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Post Info TOPIC: 120 W folding Solar Panel Overcharging
reyasmit


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120 W folding Solar Panel Overcharging
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I have installed my original 120 w panels on the roof of the van, they work well through a Solarex S8 charge controller. I have a second set of 120 w freestanding panels working through a PWM charge controller which is supposed to cut out when battery voltage reaches approx 14.5 v, this does not happen - battery voltage goes to 16+ v within 10 minutes and amp meter shows still charging at 6 amps - this gradually reduces to about 3 amps after 1/2 hour.

I have just received and installed a new regulator ( said to be MPPT type but I have strong doubts about that), It does exactly the same thing - does not switch over to top-up charging once it reaches 14.5 v.

Has anyone suffered from this problem and do you have a solution?

Thanking you all in anticipation - Tim 



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justcruisin01


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Are you connecting the portables to the same battery as the roof mounted units, if so there maybe some voltage confusion between the two regulators. Try disconnecting the roof system & then connect  the portables & see what the result is.

JC.



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reyasmit


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Thanks J.C. I'll try that as soon as the sun comes up tomorrow. I was thinking of disconnecting the roof top ones from their regulator and puting the free standing ones through it. I'll try both tomorrow Thanks again 



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oldtrack123


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HI tim

Some info on the regulator may help ,did you follow the set up procedures ?

.does it have adjustable settings for battery type"Strange that you have two different regs giving the same problem

Some times having TWO MPPT regs operating into the same battery can give problems ,but the problems are less likely with TWO PWM reg;

Suggest you cover one set of panels & see if that reg works OK, then uncver & repeat covering the other panel

That should indicate that each reg is working ok on it's ownsmile

 

PeterQ



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reyasmit


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Thanks Peter - the van is under cover when not being used so roof solar is not working. I have installed a second battery in the rear of the Pajero - I will disconnect it from the vehicle wiring and use it to test if the newly fitted reg is working properly on it. Would you believe I have another PWM upgrade coming this week to test also? Both it and the so called MPPT were about $11 each from Honk Kong so I'm not that much out of pocket - I thought it was worth a go. There is heaps of info on net and a very good report from a Yank on a genuine MPPT from Taiwan for A$139. I'll probably end up buying that.
Thanks for your advice - May is our next planned trip so plenty of time to sort thinks out. - Tim

P.S. I multi-meter tested the panels themselves and they are spot on specs.

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reyasmit


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Thought I had the problem solved - all went to specs on the isolated battery in rear of car initially. Moved the panels to caravan - straight up to 16v charging @ 6 amps - disconnected roof solar reg - no change. Put the panels back on the car rear battery after draining down to 12.2 v charged to 14.38 and sat there for at least 10 minutes while talking to the neighbour and suddenly went to 17.2 v !!! My brother is a retired electrical engineer who lives in the U.S. I've left him to ponder on the problem as well while I get over my headache.
Thanks for all the thoughts - Tim

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PeterD


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Sounds like you have found out the value of cheap regulators. Try a better regulator.

As an alternative you could wire the external panels in place of your roof mounted panels whilst the van is at home. You know the regulator in your van is OK.

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Nissan Navara D23 diesel auto, Spaceland pop-top
Retired radio and electronics technician.
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dorian


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If you're into building kits, Silicon Chip magazine published an MPPT design in 2011 and 2012. Altronics are selling it for $60.

www.siliconchip.com.au/Issue/2011/February/Build+A+12-24V+3-Stage+Solar+Charge+Controller
www.siliconchip.com.au/Issue/2012/March/12-24V+MPPT+Solar+Charge+Controller+Rev.1
www.altronics.com.au/index.asp

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reyasmit


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Thanks again folks - I think you are right Peter - shell out and buy a quality regulator will probably be the solution, I have the van reg disconnected at the moment and will be trying the panels direct through that a.s.a.p. - Tim

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dorian


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reyasmit wrote:

Would you believe I have another PWM upgrade coming this week to test also? Both it and the so called MPPT were about $11 each from Honk Kong so I'm not that much out of pocket - I thought it was worth a go. 

 If the cheap "MPPT" is of no use to you, could you indulge us by uploading a close-up photo of the innards? 



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reyasmit


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Didn't get your name but I had removed the back plate when I first got it, without taking printed circ. out all that is visible is what looks like 3 Triacs - there are no wire wound ferite cores visible. However I think I have found my problem.
As the rooftop reg. works well I decided there may be some voltage drop confusion for the reg attached to the panels rather than being near the battery. So I installed the reg on 6" leads direct to the battery and now have the long lead between the panels and the reg. - Both regulators work perfectly so far on the test battery. Yet to install in the caravan.

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dorian


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Triacs are used for AC applications. Must be something else ...


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reyasmit


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Yes - I.m only a trial & error electrician - its just what they look like.

However my problem appears solved I did as per previous post and either regulator works perfectly installed in the caravan - my thanks to all who contributed.

Should I do something to close this subject or does it close after a certain period? - Tim

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