The most common reason to go with a higher voltage (and thus lower current for a given overall wattage) is to allow the use of smaller conductors, which are generally easier to work with, and lower cost.
There are fractional performance advantages to 48V over 24V in *some* equipment, but the advantages typically require lab-grade equipment to measure. Equipment such as charge controllers and MPPT often benefit from operating at a higher voltage due to reduced energy loss in the copper. The above aside, Nathan appears to have mis-typed when he said: > "Wire sizing might be reduced on the low > voltage side of hings. Wire sizes *increase* for a lower-voltage system at a given wattage and the same conductor losses as in a higher-voltage configuration. A 24V system will have double the current than a 48V system at the same wattage. Larger conductors are needed if the loss is to be the same in the 24V as in the 48V configuration. Dan Sr. Engineer Exeltech Dan --- On Tue, 1/17/12, Nathan Jones <[email protected]> wrote: > From: Nathan Jones <[email protected]> > Subject: Re: [RE-wrenches] 24 vs. 48 > To: [email protected] > Date: Tuesday, January 17, 2012, 12:11 PM > > > 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 _______________________________________________ List sponsored by Home Power magazine List Address: [email protected] 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
