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.

The green batteries are new, they are two 24V 200AH lithium iron phosphate batteries in parallel. I bought these online and and are of very good quality. The yellow batteries are two 12V GSM batteries I purchased at the Yuma Ham Convention in Feb. of 2020, just before everything closed down for Covid. They are tied to the bigger LIfePo4 batteries to make a total of 12.5 KWh of battery storage. They easily run my repeater during the night with plenty of capacity to spare. The power supply on top is a 24V back-up supply should the energy storage drop below 25% charge. It never comes on.

On the top is a fuse block with a 80A fuse and current shunt for the 100A meter. This picture is old, and now the fuse block is on the top green battery. The fuse is the shorter one on the top. The small wires are for the current, voltage and wattage display. I have a switch to toggle my display from reading charge to discharge polarity so I can see how much current is going in or out of the battery. 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.