Solar powered router

Idea

Solar- and car-battery-powered router mounted on handcart.

The idea of solar powered wifi routers has been discussed and also implemented many times as there are numerous situations where you cannot (or do not want to) rely on wired power supply, for example:

Nodes in nature (rural areas, parks, gardens).
Power blackouts.
Rooftops or other places that are hard-to-reach with cables.
Developing countries where wired power supply is unavailable or power outages occur frequently.
Protests or other gatherings where mobility or independence from centralized (and thus easy to shut down) power supply is important.

If no internet uplink (or mesh node with connection to a uplink-node) is within wifi-range, a 3G/UMTS/LTE USB device can be used.

A working setup

This is a setup which has been tested by Andrenarchy. Thanks to a car battery this setup should keep the router alive for about 3-4 days without sunlight. The used charge controller monitors the status of the car battery and disconnects the router before the battery gets damaged due to deep discharge. Likewise the battery is protected against overcharge. The 50W solar panel should deliver enough energy to allow all year (day and night) operation under average weather conditions in Germany -- of course this highly depends on the latitude and weather conditions of your location. The Freifunk-MPP-Tracker might be helpful in maximizing power extraction under all conditions (variable amount of sunlight falling on the solar panels). If you only need the router for 3-4 days and if you can recharge the car battery in another way, then you can simply omit the solar panel (which is the most expensive part).

Components

Description	Component	Price	Further information
WiFi router	TP-Link WR1043ND	~40 EUR	12V, 0.3A (wifi load), USB2.0 port, compare TP-LINK and openwrt specifications
solar panel	Goliath AV-SOL50M	~90 EUR	12V, 50W max, cf. Amazon
car battery	Profi-Start 36Ah	~23 EUR	12V, 36Ah (bought at tip Auto in Berlin)
charge controller	Conrad	~34 EUR	max. 6A, protects against deep discharge of car battery, Conrad; this cheaper one should also work.
small parts		~20 EUR	cable 1,5mm². + and - car battery connectors. car fuse socket and 10A fuse (attached directly at + connector of car battery). cable lugs. DC cable and connector for router. optional: waterproof connector (for easy unplugging of the solar panel), for example a superseal connector.
optional: 3g/UMTS USB device	Huawei K3520 / E169	0 EUR	got mine from a friend, but you'll get them with any dataplan