Hi, Ron~ The Midnite Classic PV controller shows 72 volt nominal as one of the battery choices on its menu screen. That's about the only option I know of. Even though the HV controller from Apollo can accept a similar range of PV input voltage I think that unit stops at a 48v battery--maybe because of code problems with battery strings above 50 volts.
For charging a 72 volt lead battery, consider a minimum of 36 X 6 = 216 PV cells in each charging string. Confirm that "cell count" suggestion with someone who knows more than I do about the Midnite controllers...such as boB Gudgel who is a frequent List contributor. I just unboxed my first Classic controller and I look forward to learning more about this item. With a 72 volt lead acid battery bank it will be difficult to maintain equal state of charge on the 36 chemical cells in each battery string. As you know, Ron, one can only add/remove energy through the whole battery string--barring new developments--so if some of those critters get out of line it will be tough to re-establish good discipline. Jolliness, Mick Abraham, Proprietor www.abrahamsolar.com Voice: 970-731-4675 On Tue, Feb 8, 2011 at 8:07 PM, Ron Young <solarea...@solareagle.com> wrote: > Hi All, > > I recently acquired some UPS units that are a high end portable units (GE > GT3000). They are nearly new and I would like to rig them up as a standalone > emergency back-up power source with a solar (or wind) charging option. These > units have sine wave output and are a double conversion type, i.e. power out > is isolated from power in by ac to dc to ac conversion. The main problem I > have is that the battery pack is 72v. It is expandable and I can add up to > four additional packs to increase the runtime to over three hours at half > power (1200 watts). How do I charge this type of battery pack with solar? Is > there a charge controller out there that will provide nominal 72v? > http://www.gedigitalenergy.com/PowerQuality/catalog/gtseries.htm > > Best Regards, > *Ron Young* > earthRight Products - Solareagle.com > Alternative Energy Solutions ~ Renewable Energy Products > 1-877-925-2929 > *blog*: http://www.earthrightsolar.tumblr.com > *website*: http://www.solareagle.com > *email*: sa...@solareagle.com > 79F North Third Ave > Williams Lake, BC > V2G 2A3 > > > _______________________________________________ > 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 > > >
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