As you know, many/most transceivers want a 13.8 V input – charging voltage of a standard NiMH battery. This does not really match the modern world of LiIon/LiPo chemistry, on which a single cell can have between 3.3 to 4.2V – meaning an 3S pack would be 9.9 to 12.6V (too low) and an 4S pack would be 13.2 to 16.8V (kinda high).
The Xiegu G90 accepts these voltages: Operating voltage range: 10.5-16.5 V DC (voltage must be in 13.8-15V if need 20W) according to the product pages and this product review. However, I don’t like running things to the limit (good for longevity). I also don’t have any 4S LiPos, but have a few 2S and 3S LiPos from ahem another hobby, so here goes.
Got an Aliexpress step-up converter lying around, so I printed this case with two modified panels in order to fit a different type of voltmeter and have two outputs, added an automotive blade fuse (can’t never be too safe !), added the XT60 connectors because they’re the best connectors in terms of value over price and here it is: a box that outputs 13.8V no matter what’s connected as an input, while also displaying the input voltage (you do not want to run a LiPo below 3.2V/cell).
PS: yes, I’m not a big fan of hot glue, but it works.