Rod, I believe that a good solar charge controller is needed here, to properly manage the battery charging and protection. Lose the wind generator, the bridge rectifiers, and the resistors. Connect the 115 watt solar panel directly to the input terminals of the solar charge controller. Do not ground either of these wires. Connect the battery terminals of the solar charge controller directly to the battery. Do not ground either of these wires. Connect the load terminals of the solar charge controller directly to the common DC input terminals of the radios and controller. Ground the negative wire at the radios- which are already grounded internally and through the antenna feedline shield.
Batteries intended for solar or wind power applications do not have CCA (Cold Cranking Amperes) rating; they are always rated in AH (Ampere Hours). If you are using vehicular wet-cell batteries, that may be part of the problem, since car batteries do not do well in deep-cycle applications. Use AGM sealed lead-acid batteries for solar systems. A solar charge controller that is ideal for your system costs less than what you spent for your large load resistors. You do not need resistors in a solar power system. A solar charge controller handles voltage regulation and battery charge control without any external components. Since you have dissimilar solar panels, you first need to balance their outputs if you want to run them in parallel. The procedure for doing that is too lengthy to go into here, but you can use two Schottky diodes in the positive leads only to safely run two panels in parallel. Schottky diodes have extremely low forward voltage drop that is almost independent of current. If the two panels are identical and from the same lot, it is usually okay to hook them directly in parallel. 73, Eric Lemmon WB6FLY -----Original Message----- From: [email protected] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Sunday, December 03, 2006 9:10 AM To: [email protected] Cc: [EMAIL PROTECTED] Subject: [Repeater-Builder] GR300 on Solar 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
