First post on here, have spent some time reading through various threads.
I am building a portable radio box for outings and am wanting something like a UPS setup but on the +12 Volt level.
The box will have an internal Battery, and an external Input.
I want to draw from the external source when its safe (voltage in range), saving the internal charge.
My thought is to use a mosfet setup to switch the Sources. Ideally i'd like to have switching to be fast enough to remain on without interrupt.
I do intend on putting a current shunt in to monitor and cut off the load if the current rises to high.
I am slowly learning code, but am more concerned if my idea will work.
If it works as I think it should, i could use a battery on the input until its low, and the Controller flips to internal, the i could plug in a second external battery and the controller would see it and return to the input feeding the load.
I am also looking at making a charger to use input voltage to step up and charge the internal battery, But that is a project for later.
I know i will need Voltage dividers, and once the tested solution is working i will be ordering some tight tolerance parts to build the final unit. For now i have 1/2 Watt, 5% resistors to use.
I have a Nano that i have made show a variable voltage on the 20x4 LCD, I have some relays and shunts but have not gotten that far.
Nor have i started on any form of code for the project.
Just looking for thoughts and input for now