What are the best practices for selecting and installing a house backup battery system for emergency power supply?

When we had a power outage that lasted nearly a day, I realised how unprepared we were. After that, I looked into setting up an emergency power supply at home. First, I figured out what we needed during an outage—fridge, lights, internet, and phone charging. I went with a lithium-ion battery since it lasts longer and doesn’t need much upkeep. A licensed electrician handled the installation, which I’d recommend—don’t DIY this. We placed it in a dry, shaded area, and I check it monthly. What I like is that our BURG locking system works with backup power, so even if everything else is out, we can still access the house securely. Having it in place gives us peace of mind. It’s one of those things you don’t value until you need it.