I have a couple of those lanterns. I go through the same thing here with batteries. I don't let my devices sit with batteries in them. But even keeping batteries around for use when needed can be bad. They just eventually corrode. I guess you can only be so much prepared and hope for the best.These are probably 5 or 6 years old and run on three AA batteries. You pull the top of the lantern up, and the LED lights inside turn on when you raise the top. They have a couple rectangular folding handles attached to the top.
My other half just discovered why one of them is not working. It's that pesky "why you're not supposed to store batteries in devices in Florida if you don't use them on a frequent, regular basis" reason. Corrosion.