[RE-wrenches] RETURN AMP SETTING

Fri Jul 23 12:47:21 PDT 2010

James – Thank-you! this is a good start and then monitoring the SG after a rest period w/o loads should help determine the time and SOC.

Off to the lab again Igor, we have tests to run.

Thanks,  Dana Orzel

Great Solar Works, Inc

E - dana at 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-bounces at lists.re-wrenches.org [mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of James Surrette
Sent: Friday, July 23, 2010 6:06 AM
To: 'RE-wrenches'
Subject: Re: [RE-wrenches] RETURN AMP SETTING

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" <dana at 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 “return amps”, 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 “Return” amps to disconnect for a “full”  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 - dana at 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-bounces at lists.re-wrenches.org [mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Mark Frye
Sent: Wednesday, July 21, 2010 4:25 PM
To: Allan at 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
 <http://www.berkeleysolar.com/> www.berkeleysolar.com  

  _____  

From:re-wrenches-bounces at lists.re-wrenches.org [mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Allan Sindelar
Sent: Wednesday, July 21, 2010 3:17 PM
To: re-wrenches at 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
Allan <mailto:Allan at positiveenergysolar.com> @positiveenergysolar.com <mailto:Allan at 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 <http://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 

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. %^^% 

No virus found in this incoming message.
Checked by AVG - www.avg.com
Version: 9.0.851 / Virus Database: 271.1.1/3023 - Release Date: 07/23/10 00:36:00

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20100723/4e3dd43d/attachment-0004.html>