Retransmitted as Yahoo did not like me using an underscore. Picky-picky, picky. rb Bob: Thanks for a very thorough and well-stated response. The knowledge base of this Club never ceases to amaze me. Perhaps Tim's rule of thumb is really 1/2 % per day. That is more in line with your data. Rich Barber Brentwood, CA C-300 Bob Jasinski wrote: >Tim, > >You mentioned, "The rule of thumb that was used was that a lead/acid battery >looses half >its remaining charge every 24 hours". > >I afraid I have to disagree with this. Lead acid batteries do self >discharge, but not nearly that fast. Just to clarify what we are referring >to, we are describing a battery that starts out fully charged, with no load, >as if you charged it fully and disconnected it from the circuit to assure a >no load condition. > >According to the Battery Council International (BCI) self discharge @ 80 >degrees F equals about .001 Specific Gravity (S.G.) per day. A typical wet >car battery starts out full charge at 1.265 S.G., and is considered fully >discharged at 1.120 S.G. That would equate to a fully discharged state >within 145 days. That is about .69% per day discharge. > >The amount of self-discharge is much slower at lower temperatures, and >higher with higher temperatures. Also, the lower amount of antimony in the >grid alloy the less amount of self discharge, that is why "low maintenance" >and "sealed" batteries (which have little or no antimony) have a longer >shelf life, but are less likely to accept a charge once they do go flat. > >I have worked for GNB, Exide and C&D battery companies over a 20 year period >and have been involved in battery applications pertaining to UPS, Telecom, >Motive Power and Automotive uses during that time. My access to battery >engineers and designers have allowed me an opportunity to develop a deeper >understanding of what makes these black boxes "tick". > >Bob J >Danville, CA > ------------------------ Yahoo! Groups Sponsor --------------------~--> Yahoo! Autos. Everything you need to know about buying or selling a car. FREE Quotes, 360° Tours, Research, Blue Book, Compare Vehicles, Buy Used http://us.click.yahoo.com/kEZsdA/bwnGAA/YiGOAA/8LmulB/TM --------------------------------------------------------------------~-> To send a message to this group, send an email to: Chrysler300@xxxxxxxxxxxxxxx For list server instructions, go to http://www.chrysler300club.com/yahoolist/inst.htm Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Chrysler300/ <*> To unsubscribe from this group, send an email to: Chrysler300-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/