<html><head><style type="text/css"><!-- DIV {margin:0px;} --></style></head><body><div style="font-family:times new roman, new york, times, serif;font-size:12pt"><DIV>HI Hugh and all</DIV>
<DIV>As Hugh knows the Outback FNDC was meant for such operation, Apollo can track the SOC but can not control off SOC. </DIV>
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<B><SPAN style="FONT-WEIGHT: bold">From:</SPAN></B> Hugh <hugh@scoraigwind.co.uk><BR><B><SPAN style="FONT-WEIGHT: bold">To:</SPAN></B> Allan@positiveenergysolar.com<BR><B><SPAN style="FONT-WEIGHT: bold">Cc:</SPAN></B> RE-wrenches <re-wrenches@lists.re-wrenches.org><BR><B><SPAN style="FONT-WEIGHT: bold">Sent:</SPAN></B> Mon, April 25, 2011 1:27:00 AM<BR><B><SPAN style="FONT-WEIGHT: bold">Subject:</SPAN></B> Re: [RE-wrenches] AGM battery charging, more details<BR></FONT><BR>At 15:30 -0600 24/4/11, Allan Sindelar wrote:<BR>> The Solar Boost products actually used an external shunt option, tying to the Kelvin terminals on the shunt to measure current and allow compensatory current; a dip switch controlled internal/external sensing. Modern digital controllers apparently rely solely on voltage variations.<BR><BR>Thanks Allan,<BR><BR>So most modern controllers cannot sense the battery current and therefore cannot use this as a cue to switch to
floating the battery. I confess that I had never heard of the Solar Boost external shunt but since most of my systems have an element of wind and/or hydro this would not be an option for me. Without this external shunt, a controller is not going to know the charging current (since part of the current will be going to the load). Without knowing the current, how can you do a proper job of switching to float and avoiding drying out the battery?<BR><BR>I don't understand how people can use sealed batteries successfully on RE systems. I avoid them when I can and I usually set the absorption voltage too low, for safety, if I do have to. But I am keen to learn about a successful approach that does charge the battery properly without drying it out.<BR>-- Hugh Piggott<BR><BR>Scoraig<BR>http://www.scoraigwind.co.uk<BR>_______________________________________________<BR>List sponsored by Home Power magazine<BR><BR>List Address: <A
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