Solar Power for Repeater
and Battery Backup Power

This is my rack-mounted radio Repeater. As you can see, the power cord is un-plugged from AC, but what you don’t see is the 24V feed from the other side of the wall.

These are the two 12V 125AH batteries in series to make 24V. I bought these at the Yuma Ham Convention in Feb. of 2020, just before everything closed down for Covid. They easily run my repeater during the night with plenty of capacity to spare.

On the top is a fuse block with a 80A fuse and current shunt for the 100A meter. I have a switch to toggle from charge to discharge polarity so I can see how much current is going in or out of the battery. The fuse is the shorter one on the top. The small wires are for the current, voltage and wattage display. All high capacity runs are using two 8 gauge wires in parallel, safely providing up to 80 Amps of current. The 80Amp fuse limits the system to just over 1900 watts output.

You can see the battery terminals and the series jumper. Note the two 8 gauge wires to safely handle high current

This is the solar controller, battery monitor and AC inverter.  My RF power meter for the repeater is on top. The monitor display shows me the battery capacity in AH that I have left, real time wattage, current and voltage. The solar controller only shows battery voltage, and the inverter shows the AC voltage. This is a 2500 Watt inverter, but the 80A fuse will limit it to about 1900 Watts. The buck converter on the side is set for 5.2V output for my Raspberry Pi. The top converter (not hooked up in this photo) is now set to 12V for my DSL modem, Netgear router, and an Ethernet switch in my office. The 5V buck converter now
powers the qso.com and n7okn.com server (now on a Raspberry Pi 4), my PBX, and repeater controller. The switch on the right turns on or off the 24V bus that feeds everything.

These are two 290 Watt solar panels. They are wired in parallel and yield about 500 watts with direct sunlight. It easily runs the repeater while charging the battery at the same time.