With the heatwave that is hitting the country this month, electrical grids are pushed to the maximum. As such, brown outs are common. But when you have no electricity at all, how can you guarantee that your smart phone or tablet’s battery will go the distance? Here’s a few tips on how to squeeze every last minute out of your gadget’s battery.

1. Get a backup

Having a backup battery is often a great way to extend the life of your gadget. For some, like owners of the HTC Thunderbolt or Sprint Echo, having an extended battery is a way of life just to get through the day. But backups, whether a dedicated battery that you install, or one that is built into a protective case, like the Mophie Juice Pack Air (http://www.gadgetreview.com/2010/11/mophie-juice-pack-air-review-for-the-iphone-4.html) can be a godsend when you need extra time before hitting the plugs to recharge.

2. Engage your autolock feature

This has a two-fold benefit. First, it will put your phone’s display to sleep after a set time (mine’s a minute), and two, it can also be set with a password so that if someone steals your phone or you lose it, after ten tries, the phone erases all data.

3. Adjust your display settings

I like a bright screen and as such, I usually turn off the auto-brightness feature of my iPhone and adjust it myself. That way, I can determine how much I need at any given time. It also allowed me to turn it way down to save battery power during my recent power outage. Having the auto-brightness setting enabled can also help in that it uses the proximity sensor to determine the most efficient screen brightness during the day. Additionally, after using it, click the lock button to put it to sleep manually. This will save a we bit as the phone isn’t waiting for the autolock to engage.

4. Turn on WiFi and 3G/4G Data

If you’re going to be out all day, you really don’t need the phone’s WiFi radio searching for a signal. Doing so bleeds out battery power. So why not turn it off until you really need it? And turning off 3G/4G data in favor of a slower EDGE just to get you through the time won’t hurt either.

5. Avoid extreme temperatures with your phone

Extreme cold or heat will drain your battery faster than a vampire during Spring Break in Miami. The ideal temperature of your gadget is 72℉, 22℃. So keep it out of direct sunlight in the summer, and in your pocket during the winter.

6. Turn off your push feature

Rather than have data pushed to your phone all day, set the phone to search for emails, status updates, and text messages at intervals. This will save power – and data cap space – as your phone isn’t always searching for data that isn’t there.

7. Turn off Bluetooth

If you aren’t driving around and looking silly with a stubby headset sticking out of your hear, make sure your bluetooth capability is disabled.
8. Put the display to sleep while on a call. If you’re using your earbuds to talk, the phone will stay on until the autolock engages. So why not just put it to sleep manually? Also, limit any additional multitasking while on the phone. If you’re talking the old fashioned way, the phone’s proximity sensor will dim the screen while you’ve got it against your ear. So you’re good to go there.

9. Turn off additional apps completely

Most apps get left on when you leave them, and deactivating them completely will prevent them from using CPU power while inactive. This also gives you the benefit of having a faster phone when you need it.

10. Use your laptop to charge it

When our power was out last night and the battery started to die, I remembered that my laptop battery was completely fresh. So I hooked up my phone and topped it off using the laptop’s power through USB. And it only used up about 25% topping off both my phone and the backup battery (of which I have two).

11. Finally, limit the playtime

In situations where you don’t know when you’ll be able to recharge your battery, it’s probably best to prioritize your use of your gadget for the most important things like making phone calls, etc. Watching YouTube Videos or playing Angry Birds nonstop will leave you in the dark after only a few hours. So remember what’s important. You can do without playtime for a day to make sure people can keep in touch.

James DeRuvo