What happens to a home battery during a power cut?
Not every home battery supplies power during an outage. Back-up functionality requires a suitable system and an adapted installation.
Many battery systems shut down during a grid fault. This is a safety requirement: no voltage may be fed onto the grid while work is being carried out on it.
Back-up, or emergency power, is therefore not an automatic feature of a home battery. It requires a system that supports it, a separate back-up circuit and correct isolation from the grid.
What's realistic
Often a limited back-up circuit is chosen, for example for lighting, internet and the fridge, rather than the whole house. What's possible in your situation depends on the system, power and installation.
Further reading
Advice for your own situation
General explanations help, but your home or building is specific. We're happy to work through your situation in concrete terms.