APC - Back-UPS Connect 84VA Battery Back-Up System | $30 | Amazon

Update: Sold out, sorry!

If you use a desktop computer, a good UPS battery backup will keep it running without any interruption in the event of a power outage, which means you won’t lose any unsaved work. But even if you’re a laptop user, this could still run lamps, your router and modem, or any other low-draw devices until the power comes back on. This particular model even includes some USB ports for charging your mobile devices.