Preparing for a power cut & keeping phones charged

Redundant 5v System

A standalone system for charging all your 5v USB devices (phones/tablets/Bluetooth) rather than plugging into the mains every night. For example, a few power banks (10Ah) and a portable 13W/20W (to be effective in cloudy conditions) folding solar panel could keep all your 5v kit charged indefinitely, and give the flexibility of portable power for camping or that power cut. The other benefit is that power banks can also be charged at home or car.  The main key with portable power is ‘recover the charge you have used’, i.e. use power banks at night, and top back up at the first opportunity, it is not necessary to empty them.

Tablet versus Laptop

If it is not work-related (power/software etc) generally a modern Tablet can replace a Laptop. There are significant differences in how they use power. A laptop will generally need 12-19v for a 15Ah + (150Wh+) battery to last for around 3 hours, a Tablet needs only 5v for a 5Ah + (25Wh +) battery for 8 + hours and can recharge via USB power banks & small solar.  If you have cloud synching (Dropbox/iCloud/Google drive etc) you can switch between the more efficient Tablet and the Laptop as you need depending on available power or power cut. The other negative for the Laptop is that you will need an inverter to get 240AC to enable charging. An inverter will take power from a 12v power bank up to 240v to go back to the 12v your Laptop requires, a significant waste of power in the process.

 It is possible to keep this type of electrical kit going off-grid (Laptops/12-24V devices), but it is a big leap in initial outlay & bulk. For effective Laptop power away from the mains, you would really need a 300Wh + Power Bank & 60W + around 4 times the cost of running a Tablet off-grid.