[RE-wrenches] Array/battery relationship (WAS Battery Watt hours FLA VS Iron Edison Batteries)

[Ray Walters]

I agree, 2 to 3 days works pretty well, but I double check that we are 
within the recommended minimum and max charge rates for the battery.
I found, as Alan mentioned, that many old school designs did not meet 
the minimum charge rates, and resulted in sulfated batteries. Like wise 
I've come across some recent systems by the new crop of solar 
installers, that had grossly undersized batteries.   They were 
constantly being over charged, and also couldn't supply enough current 
to operate the inverter at rated power.
Aren't those cute?  100 AH just isn't enough battery for a 4 kW 
inverter, though.

R.Ray Walters
CTO, Solarray, Inc
Nabcep Certified PV Installer,
Licensed Master Electrician
Solar Design Engineer
303 505-8760

On 10/15/2016 9:02 AM, Dan Fink wrote:
> My design philosophy these days matches yours 100%, Allen. Because of 
> cheap PV, and FLA batteries still stuck in the 1910s. It was a 
> different story (not too many years ago!) when a good deal on PV was 
> $5 a watt.......
>
> Dan Fink
> Adjunct Professor of Solar Energy Technology, Ecotech Institute
> IREC Certified Instructor™ for:
> ~ PV Installation Professional
> ~ Small Wind Installer
> Executive Director, Buckville Energy
> NABCEP Registered Continuing Education Providers™
> 970.672.4342 <tel:970.672.4342>
>
>
> On Fri, Oct 14, 2016 at 3:55 PM, Allan Sindelar 
> <allan at sindelarsolar.com <mailto:allan at sindelarsolar.com>> wrote:
>
>     Dana (and I'm curious if others agree),
>     I used to work with 4-5 days of storage, back with modules were
>     expensive and batteries were relatively cheap. As in recent years
>     these two have reversed - modules are cheap and batteries are dear
>     - my fundamental design approach has changed. I now design around
>     2-3 days of storage with a larger array, as long as there's a
>     backup generator in the system. I size to at least 100% of the
>     projected winter average daily load.
>
>     The batteries recharge more quickly, including on partly cloudy
>     days between storms. They spend more of their time full, thus
>     keeping them happier and giving them as much or more life, even
>     with more and deeper cycling. FLAs are easier to EQ, given the
>     hotter charge rate. And the customer spends less.
>
>     You used to live in SW Colorado, a similar sunny winter climate.
>     Is it the same in Idaho where you live now?
>     Allan
>
>     *Allan Sindelar*
>     allan at sindelarsolar.com <mailto:allan at sindelarsolar.com>
>     NABCEP Certified PV Installation Professional
>     NABCEP Certified Technical Sales Professional
>     New Mexico EE98J Journeyman Electrician
>     Founder (Retired), Positive Energy, Inc.
>     *505 780-2738 <tel:505%20780-2738> cell*
>
>
>
>
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