Here are a few of relevant links http://www.ccis.com/home/mnemeth/12volt/12volt.htm http://www.uuhome.de/william.darden/ http://www.batteryuniversity.com/ I have an RV that was built in 1999 that has the original vehical battery installed. I have been through many batteries in the living section. Deep cycle batteries are not as available as Marine batteries, so that may be part of my problem. John Ferrell W8CCW "My Competition is not my enemy" http://DixieNC.US ----- Original Message ----- From: "Robert A LaBudde" To: "Microcontroller discussion list - Public." Sent: Monday, August 21, 2006 12:54 AM Subject: Re: [EE] Battery (SLA) deep cycle damage offset by immediate tricklecharge? > At 11:24 PM 8/20/2006, James wrote: >>I have a question for anyone out there who REALLY understands lead acid >>battery chemistry and operation or who has a lot of experience with it. >> >>The commonly available wisdom is that lead acid batteries die after so >>many >>cycles because they can not be left uncharged (or partially uncharged) >>without the chemistry eating up the insides and killing the battery. LA >>batteries work will in cars because as soon as they are discharged, and >>usually not discharged very much, they are immediately recharged again. >>Running a car battery down to nothing (leaving your lights on) and then >>letting it sit for a day will render it useless after just a few such >>cycles. >> >>My question is this: Is it the total time the battery is less than fully >>charged (the integral of the discharge amount over time) that kills it, or >>is it being left, discharged, with nothing coming or going for some time >>that does the damage? >> > > I'm no expert on this topic, but I believe that keeping the battery at > full > voltage prevents the degradation mechanism from occurring. > > This would imply that when the voltage drops to a critical level, > degradation (growth of sulfate "coral reef" on the electrodes) starts. > This > must take time to progress, so the time and temperature must be important > factors as well as the reduced voltage. > > The charge itself reverse polarizes the electrodes, so I would think that > this would also stop sulfonation(?). > > So my (guess) conclusion would be that an immediate charge after deep > discharge would be protective to some extent. > > My brother (Edward V. LaBudde), who's more expert on this subject, wrote a > posting to one of the desulfonator bulletin boards. I've attached a PDF > file of this, as portions of it may be relevant to the issue. > -------------------------------------------------------------------------------- > ================================================================ > Robert A. LaBudde, PhD, PAS, Dpl. ACAFS e-mail: ral@lcfltd.com > Least Cost Formulations, Ltd. URL: http://lcfltd.com/ > 824 Timberlake Drive Tel: 757-467-0954 > Virginia Beach, VA 23464-3239 Fax: 757-467-2947 > > "Vere scire est per causas scire" > ================================================================ -------------------------------------------------------------------------------- > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist