David, It may be worthwhile to realize that the BatteryUniversity.com website is not run by a University if you would take the name literally - but as can be expected, by a company with an interest in battery analyzers that was founded by an inventor. See the "About us" page which has at the bottom: "Learning the basics about batteries - sponsored by Cadex Electronics Inc." "© 2013 Isidor Buchmann."
So, it sounds like these web pages are made by a person who should be at least somewhat familiar with the topic of rechargeable batteries, seeing that he has founded a company making battery analyzers and rejuvenators, but that latter concept has been contended by many here and in the website I could not find that he has any formal background in battery technology, so it could just as well be a company that had a lucky strike by marketing well and find big customers, without necessarily completely understanding what they are doing. The info that you quoted (overly generalizing from some of the behavior of particular contruction (flooded golf cart batteries) and mis-labeling that as valid for all lead-acid batteries...) certainly supports the impression that they are more interested in marketing than in being accurate about their battery info... Cor van de Water Chief Scientist Proxim Wireless Corporation http://www.proxim.com Email: [email protected] Private: http://www.cvandewater.com Skype: cor_van_de_water XoIP: +31877841130 Tel: +1 408 383 7626 Tel: +91 (040)23117400 x203 -----Original Message----- From: [email protected] on behalf of EVDL Administrator Sent: Sun 2/3/2013 10:36 PM To: [email protected] Subject: [EVDL] Battery University? Someone posted a link to batteryuniversity.com on the Elec-trak list. I glanced at the site and the first page I checked was this one http://batteryuniversity.com/learn/article/charging_the_lead_acid_battery where it says "Lead acid is sluggish and cannot be charged as quickly as other battery systems." News to me! From what I know, as long as you stay below 80% SOC and monitor temperature, you can charge an AGM battery about as fast as you can discharge it - and that's easily thousands of amps. Sluggish? I don't think so. The same page also describes a basic 3-stage algorithm (bulk, finish, float) as if it were the only way to charge a lead battery. They ignore constant voltage charging and DV/DT. Finally, this page's author states that "Measuring the open circuit voltage (OCV) while in storage provides a reliable indication as to the state-of- charge of the battery." Not in my experience, and not according to Nawaz Qureshi, Vice President of Engineering, USBMC, who says "Voltage is not an accurate indicator of state of charge." http://evdl.org/pages/socvolts.html If I'm barely qualified to judge what's written there about lead batteries, I'm TOTALLY unqualified to judge the value of their documentation on lithium batteries. What say you battery experts? How much of batteryuniversity.com is useful, and how much is bogus? David Roden EVDL Administrator http://www.evdl.org/ _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
