I know this isn't Facebook, but if there were a 'like' button, I would click it.
This is probably a more common question than we realize, and I agree with the answer by Allan/Bob-O. I wonder if we could convince Solar Converters, Inc. to make a cost effective and flexible DC converter to boost the PV voltage and make this possible. *Jason Szumlanski* *Fafco Solar * On Tue, Jun 4, 2013 at 1:34 PM, Allan Sindelar < al...@positiveenergysolar.com> wrote: > Eric, > Please explain further, as what you wrote makes no sense to me. Mac didn't > indicate whether he wanted to charge a flooded battery (~29.2V) or sealed > (~28.4V). The C-series of PWM controllers has a fixed two-hour absorption, > which it only counts down once the bulk voltage is reached. If the bulk > voltage setpoint is above the MPP of the module, as it is in this case, how > can it ever reach float, as you suggest? > > And further, this is spec-sheet calculation. In all but the coldest winter > weather, the Vmp of the module will be lower still as the module > temperature rises above 25ºC, and is likely to be even below the float > voltage in hot weather. And in the winter, if the battery is also cold, it > will need a higher voltage still to get fully charged. > > So I'm with Bob-O on this one. You can't charge a 24V battery with a 20V > module. Please tell us how I'm wrong. > Thanks, Allan > > P.S. - And while I'm on a virtual roll, please tell your engineering folks > to build a charge controller with a higher voltage input window. I don't > mean 600 volts at $1,500 or whatever it is; just higher than 150V. On a 48V > system, we're stuck with series strings of three modules if we use the > lowest-cost-per-watt 60-cell modules. That means that systems have to be > designed with arrays in ~750-watt increments. Give us another 50-100V or so > of headroom, so we can design with strings in multiples of 3, 4, or 5. > Outback, are you listening too? The Midnite Classic does this for us... > Thanks. > > *Allan Sindelar* > *al...@positiveenergysolar.com* <al...@positiveenergysolar.com> > NABCEP Certified Photovoltaic Installer > NABCEP Certified Technical Sales Professional > New Mexico EE98J Journeyman Electrician > Founder and Chief Technology Officer > *Positive Energy, Inc.* > 3209 Richards Lane (note new address) > Santa Fe, New Mexico 87507 > *505 424-1112* > *www.positiveenergysolar.com* <http://www.positiveenergysolar.com/>**** > > ***************** > * > > On 6/4/2013 10:43 AM, eric.bent...@schneider-electric.com wrote: > > > Hi Mac, > > A PWM charge controller, such as the C35, will work in this application, > because it will > act like a switch that connects the panel to the battery. While the bulk > voltage will likely be slightly > higher than Vmp, once the controller transitions to float, which is approx > 27V for most battery types, > it should allow the module to operate very close to Vmp. > Typically, MPPT controllers require a higher Vmp than the target charge > voltage. > > Eric Bentsen > > _____________________________________________________________________________________ > * > Eric Bentsen* | * Schneider Electric ** | Solar Business* | *UNITED > STATES* | *Technical Support Representative* * > Phone:* +(650) 351-8237 ext. 001# | * > Email:* > *eric.bent...@schneider-electric.com*<eric.bent...@schneider-electric.com> | > *Site:** > www.schneider-electric.com/solar*<http://www.schneider-electric.com/solar> | > *Address:* 250 South Vasco Rd., Livermore, CA 94551 > * > * <http://www.schneider-electric.com/solar> > *** Please consider the environment before printing this e-mail > > > > From: Mac Lewis <maclew...@gmail.com> <maclew...@gmail.com> To: RE-wrenches > <re-wrenches@lists.re-wrenches.org> <re-wrenches@lists.re-wrenches.org> > Date: 06/04/2013 08:05 AM Subject: [RE-wrenches] 24V charging with 60 > cell modules Sent by: re-wrenches-boun...@lists.re-wrenches.org > ------------------------------ > > > > Hello wrenches, > > Is there a good method to charge 24V battery bank with single 60 cell > modules? Ideally, I'd like to charge a 24 V bank with a Kyocera 245GX-LFB. > However, at NOTC the Vmp is 26.8V. Any good way to do this? > > Thanks in advance. > -- > > > > Mac Lewis > > "Yo solo sé que no sé nada." -Sócrates > > > ______________________________________________________________________ > This email has been scanned by the Symantec Email Security.cloud service. > ______________________________________________________________________ > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Change email address & 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 > > > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Change email address & > 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 > > > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Change email address & 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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