Are you old enough to remember when disposable alkaline batteries were your only option for electronic devices? If so, you may have memories of buying D-cell batteries for your flashlight and a 9V for your transistor radio. Those were the days, right? Today, it seems like everything runs on batteries.

Everything from cell phones to laptop computers are battery-operated. In the kitchen, we have battery-powered mixers and electric knives. Out in the garage we have battery-powered lawnmowers, trimmers, and hedge clippers. You might even have an electric car.

Despite how far batteries have come over the last decade or so, there are some things we will probably never trust to battery power. Below are five of them, compliments of Pale Blue Earth, a Utah company that makes USB rechargeable batteries for consumer electronics.

1. Airplanes

We do not have a problem with battery-powered cars and trucks. If a car’s battery pack dies en route to grandma’s house, it instantly becomes a parked car. If a battery-powered boat runs out of juice, it floats on the water until help arrives. If a battery-powered airliner runs out of power, it falls from the sky.

Pale Blue Earth says that battery-powered airplanes would be challenging for another reason: batteries don’t do well under extreme conditions. Unless something in battery technology changes, the differences between surface temperatures and those at 30,000 feet make battery-powered planes too risky.

2. Military Vehicles

All sorts of military vehicles have to be ready to go at a moment’s notice. They also have to be reliable. That being said, it is hard to imagine tanks, Humvees, and helicopters ever being powered by batteries. As things currently stand, military vehicles can be refueled in the field extremely quickly. How do you quickly recharge a battery pack in the heat of battle? Even the fastest rapid chargers cannot recharge batteries as quickly as pumping a fuel tank full of diesel.

3. Hot Air Balloons

Hot air balloons get their lift from hot air produced by propane burners. The heat has to be intense enough to lift the balloon in the air before it cools. As things currently stand, producing that much heat with battery power would require battery cells so heavy that they would be impractical for balloon flight. On the other hand, propane and the tanks that hold it are comparatively light. Burning propane produces a lot of heat in a short amount of time.

4. Stoves and Ovens

Stoves and ovens require a fair amount of concentrated heat to do what they do. If you have ever examined your stove at home, you may know it’s on a dedicated circuit with a higher voltage than any of the others. That’s because it draws a lot of power. Operating a stove or oven on battery power would be impractical. By the way, the same goes for your clothes dryer. The chances of it ever being run on a battery are slim to none.

5. Computer Servers

The computer servers that run the internet are among the most power-hungry devices in the world. They consume a tremendous amount of energy to keep data moving around the world. What is not used for data transfer is used for cooling. It’s hard to imagine that we could ever produce batteries powerful enough to run servers reliably.

As fantastic as battery technology is these days, it does have its limits. There will always be those electrical devices that cannot be run on battery power. That means there will always be a need for the grid. That is just the way it is.