Interesting. Could you use a charge controller, like a C40 for this purpose?
Having asked that, I really try to avoid multiple systems on one property. One battery bank is trouble enough... Wm > On Jan 2, 2020, at 3:23 PM, Ray <[email protected]> wrote: > > > How do you insure proper charge voltage to the 12 v set? Never tried that > one. > > Ray Walters > Remote Solar > 303 505-8760 > On 1/2/20 1:37 PM, Chris Worcester wrote: >> I would like to add that you don’t need to get rid of the 12 v battery bank, >> but use it for the high amp draw buffer, like a large capacitor. Then use >> the DC to DC converter between the two battery banks. Done this for years on >> multiple off grid systems. >> >> Chris Worcester >> Solar Wind Works >> NABCEP PV Installation Professional >> Office 530-582-4503 >> Cell 530-448-9692 >> www.solarwindworks.com >> [email protected] >> >> From: RE-wrenches [mailto:[email protected]] On >> Behalf Of Tom Duffy >> Sent: Wednesday, January 01, 2020 8:55 AM >> To: RE-wrenches >> Subject: Re: [RE-wrenches] combining 24v and 12v systems >> >> Agree! use a Victron DC to DC Converter >> >> Kind regards >> >> Tom Duffy >> Senior Solar Design Engineer >> >> If you don’t have the Time or Money to do it right in the first place, how >> will you get the Time and Money to fix it? >> <image004.jpg> >> [email protected] >> MAIN TOLL FREE: 888-826-0939 >> DIRECT: 888-503-6772 >> International: 001-575-539-2111 >> PANAMA: 507-836-5588 X 122 >> FAX: 520-844-8442 >> www.thesolarbiz.com >> >> From: RE-wrenches <[email protected]> On Behalf Of >> Allan Sindelar >> Sent: Tuesday, December 31, 2019 6:51 PM >> To: RE-wrenches <[email protected]> >> Subject: Re: [RE-wrenches] combining 24v and 12v systems >> >> Agreed: no 12v tap. I’ll add (with modest experience, as this doesn’t come >> up as an upgrade very often any more) that Mean Well, despite the odd name, >> proved itself pretty reliable in some early Wattsun tracker drives and some >> other DC-DC applications. Available online; see >> https://www.meanwell-web.com/en-gb/dcdc-converters/ >> Allan >> >> On Dec 31, 2019, at 10:46 AM, Dan Fink <[email protected]> wrote: >> >> I second everyone. Center-tapping a 24 or 48v battery bank for 12v SEEMS >> like it should work just fine, especially for low load infrequent use like a >> 12v water pressure pump for a greenhouse, a weather station, etc.. Nope, >> I've been a loser every time, with that battery or pair always the first to >> go bad. >> >> Samlex and Victron both make DC-DC converters I have had good luck with; >> they are thermally protected and you can stack multiple units for more >> amperage. >> >> Dan Fink >> Executive Director, Buckville Energy Consulting >> NABCEP PV Associate >> NABCEP Certified PV System Inspector >> IREC Certified Instructor™ for: >> ~ PV Installation Professional >> ~ Small Wind Installer >> NABCEP Registered Continuing Education Providers >> [email protected] >> 970-672-4342 >> >> >> >> >> On Tue, Dec 31, 2019 at 10:57 AM Ray <[email protected]> wrote: >> Even with battery balancers, battery tapping is still a really bad idea. I >> know, I did it on my own system in the 90s. The DC/DC converters are the >> way to go, but be sure and over size it by a fair amount to handle the >> fridge starting surge. Unfortunately my favorites are no longer available: >> made by Solar Converters in Canada. I've seen them last decades. Iota >> should be good stuff, their chargers have long term reliability. Samlex >> inverters have been around for quite a while too, but I don't have long term >> experience with their converters. >> >> Ray Walters >> Remote Solar >> 303 505-8760 >> On 12/31/19 10:05 AM, Dave Angelini Offgrid Solar wrote: >> Tapping a battery bank is not a good practice. it will unbalance the bank. >> Much better to add a 24V electronic converter for the 12V loads. Then >> replace the 12V loads when time permits. They will need a spare converter so >> buy 2. Amazon has tons of these converters. Your quote is great BTW. H N Y ! >> >> >> Dave Angelini Offgrid Solar >> "we go where powerlines don't" >> http://members.sti.net/offgridsolar/ >> e-mail [email protected] >> text 209 813 0060 >> On Tue, 31 Dec 2019 11:52:20 -0500, Chris Schaefer >> <[email protected]> wrote: >> >> G'day and Happy New Year to All, >> >> Recently came across this offgrid OB FX system. The first part is a 12v >> battery system w/ 2 PV modules, 2 Trojan L16 batteries used to power a frig >> and freezer about 6 years old. The second is a 24v with 3kw of PV, 4 Trojan >> L16's, twin OB FX inverters installed by an HVAC contractor back in 2016. >> This was their first offgrid project. Oh boy, lol. The client would like to >> add more battery capacity to both. My thought here is since we are powering >> only a 12v frig and freezer why not simplify the system by creating a single >> battery bank and then tapping off of the 24v bank using proper fusing and >> creating a 12v buss? Admittedly I live in a 48v world so I'm asking our >> esteemed colleges as to options on how to address this. >> >> Oh yeah, the installer is unresponsive (no surprise there) and they are also >> having firmware issues with an old Mate 3 and would like me to install a new >> Mate 3s but that's another issue I'll tackle when I head out to site. >> >> Thanks All, >> Christopher- >> Chris Schaefer's >> <image006.jpg> >> >> Tel/Fax 585-229-2083 or Cell 585-748-1870 >> 5115 South Hill Road ~ Canandaigua New York 14424 >> www.solarandwindfx.com ~ E-mail: [email protected] >> >> <image008.jpg> >> >> Thomas Jefferson, the author of our great Constitution, once said, >> "democracy" will cease to exist when you take away from those who are >> willing to work and give to those who would not." >> >> -- >> >> >> >> _______________________________________________ >> List sponsored by Redwood Alliance >> >> List Address: [email protected] >> >> Change listserver email address & settings: >> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >> >> List-Archive: >> http://www.mail-archive.com/[email protected]/maillist.html >> >> List rules & etiquette: >> www.re-wrenches.org/etiquette.htm >> >> Check out or update participant bios: >> www.members.re-wrenches.org >> >> _______________________________________________ >> List sponsored by Redwood Alliance >> >> List Address: [email protected] >> >> Change listserver email address & settings: >> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >> >> List-Archive: >> http://www.mail-archive.com/[email protected]/maillist.html >> >> List rules & etiquette: >> www.re-wrenches.org/etiquette.htm >> >> Check out or update participant bios: >> www.members.re-wrenches.org >> >> _______________________________________________ >> List sponsored by Redwood Alliance >> >> List Address: [email protected] >> >> Change listserver email address & settings: >> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >> >> List-Archive: >> http://www.mail-archive.com/[email protected]/maillist.html >> >> List rules & etiquette: >> www.re-wrenches.org/etiquette.htm >> >> Check out or update participant bios: >> www.members.re-wrenches.org >> >> >> >> _______________________________________________ >> List sponsored by Redwood Alliance >> >> List Address: [email protected] >> >> Change listserver email address & settings: >> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >> >> List-Archive: >> http://www.mail-archive.com/[email protected]/maillist.html >> >> List rules & etiquette: >> www.re-wrenches.org/etiquette.htm >> >> Check out or update participant bios: >> www.members.re-wrenches.org >> > _______________________________________________ > List sponsored by Redwood Alliance > > List Address: [email protected] > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://www.mail-archive.com/[email protected]/maillist.html > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > www.members.re-wrenches.org >
_______________________________________________ List sponsored by Redwood Alliance List Address: [email protected] Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/[email protected]/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
