Hi Dana, Sorry for the delay - been on the road. Not sure if this has already been presented / discussed.
The old standby from industrial chargers, is 100% SOC is reached when charge current drops to 2% of capacity (normaly based on 6 or 8 hr rate). Please note, this comes from an era of constant voltage with 8 hrs to recharge then rest the batteries. However, it is an accurate indication of full charge. Time for acid mixing? Now that is a tough one! GC2 & L16's would be close in 30 mins or ~ 10 - 15 mins per 100AH once full charge has been attained however, not sure we can apply to larger format cells. Regards, Jamie >>> "Dana" <d...@solarwork.com> 7/21/2010 7:54 PM >>> As the % of full charge is related to the of degree absorption & gravity [the denser & more charged acid descending, and lighter acid rising] @ what point in the absorption would be prudent to stop charging? I used to cut off the charge on the Trace SW series at 12 âreturn ampsâ, VS. the factory default I think was at 5 amps. This has & continues to work well but I never had anyone really answer this function clearly. Is there a battery manufacturer or wrench that would care to comment on the: The minimum âReturnâ amps to disconnect for a âfullâ charge? OR The time required per 100 AHR after reaching the Absorption point setting for the mix to occur? I realize that battery construction, battery condition, age and temperature and the current power usage will also play into this factor and it may not be a simple answer. Dana Orzel Great Solar Works, Inc E - d...@solarwork.com V - 970.626.5253 F - 970.626.4140 C - 970.209.4076 web - www.solarwork.com Responsible Technologies for Responsible People since 1988" From:re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Mark Frye Sent: Wednesday, July 21, 2010 4:25 PM To: al...@positiveenergysolar.com; 'RE-wrenches' Subject: Re: [RE-wrenches] Propane Generator, Dual Outback Inverters Allen, Can I infer that if you are shutting off the gen before charge rates drop in absorption that you are running only briefly in the absorb phase? Or do your charge currents remain high through out an extended absortion phase? Perhaps you have plenty of PV which you rely upon to bring the batteries up through the absorption phase, once the gen is shut off. I would be interest to learn more about your approach to this. Thanks, Mark Frye Berkeley Solar Electric Systems 303 Redbud Way Nevada City, CA 95959 (530) 401-8024 www.berkeleysolar.com From:re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Allan Sindelar Sent: Wednesday, July 21, 2010 3:17 PM To: re-wrenches@lists.re-wrenches.org Subject: Re: [RE-wrenches] Propane Generator, Dual Outback Inverters The Onan RS20000 shown in the generators article in HP 131 page 98 has performed flawlessly as backup support to an Outback quad-stack of VFX3648s. Differences, however, are that this 20kW gennie charges four inverters, rather than two; the elevation is 6,600 feet for about a 20% output deration; there are no huge loads above charging draw; and the client is aware enough to shut it off before absorption reduces the charge rate - all different conditions than you have described, as the gennie is usually fully loaded and running in balance. Darryl is right about the amount of words necessary. AllanSindelar al...@positiveenergysolar.com ( mailto:al...@positiveenergysolar.com ) NABCEP Certified Photovoltaic Installer EE98J Journeyman Electrician Positive Energy, Inc. 3201 Calle Marie Santa Fe, New Mexico 87507 505 424-1112 www.positiveenergysolar.com No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.851 / Virus Database: 271.1.1/3008 - Release Date: 07/21/10 00:36:00 <br><br>This email and its attachments have been scanned by iConnection E-Mail Firewall for viruses, spam, and malicious content. <br><br>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. %^^%
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