Also get a power bank. I got this one a while back. Keep in mind that the higher the capacity, the heavier and bigger it will be. The one I linked is too heavy to comfortably be carried in pants pocket, but I can use it every day of the week without needing to recharge it.
Seems like most of their products are on sale though so make sure to give the other ones a look but this seems like the steepest discount of them all.
I've used their chargers and they are pretty big but have huge capacity and work pretty well. I currently use a Samsung fast charger but this seems like a good option for most who plan to carry a backpack.
The overhead light I mean the light on the ceiling of your car that turns on when you open the door. I turned it on to look for something in my car while it was parked. Since it turns on when the door is open I forgot to turn it off when getting out of my car. And my window tint made it hard to notice it was on when I got out. Did it like 3-4 times in a couple months.
Ultimately I'd like some type of high charge portable battery that has a power outlet so I could plug in battery chargers and radios and all.
The website says it has a 20Ah reserve. So something like this would probably be better, but having the availability to use a jump start, air compressor, and various outlets is nice for what I bought.
edit: This thing is pretty dumb.
Ankers pack is pretty cool.
Something like this is more useful to me since I ride a motorcycle.