Ideally, you’d always have your charger handy. But your workday doesn’t always go according to plan. So if your charger’s at the office and you’re not, how can you keep your power going as long as possible? Here are our top five tips:

Be kind to your battery. Keep the contacts on the battery clean. Don’t let your device get hotter than about 95 degrees Fahrenheit. You might even reassure it (and yourself) by carrying a spare.

Economize. Wi-Fi is a heavy power consumer—on all devices. Keep the screen as dim as you can stand it. Keep an eye on apps that run in the background, or just disable them. Extend the refresh time: Set your email to pull new messages every 15 minutes (or even longer) rather than as soon as they arrive on the server. And whenever possible, put that baby to sleep.

Do some digging. Look for apps like iOptimizer or Battery Graph to help you monitor your use.

Don’t turn it off. Really—your tablet or phone will use more juice powering back up than it will quietly napping.

Charge it! But not too often. If you can, wait till the battery’s down to about 10 percent, then fill ’er up to 100 percent, but without overcharging. Whatever you do, don’t charge a battery that’s already above 90 percent.