I'd want to see that graph dropping off sooner, perhaps finishing the charging by about 1pm. Is your charge controller a 3 stage charger (bulk, absorb, float) or some approximation? It looks like your batteries might just be getting full when the sun is going down. Was that a clear sky day? How long has that site been in service? Are you getting a good lifespan out of the batteries?
Greg On Aug 27, 2009, at 1:22 AM, Matt Larsen - Lists wrote: > Here is the graph straight from the charge monitor for our solar > panels, > to give you an idea what the charging pattern looks like. This is > for > a pair of 60w panels. > > http://www.thelar.com/gallery2/v/Wireless/Hogback/ > graph_image1.png.html > > Matt Larsen > vistabeam.com > > Christopher Erickson wrote: >> First, the Sun never shines 24 hours in a day unless you are above >> the Arctic circle. And even then, that only happens for a few days >> of the year. >> >> Second, there isn't much charging going on when the Sun is near the >> horizon, which is most of the time when in Northern latitudes. >> >> For example, an 80 watt panel will NEVER output 80 watts in >> Anchorage, >> Alaska because even at solar noon in the summer, the Sun is only >> around 60 degrees up in the sky. And below about 25 degrees, there >> isn't any charging going on at all. >> >> So anyway think of an amperage sine wave that builds up in the >> morning, >> peaks at solar noon and then diminishes in the afternoon. >> >> The math is more complicated than it first appears. >> >> "My advice is always free and worth every penny!" >> >> -Christopher Erickson >> Network Design Engineer >> 5432 E. Northern Lights Blvd., Suite 529 >> Anchorage, AK 99508 >> >> >> >> >>> -----Original Message----- >>> From: wireless-boun...@wispa.org [mailto:wireless- >>> boun...@wispa.org]on >>> Behalf Of Mike >>> Sent: Wednesday, August 26, 2009 9:06 PM >>> To: WISPA General List >>> Subject: Re: [WISPA] solar site >>> >>> >>> I'm not sure I buy into your math. If I have a repeater site that >>> is >>> pulling 1A @ 12V, then it is consuming something like 12W, right? >>> If >>> I have 60W of solar panel (2 toys) then when conditions are optimal, >>> I have 48W left over to charge the battery. >>> >>> Lets say I am REALLY north, and the panels are only producing >>> 45W. I >>> still am consuming 12W with the radios, and have 33W left over to >>> charge the battery. If I have an 800AH battery 24 Hours of sun will >>> run the radios AND fully charge the battery. If the sun shines 24 >>> hours out of 33.3 days, I will stay ahead of the curve and the >>> battery will stay charged. >>> >>> No sun for 33.3 days and my 800AH battery will finally die. I NEVER >>> see those conditions here in the midwest. I'll still maintain you >>> can do a repeater site for $500 in solar power costs and if you >>> monitor battery condition it will work just fine. >>> >>> At 09:54 PM 8/26/2009, you wrote: >>> >>>> Here in the north, I wouldn't bother with anything less than 100w >>>> of >>>> panel. >>>> >>> >>> >>> ---------------------------------------------------------------------- >>> ---------- >>> WISPA Wants You! Join today! >>> http://signup.wispa.org/ >>> ---------------------------------------------------------------------- >>> ---------- >>> >>> WISPA Wireless List: wireless@wispa.org >>> >>> Subscribe/Unsubscribe: >>> http://lists.wispa.org/mailman/listinfo/wireless >>> >>> Archives: http://lists.wispa.org/pipermail/wireless/ >>> >> >> >> -------------------------------------------------------------------------------- >> WISPA Wants You! Join today! >> http://signup.wispa.org/ >> -------------------------------------------------------------------------------- >> >> WISPA Wireless List: wireless@wispa.org >> >> Subscribe/Unsubscribe: >> http://lists.wispa.org/mailman/listinfo/wireless >> >> Archives: http://lists.wispa.org/pipermail/wireless/ >> >> > > > > -------------------------------------------------------------------------------- > WISPA Wants You! Join today! > http://signup.wispa.org/ > -------------------------------------------------------------------------------- > > WISPA Wireless List: wireless@wispa.org > > Subscribe/Unsubscribe: > http://lists.wispa.org/mailman/listinfo/wireless > > Archives: http://lists.wispa.org/pipermail/wireless/ -------------------------------------------------------------------------------- WISPA Wants You! Join today! http://signup.wispa.org/ -------------------------------------------------------------------------------- WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
