For want of a nail the shoe was lost. For want of a shoe the horse was lost. For want of a horse the rider was lost. For want of a rider the message was lost. For want of a message the battle was lost. For want of a battle the kingdom was lost. And all for the want of a horseshoe nail.
It's usually not the big things that ruin carefully laid plans. More often than not, it's some small oversight that causes everything to come apart. Batteries can fit in that category. Everybody has them at home, if only for flashlights. Other than the once a year smoke detector battery swap out though, they just aren't an item that stays way up on your list of priorities.
There used to be a saying in the military, and for all I know it's still bandied about to this effect.
"You don't often need automatic weapons fire, but when you do, you really need it."
I would class dry cell batteries in the same way. Every single radio I have, be it an expensive shortwave receiver or a ten dollar hand held am/fm receiver, has to have a power source. Usually I operate them on AC adapters using grid power. If I lost the grid power, I'd use generator power. If that goes, the batteries are my final source. In the event of an emergency, one of the most pressing needs people have is for information. Even if what you are listening to is a government broadcast of doubtful veracity, you need that sense of connection. Working in an information void preys on a person's psychological well being.
There's also the very practical aspect of needing to know what's going on so you can make your decisions based on current facts. Did you ever watch the series "Jericho" on television? If so you will recall the herculean efforts they made to find out what was going on. The only shortwave set in the town belonged to an eccentric who let people use it for cash "I've got to have my fifty cents!" Radios won't work without batteries if you have no power.
I have a spreadsheet that shows every device in my house which requires batteries, and how many of that type of battery I have in storage at any given moment. The truth is I have a spreadsheet on almost everything, perhaps to excess, but at least I know what I've got. I keep them up to speed without fail. This lets me renew my minimum storage level on everything from batteries to aspirin. What your minimum level is depends on your own thoughts concerning how long you might be on your own.
Duracell and Energizer both say their batteries will retain their usefulness after ten years of storage. I use batteries a good bit and usually rotate through my supply long before that, so I don't know how valid that claim is.
I don't have any "rechargeable" batteries because I tried going that route with a little roll out solar panel that was supposed to recharge them. It didn't work. If anyone has successfully implemented that I'd appreciate hearing about it so I could buy myself the same rig they used. That would be a nice addition to my power source capabilities.
I suppose the most important thing you can do with batteries is replace them as you use them. If you don't, the time will certainly come when you need them, there are none to be had at the store (they are like milk and bread in an emergency), and you'll be SOL. (Surely out of luck.)