Is there hard wired battery backups for lights?

My grandmother introduced us to 6-volt lantern batteries. The only problem is I stopped buying them because our local Walmart sold me one or more that didn't have power. My plan was based on what I have available. I save the 9-volt batteries from smoke detectors, and they still have power in them. I bought 9-volt flashlight toppers for them, but the price went up so I'm not optimistic. I started buying rechargeable flashlights and you want to buy the ones that you can replace the battery in. I also bought flashlights that take one AAA battery because a power outage that would use more than one AAA battery is not efficient in my opinion. I still think you want a flashlight with moonlight mode where you can put the flashlight down and be able to find it without losing all of the battery power in the flashlight. You might do well visiting the flashlight forums on Reddit as there are people with some nice collections that can tell you more about their flashlights. You may want a flashlight with a throw which means one that is powerful enough to light up your whole back yard if needed. There are USB lighters on AliExpress. If you have a power source, you can always use a lighter. Ham radio stores sell battery boxes with different connections for USB, USBC, power pole, 12-volt socket with 15-amp fuse. I like the Powerwerx Megabox 2 Portable at Gigaparts among others that aren't bad. I was looking into getting a solar cell but after asking someone knowledgeable about it, it is more complicated in the implantation for me to handle. Some converters that are cheap don't have a pure sine wave current for charging batteries and there are other issues. The other issue is chargers for rechargeable batteries. Some chargers are wired to A/C, and some are wired to USB where you can possibly charge them from a car or other devices. I may look into Leds that can be directly plugged into power banks because it would be less efficient to charge batteries with a power bank. Solar lights for your walkway and garden are sold at local stores. Just make sure you get a bright one with a good battery and try to find extra stakes for them online because they get lost easily. If you lose power, just bring them inside and charge them outside in the day. Keep in mind that if there is a real emergency, your neighbors may beg you for flashlights so you might want to head to the dollar store or buy some real cheap flashlights. I was also looking at 100% wool blankets if a problem would happen in winter where there is no electricity. I was looking at alleged military surplus sold on Amazon but they were not 100% wool so I'm looking for one that is 100% wool because I believe it would trap heat better.