Like most people I spend a tremendous and alarming amount of mental energy worrying about dying batteries. So many of our devices have fruit-fly batteries, incapable of lasting an entire day.  Batteries will fade two ways simultaneously — getting weaker by the minute in real time even as, viewed broadly, they are aging, and become less capable of holding a charge. To be sure, the smart, young, hip digital people have special electronic devices running on plutonium decay, or whatever, so they don’t have to worry about these things. But I’m just a newspaper hack with a Dell laptop and an iPhone 4 and a little Verizon aircard-like doohickey and a digital camera, all of which conspire to grow weak simultaneously, threatening to expire in a kind of electronic version of the Permian/Triassic Mass Extinction.

Now throw in a new, confounding element: Airplane WiFi. A typical Go-Go InFlight WiFi access costs $10. That’s kind of a lot of money to pay to get online, but there are times when you have to do it, just because of the discomfort with being offline, out of touch, unreachable, incommunicado, disconnected and potentially obviated. It’s okay to be offline for a couple of hours, sure, you’re not likely to be replaced at work by a 23-year-old in the interim, but you don’t want to push it much beyond that.

Let’s say you are flying, as I did yesterday, from LAX to IAD, about 5 hours airborne. My Dell is good, lately, for about 90 minutes before the battery goes kerplunk. I have to conserve that juice as much as possible. The smart traveler carries printed publications (yesterday I had The Economist, The Los Angeles Times, USAToday, The New York Times, and two novels), because these things don’t require batteries. When you read the newspaper on an airplane you can feel virtuous, because your batteries are at rest. If a Digital Person gives you a funny look as you are reading something in print, you can just say, cheerily, “Giving the ol’ batteries a break!” And then usually you’ll be left alone.

But you have to handle your printed reading matter and your electronics very strategically. On a 5-hour flight, when do you go online? Let’s say you have roughly 1 hour of battery life left. You want to devote some percentage of that to writing, and some percentage to checking email, and then some very small percentage of it to scanning the news headlines. It would make no sense to check your email very early in the flight, because you already checked it on your smart phone in the security line and then while sitting on the plane before they closed the door and told you to turn off your phone and then scolded you for being slow about it.

In crafting your electronic strategy, you have to think a step ahead. Your goal has to be interaction termination. That’s when you find a way to make an email exchange come to a satisfactory conclusion for everyone involved. Otherwise people will keep lobbing emails at you and won’t grasp that you’re only online by your fingernails up here at 37,000 feet and have a dying battery. The best strategy is to get online about 90 minutes into the flight and then again about 90 minutes before landing. You should also stick to Monitor Mode, as opposed to Interaction Mode. You just need to make sure there are no fires out there, no disasters.

This can also be good training for regular, non-aeronautical life. You have to train people to understand that you often can’t be reached and are very unlikely to be responsive in the short run to any query or request. If you are quick to reply, people will think you’re always online, and then you run into that situation in which people say, “Didn’t you get my email?” and it turns out they sent it exactly 2 minutes earlier. “Actually, no, I didn’t check my email in the last 120 seconds,” you could say, snarkily, but really this situation is your own fault. You didn’t train the person properly. You made the mistake of creating the impression that you were digitally available.

In sum, modern life requires that you figure out strategies for being there but not entirely there, or being there but not obviously there. Lurking is not just a strategy, it’s a skill. And maybe you should get some extra batteries.