Sometimes it seems our family runs on batteries.
The alarms in the morning, the clock downstairs, a light, the phones, the calculators for school, the camera, another clock, etc etc.
You name it and the chance it runs on batteries is very high.
So we use a lot of batteries. In fact we have a special drawer full of batteries, so people can find full ones anytime. That's especially handy for my son the photographer. When he's run out of batteries he comes to us.
We don't often buy batteries. There's absolutely no need to spend a lot of money. We use rechargeable aa batteries, even in equipment that comes with a note that rechargeable shouldn't be used. We've never ever experienced problems. It should be noted though that we always use a battery until it's completely empty and we keep them in a very dry and clean environment.