The Mercury Inverter 1.2KVA Complete System 100ah.    Ideal for a one-bedroom flat, private office and small shops. Example use case:

1. Laptop
1. Modem/Router
1. Solar Fan
2 Energy Saving Bulbs
Smartphones

This system will keep the above items (total 150 watts) powered for approximately 4 to 5  hours or more depending on usage.