Unlike many commercial devices, this DIY UPS utilises 2 * 12 volt adapter. One for powering the Router and ONU, and the other for charging the batteries. The adapter connected to the female barrel ...

[TechRally] takes advantage of this to create an automatic DC UPS with dual outputs to power a router and modem in the event of a power outage. You can see two videos about the project below.

[Brink] had some issues with the power supply in their apartment, so they set about whipping up a backup power solution to keep their Verizon ONT fiber modem up ... a working UPS setup to keep ...