[RE-wrenches] Higher LVR to force full re-charge in small OGPV systems

[Exeltech]

Jay,

You surmize correctly on both points.  12.0V equates to ~50% DOD.  The LVD point should be higher.  The actual value depends somewhat on the battery type and ambient temperature, but under lightly loaded conditions (e.g. C/30), the LVD should be adjusted for around 12.4Vdc to keep the discharge to 20% or less.

Dan

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On Thu, 1/2/14, jay peltz <jay at asis.com> wrote:

 Subject: Re: [RE-wrenches] Higher LVR to force full re-charge in small OGPV systems
 To: "RE-wrenches" <re-wrenches at lists.re-wrenches.org>
 Date: Thursday, January 2, 2014, 7:37 PM
 
Hi All,

I've been wondering about the LVD set point for this project and I'm asking what you all think.
So far 12.0v has been chosen for the LVD and 13.8 LVR.

But IMHO as the PV might do 15-20% at best avg per day, I got to thinking that at 12v, its around 40-50% SOC, so it might be the system could be off for a few days as it recharges.

If the LVD was higher then it would bounce around at at higher SOC  with a lesser chance of off for days and hopefully at least some lights every day.

curious what you think,

thanks,

jay