Rod - I would suggest a short conversation with Mike Bryce, WB8VGE. In addition to the Heathkit Shop, Mike contributed chapters and sections to the new ARRL publication Emergency Power. He can discuss your "total system" from current demands, to expected current generating capabilties of the solar panel you selected. http://www.theheathkitshop.com/ Mike's "day job" is with Sunlight Energy Systems in North Lawrence, Ohio http://www.seslogic.com/Site%208/Products.html I agree with earlier responses: 1. Get a proper battery charging unit - for the solar panel - "smart chargers" are now very inexpensive and can properly manage your batteries. 2. You should ONLY be using deep cycle cells - used in marine industry and Uniteruptable power systems -- DO NOT stop at your local automotive dealer -- car/truck batteries are totally inapprorpiate for this application. The size and capacity fo the cells must be matched to your load AND to the expected solar panel charging ability. (This is the "teeter totter" part of the design). Greg, w9gb ----------------------- Posted by: "[EMAIL PROTECTED]" [EMAIL PROTECTED] selah_102 Sun Dec 3, 2006 9:12 am (PST) Here is the info on the system and my question:
Let me tell you about what I have: One 110 watt panel, one 115 watt panel, one 400 watt wind gen, two bridge rectifiers, two 1500 cca batteries, two GM300 radios, one IDer, one NHRC4 DTMF controller, one dump load circuit with two dump lines, four 300 watt 1.2 ohm resisters for the dump lines. Now when the repeater is turned on, it draws one amp and in tx it draws about 7 amps. For isolation for the panels I have one 85 amp diode on the plus and negative lines to keep the wind gen from energizing the panels with up to 41 amps. Now for some reason the panels and the wind gen are not keeping the two batteries charged. Not sure why. The panels are set for the winter setting for my location. I was at the site today to test the batteries, because the repeater was not working. Both batteries tested at 7.81 volts and the panels tested at 8 volts at about 4 pm. The sun was almost down. We pulled the one fuse that all the voltage goes thru and I will go up there tomorrow and check the voltage on the batteries in sun light. The current from the batteries can not back feed to the wind gen due to the bridge rectifiers (the wind gen produces ac). The wind gen can not back feed to the panels due to the 84 amp diodes on the positive and negative lines. The two batteries are not isolated from each other. On November 18 the batteries tested at 12.79, repeater was turned on. We took the batteries down to about 11.9 using an inverter with 110 volt ac test equepment plugged in. On November 24 the voltage was 11.27. On Novemner 28 the voltage was about 10 volts. I turned the repeater off (tx radio only) remotely. Then you have all the information I stated above. I will be going up there today after church. >From what all I have told you, do you see anything why the two panels a lone should not keep the batteries up? The repeater has been turned off since last Tuesday morning. But yet the batteries are still being drained. In the turned off mode, I mean the tx radio is turned off, but everything else is still on. The last three days have been sunny day here in Yakima, with no wind for the wind gen. I am at a loss of what is going on; the batteries are getting weaker. Why? Rod
