You have plenty of battery capacity to handle your intermittent load so you just really have to deal with the standby load. A 10W solar panel would handle your standby load. There's a handy calculator at tyconpower.com/learning_center I would recommend a small 30W solar panel to take care of standby load and give enough extra capacity to keep the battery bank fully charged. A 12V 5A controller would handle the charging of the batteries and your load. Some prices from beezwaxproducts.com 30W 12V panel $179 12V 5A controller $24.95
Scott -----Original Message----- From: wireless-boun...@wispa.org [mailto:wireless-boun...@wispa.org] On Behalf Of AJ Sent: Friday, January 15, 2010 11:38 AM To: WISPA General List Subject: [WISPA] Solar suggestion for ultra low use site? Thought I'd tap in to the collective intelligence of the WISP group for this question... Looking at setting up a solar powered VHF ham repeater in the middle of a metro area for infill coverage... Site is land locked by ghetto on one side and rail tracks on the other - commercial power is not an option. We have available a dozen or so surplus Alpha 85 amp hour gel cell batteries which test out at roughly 90% capacity (PM swaps)... The first thought was to simply charge up a battery for each event we work in the downtown core, drop by the site and swap out whatever battery is in place.. Not quite the most efficient plan. Our next thought was to place a decent sized array, maybe 300-400 amp hour, then supplement with an off the shelf solar panel or two to maintain a charge... Our equipment consists of an ancient GE MastrII repeater turned down to 25 watts and an NHRC controller. Standby draw is 125 mA, transmit ramps up to about 3.5 amps... Duty cycle is key here - we work perhaps a dozen events a year within the coverage of this repeater for about 4 hours each on about a 10% duty cycle (TX 6 out of every 60 minutes). The rest of the time the repeater sits idle and will not transmit unnecessarily (no IDs or anything unless it's actively in use)... What is out there on the market for a low cost solar site? Thanks! -AJ ---------------------------------------------------------------------------- ---- 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/
