[RE-wrenches] Small Wh and large LRA

[Warren Lauzon]

The kicker is the large startup, so you may need to use batteries with low internal resistance, such as the Concorde AGM's. You will also have to make sure your cables are good for the max current to avoid any voltage drop which would cause a low voltage shutdown.

Aside from that, just go with around 200-250 AH of battery storage (assuming 12 volts). A pair of golf car size batteries would probably work if they are something like Crown or Trojan.

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Northern Arizona Wind & Sun - Electricity From The Sun Since 1979
Solar Discussion Forum: http://www.wind-sun.com/ForumVB/
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  ----- Original Message ----- 
  From: Mark Dickson 
  To: 'RE-wrenches' 
  Sent: Wednesday, March 17, 2010 2:56 PM
  Subject: [RE-wrenches] Small Wh and large LRA


  Hello Wrenches, 

  I've been asked to design a battery based PV system for a load that has a high start up surge of about 62A @ 115V.  The thing is, once it is running it will only run for ~10 minutes per day at 11A.  So the daily loads are very low.  How do I size a battery bank large enough to handle the large start-up surge, yet reasonable enough to cover the modest daily load?  Is there a rule-of-thumb for this?

   

  Best regards,

   

  Mark Dickson,

  NABCEP Certified Solar PV Installer T

  Oasis Montana Inc.



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