How irritating isn't it when you are staying at a hotel and the WiFi is just lousy. With a WiFi extender you can improve the conditions, but the ones I have seen require a mains outlet, which is not always available. I decided to rebuild a low cost repeater for battery power. And the battery is the one used as backup for the phones, Now I hope that the Bali Internet will provide us with good Netflix connection.
Step 1: The Components
You need an extender; I use the D-Link DAP-1620 WiFi range Extender (or the extender of your choice, hopefully with internal 5V power supply, otherwise you have to fix another battery solution)
A standard USB 5V charging battery
A cable with a USB-A connector
A new lid
Male and female charger connectors
Step 2: Disassembly
Unscrew the three screws and, using a thin screwdriver, carefully separate the lid from the bottom. There are four "hook" that holds the things together. Remove the AC adapter part.
The low voltage power is supplied by the four pins seen at the back.
Step 3: Make a Connection
Get some kind of two pin connector that fits in two of the holes in the black connector on the pc-board (seen in picture no 2). I had one with five pins that I could use.
Solder two wires to the connector. Black is ground, red is +5 volts.
Step 4: A New Lid
Get some kind of plastic lid. Drill three holes for the screws and one hole for the charger connector. Another option is to solder the USB cable directly to the internal male 5V connector (my brown angular connector)
Step 5: Connect the Connector
Put the connector in the lid and solder the power wires from the internal angular connector.
Step 6: Fix a Cable
Get an old (or new) USB cable with one USB-A connector. Strip the wires and solder a charger connector to the USB-cable
Step 7: The Completed Exender
Connect the USB battery with the cable to the extender and start configuring it. To be on the save side, before you apply power and assemble everything, with the internal connector disconnected, connect it to the battery and confirm that it is correctly soldered, with ground at the edge of the board and +5 V on the other pin.