Charge! Everything you need to know about batteries and charging

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10 tips to keep your mobile devices charged and happy

The batteries that your mobile devices contain are miracles of engineering. They hold amounts of energy that their predecessors couldn’t come close to equaling. Properly using this potential can help your mobile batteries last longer on the road. Here are our tips for obtaining optimum battery performance.

1. For the quickest Tablet charge, use the original charger or a charger specifically designed for it.

When charging tablets, use the charger they came with for best results.

iPads and other tablets have large batteries, so they come with chargers that can output lots of juice to recharge them quickly. For example, the iPad's adapter can output up to 2100mA (2.1 Amps), which is more than double the amperage that a typical USB port can support. This extra power output makes a huge difference. In our tests, charging an iPad took 5 hours, 9 minutes with the iPad charger (which can deliver up to 2100mA), but it took 10 hours, 13 minutes with an iPhone 5 charger (which maxes out at 1000mA). In a similar test with a generic USB travel charger, the charger took more than 24 hours to build up a full charge in the same iPad.

As these tests demonstrate, to reduce charging time to a minimum, you need to use either the original charger or one designed specifically for your device. Some devices contain circuitry that won’t allow the battery to use the charger's full capacity unless the charger contains a special authorization chip: otherwise, the device will charge at a much slower rate. For instance, when we tried to charge an iPad 4 with a Samsung Tab 10.1's charger, the process took over 19 hours to complete, even though the Samsung charger can deliver the same amount of juice as the original iPad 4 charger. That’s because the iPad 4, not recognizing that the charger could deliver a larger flow of power, limited the incoming current to an unnecessarily low level. The same was true of the reverse situation: When we tried to charge a Samsung Tab 10.1 tablet with an iPad 4 charger, the process took more than 15.5 hours. In contrast, the original Samsung charger completed its work on the Tab 10.1 in 4 hours, 46 minutes.

2. Most cell phones don’t need a specific charger.

Cell phones, which carry smaller batteries than tablets use, don’t require high-current chargers. As a result, you can use a generic charger to transfer power to them, without suffering a severe slowdown in charging time. When we timed how long an iPhone 5 took to reach a full charge when fed by various chargers, the differences ranged from 2 hours, 4 minutes with an HTC travel charger to 2 hours, 59 minutes with a Samsung charger. The original iPhone 5 charger took 2 hours, 16 minutes—so you won’t suffer much of a penalty for using a third-party charger with your cell phone or other small device.

3. Use a charging USB port or a powered USB hub.

If you don’t have a charger handy, you can recharge via a USB port. USB 2.0 ports come in two types: standard and charging. The difference is in the amount of juice they can deliver: A standard USB port delivers a paltry 100mA, whereas a charging port can deliver a much more respectable 500mA. That’s why, when you plug a power-hungry device into some ports, it either won’t charge at all or will charge very slowly. Though many laptops offer a combination of standard and charging USB ports, many manufacturers do a poor job of identifying which ports are of which type; in such cases, the only way to find out is to try each port in turn. Even more confusingly, some ports on fairly recent laptops can provide up to 1.1 Amps of current when a device that can use it is plugged in. Check with your system's manufacturer to see what types of ports it has and what amperage they can deliver to your device, before relying on them to keep your devices charged and ready to go.

Although USB 3.0 ports can deliver more juice (up to 900mA) than USB 2.0 ports can, they perform at this level only with USB 3.0 devices. If you plug a USB 2.0 device into a USB 3.0 port, the port will deliver the same maximum 500mA that a USB 2.0 port would.

If you use an unpowered USB hub, the available current will be divided across all of the ports, which won’t leave enough to charge your devices. A powered USB hub can deliver the full amount of charging juice to each and every port, which makes it a better option for charging your devices.

You can use any micro-USB cable, not just the one your phone came with.

4. You can use any Micro-USB cable to charge your phone if the phone has a Micro-USB port.

For devices that have Micro-USB ports, you can use any cable that has a Micro-USB plug on the end for charging; you don’t need a special cable.

5. The first time you charge a device, let the device charge completely, and then discharge it until it runs out of juice.

The first charge cycle of any device is important: It conditions the battery and helps the device figure out how the battery behaves. So, when you first plug it in, leave the device on to charge for at least 12 hours, then unplug and run the device until the battery is empty.

For comprehensive coverage of the Android ecosystem, visit Greenbot.com.

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