Just another thought- If redundancy is an issue with string sizing, having a 12v inverter handy is sometimes a viable backup option with a 24v bank with 2 or more parallel strings.
Jason Szumlanski Fafco Solar On May 31, 2011, at 7:55 PM, "Jason Szumlanski" <ja...@fafcosolar.com> wrote: > If the choice is one or three, I choose one. If the choice is one or two, I > choose two for the same redundancy benefit echoed by others. However, it > sometimes depends how remote the system is. > > If you are a few miles down the road from a stocking battery distributor, one > string is great. If you are a boat ride or a 10 hour 4x4 crawl at 2 mph away, > redundancy may be critical. It all depends on the situation. I would even > consider three strings if the location has serious access problems and the > customer can only "survive" with 33% capacity loss for a period of time. > > While I have my favorite brands, sometimes you have to go with a brand that > fits the right capacity and string arrangement. Fortunately Rolls has lots of > options, so you should find a suitable alternative. I start with my desired > V, aH, and parallel strings, then let the manufacturer or distributor do the > work and recommend options. Not that I don't do my research, but sometimes > they come up with a better option than you initially think of. > > Jason Szumlanski > Fafco Solar > > On May 31, 2011, at 6:25 PM, "Brian Mehalic" <br...@solarenergy.org> wrote: > >> Hi Wayne- >> While I think a lot of folks will agree that a single string is better for >> the long term health of the batteries as it results in more even charging, I >> still like the idea of at least two strings. That way if a single battery >> fails, that string can be removed and the end-user can at least get by on >> half of the pack until a replacement can be installed. >> Brian >> >> On Tue, May 31, 2011 at 10:19 PM, James Surrette <ja...@surrette.com> wrote: >> Hi Wayne, >> >> I look forward to the input from the wrenches. >> >> My recommendation, regardless of the brand, would be for one string. >> >> Regards, >> >> Jamie >> >> >>> Wayne Irwin <wa...@pureenergysolar.com> 5/31/2011 6:49 PM >>> >> Hello Esteemed Battery Gurus, >> >> Which of the following do you believe is the better 24 V battery bank? >> >> A) 13 - Rolls 2-YS-31 2430 AH @ 20 HR (one string) >> >> or >> >> B) 9 - Rolls 8-CS-25P 820 AH @ 20 HR (3 strings of 3) >> >> Thank you in advance for your input! >> >> >> Wayne Irwin, EE >> Director of Engineering >> Pure Energy Solar International Inc. >> State Licensed Solar Contractor >> License # CVC56695 >> wa...@pureenergysolar.com >> http://pureenergysolar.com >> 352 377-6527 Office >> 352 336-3299 Fax >> 352 316-1637 Cell >> The content of this message is Pure Energy Solar Confidential. If you are >> not the intended recipient and have received this message in error, any use >> or distribution is prohibited. Please notify me immediately by reply e-mail >> and delete this message from your computer system. Thank you. >> >> >> This email and its attachments have been scanned by iConnection E-Mail >> Firewall for viruses, spam, and malicious content. The information >> transmitted in this email is intended only for the entity or person to which >> it is addressed and may contain confidential/privileged material. If you >> received this in error, please contact the sender and delete the material >> from any computer. Any review, retransmission, dissemination, or other use >> of this information by persons or entities other than the intended recipient >> is strictly prohibited. %^^% >> >> _______________________________________________ >> 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 >> >> >> >> >> >> -- >> ======================== >> Brian Mehalic >> NABCEP Certified Solar PV Installer™ R031508-59 >> IREC ISPQ Certified Affiliated Instructor/PV US-0132 >> PV Curriculum Developer and Instructor >> Solar Energy International >> Carbondale, CO 81623 >> http://www.solarenergy.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 >> > _______________________________________________ > 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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