One problem you are facing is the apparent state of charge is reflected by battery terminal voltage is a very inacurate measure. It is of course affected by rate of charge and discharge.
Another approach would be to use the FN-DC and set it to alarm on state of charge instead of voltage. (The FN-DC can be set to track SOC) This is far more accurate than battery terminal voltage control. The problem that will be raised is the ultimate state of charge drifts over time if the battery efficiency is not set correctly. If the charging is "trued up" during equalize even this problem is solved. Darryl --- On Tue, 2/24/09, robert ellison <reelli...@gmail.com> wrote: > From: robert ellison <reelli...@gmail.com> > Subject: Re: [RE-wrenches] Stand-Alone DC Relays? > To: "RE-wrenches" <re-wrenches@lists.re-wrenches.org> > Date: Tuesday, February 24, 2009, 5:53 AM > the link 10 would do it also. but not the > 'cheap" one > > bob > > On Mon, Feb 23, 2009 at 4:38 PM, jay peltz > <j...@asis.com> wrote: > > > Hi Walt, > > Have you tried the solar converters VCS units. > > They come active high and low, each unit will do from > 12-48v systems. > > Up to 30 amps dry contact relay > > totally adjustable voltage hi/low > > > > jay > > > > peltz power > > > > On Feb 23, 2009, at 1:33 PM, Walt Ratterman wrote: > > > > Hello, > > > > In our off-grid systems in Africa, we have been using > the AUX relay on the > > FX to perform an alarm function (instead of starting a > generator that might > > not start.) We use the GenAlert programming to > energize and de-energize an > > alarm on two voltage settings. (low battery, and > recovered battery….) > > > > We have some instances where we are trying to retrofit > a similar alarm > > situation into an inverter system that has no > programmable relays. > > > > Any ideas as to what equipment we could use to take > the place of the AUX > > contact on the FX? WE can deal with either wet or dry > contacts, but the > > tricky part is being able to set the voltage on and > off points. We are > > dealing with both 48V and 24VDC systems. > > > > Thanks, > > > > Walt > > > > *Walt Ratterman* > > *SunEnergy Power International*** > > * * > > 11 Laurel Lane South Washougal, WA 98671 > > (360)-837-3680 ▪ fax (360)-837-1315 ▪ > Skype Walt-Mobile > > wratter...@sunepi.org ▪ www.SunEPI.org > <http://www.sunepi.org/> > > > > > > _______________________________________________ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
