[RE-wrenches] Battery idle losses; Sunny Island overhead

[Larry Crutcher, Starlight Solar Power Systems]

Hi Jeff,

1500Wh? That's a 62 watt loss 24/7. That is surprising as it's more than twice what the manufacturer claims; 25 watt with no load or 0.6kWh daily.  However, as loads come on the idle losses quickly diminish as they are overtaken by the load. I have not done any SI jobs but that number, 1.5kWh, concerns me. 

Larry Crutcher
Starlight Solar Power Systems


On Nov 2, 2011, at 4:42 PM, Jeff Irish wrote:

> William,
> 
> I did a 2 year long study on a Sunny Island 5048 grid-intertie battery back-up system and found the SI and batteries used about 1.5kWh per day in "overhead".  The batteries were 8 Concorde AGMs 212Ah C20.  Hope that helps.  
> 
> Jeff Irish, PE
> President
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> and Adirondack Solar
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