From: muratlanne@gmail.com   
      
    wrote in message   
   news:11a3aetin2kaetfig7b7a19ob19ti8oo6l@4ax.com...   
   > On Sun, 31 Mar 2019 10:15:17 -0400, "Jim Wilkins"   
   >  wrote:   
   >>...   
   >>   
   >   
   > I do check the specific gravity of the few flooded batteries I have   
   > and I record that.  Having sealed AGMs as the primary battery bank   
   > is   
   > nice because there is no acid or hydrogen to deal with and they can   
   > live in "people space" but you do lose the ability to check a key   
   > parameter - the specific gravity.   
      
   I keep looking for good cheap AGMs. I don't have a source for decent   
   used ones above 12V,18AH, and according to data sheet DOD-vs-life   
   graphs even the cheaper flooded batteries cost more in depreciation   
   than they save from free electricity, so my system is for power outage   
   backup where storage life matters more. The battery makers admit that   
   a -maintained- flooded battery can last longer than a   
   maintenance-proof AGM.   
      
   Week-long outages are rare enough here that I don't think the lifespan   
   loss from operating below full charge during one is that significant,   
   as long as the battery is equalized afterwards. Power wheelchair   
   batteries suffer the same problem of a too-brief indoor charge while   
   the owner sleeps and may last a year or two.   
   https://batteryguy.com/kb/knowledge-base/how-long-should-an-elec   
   ric-wheelchairscooter-battery-last/   
   "An 8 hour overnight charge is usually not enough to return the   
   battery to fully charged."   
   "Golf Carts which use a similar design to electric wheelchairs and   
   scooters are known for using the same batteries, but achieving total   
   life spans up to twice as long."   
      
   Don't ask me how he expects the disabled owner to swap heavy   
   batteries.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)