Hi Mark I think it's other things that help to determine it Array size and therefore # of CC Battery size and # of parallel banks Inverters and cabling
This system at 24v requires 2 CC, 4 parallel strings and dual 4/0 cables vs a 48v would be single CC, 2 strings batteries and a single 4/0. In the it's just cheaper in this case and better in terms of battery design My thoughts Jay Sent from my iPhone On Jan 17, 2012, at 11:19 AM, "Mark Frye" <ma...@berkeleysolar.com> wrote: > Interesting. > > I can choose an OB VFX3524 w/ 85 ADC or an OB VFX3648 w/ 45 ADC of charging > capacity. > > And assuming that I need C/10 during bulk charging (and the importance of > this is really what I am asking about) then: > > VFX3524: 85 ADC * 10 = 850 AH * 24 VDC = 20.4 kWH battery bank > > VFX3648: 45 ADC * 10 = 450 AH * 48 VDC = 21.6 kWH battery bank > > OK, so it's about a wash either way in terms of stored energy. > > But assuming for the moment that distances are short and the initial > difference in copper costs are small, wouldn't you rather have half the > number of individual cells to maintain...less watering, less SG measuring, > lower overall "part" (individual 2V cells) count? > > Mark Frye > Berkeley Solar Electric Systems > 303 Redbud Way > Nevada City, CA 95959 > (530) 401-8024 > www.berkeleysolar.com > > -----Original Message----- > From: re-wrenches-boun...@lists.re-wrenches.org > [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of R Ray > Walters > Sent: Tuesday, January 17, 2012 10:38 AM > To: RE-wrenches > Subject: Re: [RE-wrenches] 24 vs. 48 > > The only advantages of 24 v are that you can create smaller KWH battery > banks, and that Bergey's XL.1 was only available in 24 v. > Anytime the design allows, I jump to 48 v. > > R. Walters > r...@solarray.com > Solar Engineer > > > > > On Jan 17, 2012, at 11:11 AM, Nathan Jones wrote: > >> >> >> Mark, >> It would seem to be a wash. As the voltage is halved the amperage is > doubled in the battery bank. This would seem to require doubling the > charging amperage so nothing is gained. On a system of any size the 48 volt > gets the default nod here. Charge controllers handle twice the solar. > Parallel battery strings are eliminated, or at least held to two. Wire > sizing might be reduced on the low voltage side of things. And much easier > future expansion possibilities, too. >> Cheers, >> Nathan Jones >> Power Source Solar Inc >> >> >> ------------------------------ >> On Tue, Jan 17, 2012 10:56 AM CST Mark Frye wrote: >> >>> Not really on topic to Jay's question, but... >>> >>> Is 48v always better than 24v? >>> >>> How important is bulk charging current to overall battery life? >>> >>> In some cases, isn't it better to use a 24v inverter/charger which >>> can develop a higher charge current for a battery bank that has a >>> higher AH rating? >>> >>> Mark Frye >>> Berkeley Solar Electric Systems >>> 303 Redbud Way >>> Nevada City, CA 95959 >>> (530) 401-8024 >>> www.berkeleysolar.com >>> >>> -----Original Message----- >>> From: re-wrenches-boun...@lists.re-wrenches.org >>> [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of jay >>> peltz >>> Sent: Tuesday, January 17, 2012 8:43 AM >>> To: RE-wrenches >>> Subject: [RE-wrenches] battery buss bars >>> >>> Hi All, >>> >>> Where do I find buss bars for a battery parallel problem? >>> >>> I've got to fix a brand new ( not me) system, that has 4 sets of >>> L-16's at 24v. >>> Yea yea why didn't they go to 48? >>> >>> So I want to use buss bars to parallel them, and looking for premade > ones. >>> >>> Thanks in advance, >>> >>> Jay >>> >>> Peltz power >>> >>> _______________________________________________ >>> 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 >> >> > > _______________________________________________ > 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 > _______________________________________________ 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