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.
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.
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.
6. You can safely leave devices charging.
Modern mobile device batteries contain circuits that control the flow of power, so it is safe to leave them plugged in and charging for long periods. When the battery is fully charged, the battery management controller will regulate the flow of power to keep the battery topped up, but won’t overcharge it. Which is a good thing, as an overcharged Li-Ion battery could explode.
7. It is good for your batteries to occasionally completely run them down and fully recharge them.
Modern Lithium Ion batteries don't suffer from the memory effect problem that plagued their older nickel-cadmium cousins, so you can safely recharge your device even if the battery hasn't completely run down. Nevertheless, manufacturers recommend running the battery down and recharging it fully at least one a month to maximize the battery's life, as this helps keep the battery conditioned and helps preserve its chemistry.
8. Treat your batteries with respect.
If you treat them well, your devices' batteries will repay you with years of service. But if you don’t treat them well, they won’t respond well—which is a problem because the insides of batteries are dangerous places. It may help to think of batteries as small chemical fires waiting to happen: You should always carry them in the device or in a case (if you're carrying a spare). Never poke, puncture, or otherwise mistreat them.
9. Replace (and recycle) your batteries every two years or so.
As batteries get older, their ability to retain a charge diminishes, and consequently your device's battery life gets shorter. This gradual but inevitable process reflects chemical changes inside the battery. Most batteries should be good for a couple of years, though: Apple asserts that the battery in an iPad will hold 80 percent of its maximum charge after 1000 charges, and other manufacturers make similar claims.
When you do replace them, recycle the old batteries at a hardware store or other designated rechargeable battery drop-off. The Call2Recycle website will help you find a recycling station in your area. Don't discard any recyclable battery into the trash, as its ingredients are quite poisonous and potentially combustible.
10. You can diagnose a USB power problem in a few simple steps.
If you're trying to use a USB port to charge a device, but it isn't working, you can find tools in Windows that may improve the situation. Unfortunately those tools are buried rather deep in the system. To get to them, go to Control Panel > Device Manager, and select Devices by Connection from the View menu. Click the top item on the list (which should be the name of your PC), and press the * key. This will open a list of all the devices connected to your system. Scroll down until you find one called 'Generic USB Hub'. This is your computer's built-in USB hub, which connects the USB ports in the case. You may have more than one such hub, depending on your system. Right-click Generic USB Hub and select Properties. In the Generic USB Hub Properties window click the Power tab, and you'll see a list of connected USB devices, together with the amount of power that each one is drawing. This information can help you determine whether the device will charge quickly (if the number is, say, 500mAH or above) or relatively slowly (if the number is less than 500mAh). When I checked this list on my computer, I found that my cell phone was drawing just 96mA. As a result, even though the phone reported that it was charging, it was receiving only a trickle of power, and would probably never have charged fully.