On Wed, Apr 08, 2009 at 06:13:27AM -0700, William Sellar wrote: > The thread on charge controllers caused me to wonder about controlling > multiple charging sources. If one has a solar panel with a controller, a > wind gen with a controller and say a water gen with a controller is there > a danger of these devices interfering with each other? Seems like this > could happen if the batteries where near full when the voltage was > rising. For example, if the wind gen is running, the solar controller > would see a high voltage and reduce its output. Is this an issue? If > so, how have others solved this?
Doesn't seem to be an issue in practice - both my solar panels and my wind gen have been pumping quite nicely at the same time (we've had 25kt or so winds for the past couple of days, so I was smiling every time I passed my electronics panel. Like money rolling into the bank...) It also doesn't seem to be much of an issue in theory, either, from where I see it. The thing that determines the regulation at all the controllers is the system voltage - not voltage that may have been produced by other sources in open-circuit or low-load situations. This follows from my earlier point about parallel circuits: if the battery is at, e.g., 11 volts and a solar panel that was putting out 20 volts at no load is connected to it, the system voltage is going to be right around 11 volts (the exact figure will depend on the size of the battery and the output produced by the solar panel, of course, but the ratio is usually pretty high in favor of the battery.) By the same token, until that battery is pretty nearly charged, its capacity for absorbing current is going to remain rather high - enough to sink whatever the average power setup can produce - which means that the system voltage is going to remain low enough to keep the regulators (however many of them there are) wide open. As a personal note/quirk, I wish that more of these controllers/ regulators would allow setting their nominal output voltage a bit higher as an option. I use large lead-acid (golf-cart) batteries, and they are much happier charging at 14.4 than at the slightly lower voltages set by most manufacturers (presumably driven by fear of destroying gel cells, etc.) In all my experience, heavy-duty lead acids charge much faster when driven at max, and last just as long or perhaps even a bit longer than otherwise. -- * Ben Okopnik * Editor-in-Chief, Linux Gazette * http://LinuxGazette.NET * _______________________________________________ Liveaboard mailing list [email protected] To adjust your membership settings over the web http://www.liveaboardnow.org/mailman/listinfo/liveaboard To subscribe send an email to [email protected] To unsubscribe send an email to [email protected] The archives are at http://www.liveaboardnow.org/pipermail/liveaboard/ To search the archives http://www.mail-archive.com/[email protected] The Mailman Users Guide can be found here http://www.gnu.org/software/mailman/mailman-member/index.html
