Lee & Joan Posted February 24, 2017 Share Posted February 24, 2017 I came across a reference to Maximum Power Point Tracking charge controllers in an older motor home magazine. What these do is allow the solar panels to continue to charge the battery under low light conditions (dawn, dusk, clouds) where panel voltage falls below the set point of the battery. You can wire your panels in series rather than parallel thus getting a much higher voltage to the controller. I my case I could wire the 4 x 12 volt panels in series and get 48 volts, or in series / parallel to archive 24 volts This also lets you use smaller wire from the panels to the controller. The controller "sees" and tracks (15 times a second) the changing voltage giving (they say) about 30% more wattage into the battery in any given day. With my 60 watt (5 amp) system a controller like these would work https://genasun.com/products-store/mppt-solar-charge-controllers/mppt-for-lead-acid/ Note that these have 4 stage battery charging with desulfation and do not produce radio interference. There are a number of brands and sizes (and prices) of these " Maximum Power Point Tracking charge controllers" that you can search for on the net. Quote Link to comment Share on other sites More sharing options...
Maineah Posted February 24, 2017 Share Posted February 24, 2017 Yeah if you increase the voltage you can use smaller wiring it is a bigger concern in large arrays and long wiring runs. Because they use PWM I'm a little skeptical about the RF noise claims for the controllers. Quote Link to comment Share on other sites More sharing options...
Lee & Joan Posted February 24, 2017 Author Share Posted February 24, 2017 Maineah, I am still looking into this. It looks like the one I was going to get limits you to 27 volts input. I have noticed my panels put 20 some volts out if not hooked into anything so I am concerned if the Genusuns would take a series hookup. The genusuns seem to have the claim of no noise while others don't and have dry capacitors where others use cans, and a better 4 stage charger, and cheaper... your thoughts? Quote Link to comment Share on other sites More sharing options...
Maineah Posted February 24, 2017 Share Posted February 24, 2017 Yes if a 12 volt panel is in full bright noon sun it can do as much as 22 volts but the controller has no problem with that it is part of the design and expects to see that much voltage. The same of course holds true for 24 volt controllers. They are PWM (pause width modulation) devices what they do is regulate by time, the higher the voltage the less time they are on so it reduces the the overall voltage to some thing the battery can deal with. As the battery voltage drops the regulators allow a greater on time that's a simple explanation there is a little more to it but that's the basic ideal it does this pretty quickly and that is why they can be RF noisy because they turn on and off. Mine will produce a faint but obvious motor boat sound in the radio. Quote Link to comment Share on other sites More sharing options...
deannak Posted February 27, 2017 Share Posted February 27, 2017 I just installed an MPPT controller yesterday, along with 200W of semi-flexible solar panels. This morning, it was taking 40V from the panels and converting it to the recommended 14.5 to deliver to the battery. I've got high hopes, but will have to watch it over time to see how it really performs. Quote Link to comment Share on other sites More sharing options...
Lee & Joan Posted March 2, 2017 Author Share Posted March 2, 2017 Hi Deannak, which controller did you get? Are you hearing any radio interference? Quote Link to comment Share on other sites More sharing options...
rigger camper Posted April 18, 2017 Share Posted April 18, 2017 (edited) I just installed a 200w mppt kit from renogy. It works very well. The controller was a little bigger and more expensive than the pwm model but my buddy who installs solar recommended it as a better product. https://www.renogy.com/renogy-200-watt-12-volt-solar-starter-kit-w-mppt-charge-controller/ Edited April 18, 2017 by rigger camper Quote Link to comment Share on other sites More sharing options...
WME Posted April 18, 2017 Share Posted April 18, 2017 Good info from buddy. Quote Link to comment Share on other sites More sharing options...
Lee & Joan Posted June 8, 2017 Author Share Posted June 8, 2017 Some good info here on RV solar systems https://handybobsolar.wordpress.com/the-history-or-how-did-i-end-up-so-angry/ https://handybobsolar.wordpress.com/2015-midnite-classic-problems/ Quote Link to comment Share on other sites More sharing options...
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