How a USB Battery Charger Can Charge Two Tablets at the Same Time
USB is one of the most popular ways to connect portable devices to a PC. Often overshadowed by its data bus counterpart, USB also contains a power-bus that can supply a maximum of 5.25V/500mA at full rate.
But charging batteries with USB can be challenging. It requires balancing battery “care and feeding” with the limitations of USB power, as well as the size and cost barriers present in portable consumer device designs.
Charges 2 Smartphones or Tablets
Bigger batteries (aka power banks) may have more than one USB port, which means you can charge two smartphones or tablets with the same battery. This is especially helpful when you need to get your phone up and running quickly, or even for charging a friend’s smartphone or tablet.
Most portable devices charge by using a USB cable connected to a wall charger or other type of charger. These cables can be bought from a variety of sources, including the hardware store and online. Some cables are compatible with USB 2.0 or 3.0 ports, while others use a special fast-charging technology called USB Power Delivery.
Regardless of the specifics, each USB connection has four pins: +5VDC, ground and D- and D+. These are used to negotiate current with the device’s controller chip, which defines the current in amps at which the battery charges.
This can vary by battery and by the type of charger you have. Some of these are designed to provide more current than others, but each will have its own limitations.
Another limitation is the battery’s tolerance for voltage and current. For example, a modern lithium-ion battery will only charge as fast as its controller chip allows it to do so. This can be a problem when using a high-wattage charger, as you might not be able to charge the battery fast enough.
Some modern USB chargers have a special chip that determines how much current to deliver to usb battery charger a battery, in order to charge it as quickly as possible without overloading the USB port or damaging the device’s circuits. The chips are also designed to protect the battery from overheating and overcharging, which can damage it over time and reduce its lifespan.
The battery charger’s chips and the quality of the cable can also influence how fast your portable device charges. Higher-quality cables will transport a greater amount of current, which will make it quicker to charge your phone or tablet.
This is because each USB charge port has a fixed output, so it will only draw the power it needs to supply its device, which can help it charge more quickly than a charger that has a variable power output. It can also be difficult to get the right power balance, as each port might need its own specific current to reach its maximum potential.
Charges 1 Smartphone or Tablet
USB is an acronym for Universal Serial Bus, a standard that has seen many iterations and innovations over the years. The most recent version is USB 3.0 and brings data rates to the table that were unheard of just a few years ago. It also introduces new technologies and features such as power delivery and charging.
The most powerful USB port on the market today is capable of 5V and a whopping 500mA, which is more than enough to charge an iPhone 7 without a problem. However, if you have more than one device attached to the same port, you might experience an overload that can cause system failures or even damage your devices.
To ensure your phone gets its power it must be able to communicate with the charger in a way that both parties are on the same page. A USB hub is the logical answer to this conundrum, but it can be expensive and inconvenient.
Finally, the most efficient way to get your devices charged is with a self-enumerating charge controller IC that selects the best possible charge mode for your device from among the plethora of options available on board. This is a clever little trick that doesn’t involve the CPU, which can be busy handling other tasks such as running your apps.
It is a shame that most people usb battery charger have no idea how much power they are actually receiving from their USB sockets, as well as the many other devices on board. The best thing to do is invest in a good quality, reliable USB hub that will keep your devices powered up for the long term.
Charges 1 Tablet
A usb battery charger will charge a tablet but it may be slow and not at the best possible speed. USB was not specifically designed for charging but the newest version, USB 3.0, incorporates power management capabilities into its core specification. This allows it to charge devices at the highest possible speed, even with the largest batteries. This includes an integrated charger that senses a battery impedance so it suspends charging when a faulty battery is plugged in, a feature that can come in handy in a pinch. It also features a dedicated charging port (DCP) which BC1.1 defines as the USB battery charging acessory of its ilk and the utmost of the illuminating of the USB world, namely a DCP that can supply 1.5A.
Charges 2 Tablets
If you have 2 tablets, this usb battery charger can charge them both at the same time. It supports USB Battery Charging Specification 1.2, which guarantees compatibility with a wide range of tablets and phones. The standard USB plug has four pins, with the shorter ones carrying data and the longer ones delivering 5V. The spec also allows a high-power port to deliver 900mA (USB 3.0) or 150mA (USB 2.0). It can sense the impedance of a battery to determine whether it’s an alkaline cell or a faulty one, suspending charging if that happens. This feature is especially useful if you’re in an emergency and don’t want to worry about plugging in an alkaline battery, which may cause damage to your device.
You can also use a usb battery charger to power an Apple Watch. It can deliver 34 watts of power, which is enough to charge your watch and a tablet at the same time.