<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">HI All,<div class=""><br class=""></div><div class="">I talked to Morningstar today and here is how the tristar work.</div><div class=""><br class=""></div><div class="">To get to the absorb time of 120-150 minutes in CC mode ( + an additional 30 or more if the batteries got below 12.3v nominal the day before)</div><div class="">the controller must get to 15% duty cycle. So for the 60 amp its 9 amps. When it regulates down to this current, it’ll then start the absorb timed cycle. In reality of course its already been there for some time if the duty cycle is anything less than 100%, but thats how MS does it.</div><div class=""><br class=""></div><div class="">I hope this helps,</div><div class="">jay</div><div class=""><br class=""></div><div class="">peltz power</div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><br class=""><div><blockquote type="cite" class=""><div class="">On Sep 11, 2015, at 8:41 AM, Drake <<a href="mailto:drake.chamberlin@redwoodalliance.org" class="">drake.chamberlin@redwoodalliance.org</a>> wrote:</div><br class="Apple-interchange-newline"><div class="">
<div class="">
The batteries are good. We are going to try some custom settings. This CC
works a bit differently than most, and the problem may be in the duty
cycle, IE, how much time the pulses are on vs off. <br class=""><br class="">
At 04:36 PM 9/10/2015, you wrote:<br class="">
<blockquote type="cite" class="cite" cite="">Drake,<br class=""><br class="">
Quote:<i class=""> â...and goes right back to that voltage in the
morning.â<br class="">
</i><br class="">
How quickly does the battery voltage rise to 29.1 in the morning? If the
batteries are sulfated heavily, you may see a very fast rise in voltage
but you will also see a loss of capacity. Batteries in the early stage of
sulfation may have a difficult time reaching the constant voltage
setpoint and remain in bulk charge continuously.<br class=""><br class="">
What is the size of the PV array and battery bank? If the array is too
small for the bank, this is the time of year (less sun hours per day)
that we start to receive complaints about the battery not getting
charged. <br class=""><br class="">
Larry Crutcher<br class="">
Starlight Solar Power Systems<br class=""><br class="">
On Sep 9, 2015, at 5:06 PM, Drake
<<a href="mailto:drake.chamberlin@redwoodalliance.org" class="">
drake.chamberlin@redwoodalliance.org</a>> wrote:<br class=""><br class="">
Hello Wrenches,<br class=""><br class="">
I have a Morningstar PWM 45 that doesn't drop out of absorb. It is set
with dip switches to absorb at 29.2 V and stays constant around 29.1. It
has stayed at 29.1 for several hours straight, and goes right back to
that voltage in the morning. Tech support says the controller is working
correctly. Have any of you seen this, or conversely have you seen the
Morningstar drop into float after a reasonable amount of time?<br class=""><br class="">
Thanks,<br class=""><br class="">
Drake <br class=""><br class="">
<br class="">
<a name="_MailAutoSig" class=""></a>Drake Chamberlin<br class="">
<i class="">Athens Electric LLC<br class="">
OH License 44810<br class="">
CO License 3773<br class="">
NABCEP Certified Solar PV <br class="">
740-448-7328<br class="">
</i><a href="http://athens-electric.com/" class="">http://athens-electric.com/</a>
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