Once I set the meter to 200 DC volts everything registered correctly. In addition my regulator is also working correctly it just wasn't in the on position. Thank you for your help.

Bruce S

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Re: Harbor freight 45 watt panels
« Reply #9 on: February 27, 2017, 08:46:59 AM »
That's good to see. Glad it worked out.
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