Converting a UPS to a power inverter to power Ham radio equipment HD

I converted this UPS to Charge a external battery. Also installed a Cheap LED voltmeter I got on EBAY so I can monitor the Battery Voltage. I plan to install some additional power wires to power my radios as well as a USB Charge port. I used 8AWG wire to the battery. this battery I am using is 134 AH and is a gel Cell battery