A low-cost uninterruptible power supply for your broadband Wi-Fi router using a USB battery bank and a 5 V to 12 V DC boost cable (~1 EUR from AliExpress). Keeps your router running through short power outages so you don't lose calls or downloads while the backup generator kicks in.
The boost cable
A USB 5 V to DC 12 V step-up cable with a 2.1 × 5.5 mm barrel connector — sold for about 1 EUR including shipping.
USB 5 V to 12 V boost cable — the black housing contains an MT3068 converter PCB.
Inside the housing — MT3068-based boost converter.
This cable provides up to ~8 W output, which is enough for a standard broadband router. If your router draws more than 8 W, look for a higher-capacity boost cable.
Setup
Connect a 5 V DC adapter to the battery bank's charging port. The battery bank's USB output feeds the boost cable, which powers the router at 12 V.
Complete setup — 5 V adapter charges the battery bank, which powers the router through the boost cable.
Backup duration depends on the battery bank capacity. A smaller battery handles short outages (a few minutes while a generator starts); a larger one extends runtime for longer outages.
