[RE-wrenches] AGM battery charging, more details

Starlight Solar, Larry Crutcher larry at starlightsolar.com
Thu Apr 28 17:46:09 PDT 2011


Yes Larry, a starting battery. I'm feel quite sure it is designed for constant voltage. We were discussing the deep cycle AGM battery. 
I have seen batteries charged incorrectly and survive. But why take the chance having a meltdown or worse? 

Perhaps this will help some understand the importance of proper voltage: http://www.cdtechno.com/custserv/pdf/7944.pdf
Larry
  ----- Original Message ----- 
  From: wirewiz at gmail.com 
  To: RE-wrenches 
  Sent: Thursday, April 28, 2011 4:00 PM
  Subject: Re: [RE-wrenches] AGM battery charging, more details


  I have been prolonging the temp comp. absorption voltage (no current) on start batteries in boats for many years without any problems.


  Larry Liesner
  Wirewiz
  31 Lincoln St
  Westport, CT 06880
  Phone: 203-644-2404
  wirewiz at gmail.com
  www.wire-wiz.com







  On Apr 28, 2011, at 5:52 PM, Starlight Solar, Larry Crutcher wrote:


    ...."Until now"?.....
    For proper VRLA battery charging, once it is full, you MUST reduce the voltage. It does not matter that you are opportunity charging. What if your turbine is making power 24/7? The voltage will still need to be reduced after a few hours or have a fixed voltage setting. I don't think you are ungrateful but again I encourage you to re-read this thread and the manufacturers instructions. It's all there.

    Larry 
      ----- Original Message -----
      From: Hugh
      To: RE-wrenches
      Sent: Thursday, April 28, 2011 2:04 PM
      Subject: Re: [RE-wrenches] AGM battery charging, more details


      I am sorry if i seem ungrateful for the many useful ideas that have been voiced.  I suppose I just like to try to oversimplify things.  At present my over-simplification is to say that, for opportunity charging, the only thing that really matters is not to exceed the temperature-compensated absorption voltage.    Until now I had imagined that it was dangerous to prolong the absorption voltage stage.  But maybe float is not so important as making sure that the battery gets enough charge to prevent premature failure.  By the time the charging current has dropped to the transition current level it is too low to do any damage and can be prolonged indefinitely (until wind and sun stop anyway).  This would not work in a grid connected situation, but seems to fit for mine.  I am sure you guys will point out if I have got this wrong.
-- 
Hugh Piggott

      Scoraig
      http://www.scoraigwind.co.uk
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