Tested and owned homemade, built in, and removeable batteries for over 25 years. Way more than 25 lights. Built in is much less work, gives a little more performance, and usually longer run time.
I ride with a spare headlight, and a spare tailight. Plus small lights to fix a flat in the dark 50 miles from home. Li ion batteries run longer in the cold than other types of batteries.
For 15 or 20 years lots of 120 to 150 mile rides. Coming home at midnight or later often. My newest lights are all universal strap mounts, they rotate to 15 bikes. Some or the strap lights are over 10 years old, only one strap failure, it was 100f in the garage and I pulled too hard on the strap. One of my trikes is ridden with three tail lights, and three headlights. I have a power strip with lots of chargers on it. Need to charge my camera, my phone, and my lights all at once. It's easy. Almost forgot, a helmet light and a backup helmet light.