[RE-wrenches] AGM battery charging, more details

[Starlight Solar, Larry Crutcher]

Re: [RE-wrenches] AGM battery charging, more detailsHugh,

One last point about the Solar Boost IPN product: Once you have programmed the 2512iX charge controller from the IPN Pro, the controller retains the information and can be installed as a stand-alone unit. That means you can have a custom programmed charge controller for just a little more than the Tristar you are considering.

I don't get your final comment. The group has shared a vast amount of information in this thread. If you review all that has been said, I think you will be able to make the right choice for your customer.

Larry Crutcher
Starlight Solar Power Systems
www.starlightsolar.com
928-342-9103


  ----- Original Message ----- 
  From: Hugh 
  To: RE-wrenches 
  Sent: Wednesday, April 27, 2011 10:59 PM
  Subject: Re: [RE-wrenches] AGM battery charging, more details


  At 22:38 -0500 26/4/11, William Dorsett wrote:


    OK, I can see how you could input the amphr capacity of a given set of new batteries, but would someone explain how a controller which counts amps can adjust as the battery bank ages? As the capacity of the bank drops over time, and this varies by different manufacturers, it still seems that a controller which measures voltage would track the SOC of the bank better than current counting.



  Keeping track of SOC by counting Ah is a challenge in itself, but the battery manufacturers' instructions don't require this.  Fullriver and Surrette require the you make a transition between Absorption and Float charge regimes/stages at a certain point where the charging current drops to a given level (although the Rolls FAQ is puzzling in its wording there - suggesting that you can charge at 0.25 x C20 indefinitely!).  Most stand alone RE system controllers do not possess the ability to monitor the battery current, so they cannot follow these instructions.  This is my concern. 


    At 10:54 -0700 26/4/11, Rick Cullen - Blue Sky Energy, Inc. wrote: 
      There has been some discussion in the past few days regarding AGM batteries and charge control switching to Float based on net battery charge current matched to battery size and that our IPN-ProRemote product can provide this.


  Rick's Blue Sky product fits the bill but it seems expensive in the context of very small systems.  Phil Smith of Barden Batteries in the UK has told me that a correctly programmed Tristar controller will do a good job even though it does not 'know' the battery current.  This is good news.


  I am still deeply puzzled about sealed batteries as I learn that you must not make them gas but you have to be sure to charge them well (like any other lead acid battery) or they will fail prematurely.  That's why I would like to be able to fit controllers that monitor the battery current and use this to determine the transition to a float charge. 


  Maybe it would help if somebody told me what sort of charging would actually damage a sealed battery.  Then I would simply charge them as hard as the wind/sun allows while avoiding doing that.
-- 
Hugh Piggott

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

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