Extra batteries come in all shapes and sizes – from Onaji Pawa’s credit card battery that can give you some extra time to use on the bus home to EC Technology’s monster 22,400 milliamp hour (mAh) battery that can charge pretty much any tablet or smartphone – more than once.
To think of
There are several things you should consider when choosing an extra battery. As small and light as possible with as high a capacity as possible is of course optimal, but often there is a trade-off between capacity and size. Another factor is capacity. Keep in mind that all the stored power will not benefit your mobile or tablet as some is lost in the form of heat. If the manufacturer does not specify a value, you can expect to get about 70 percent of the listed capacity. A battery of 10,000 mAh can thus give one of the newest tablets (with a battery capacity of over 7,000 mAh) almost a full charge. The capacity of new smartphone models such as Samsung’s Galaxy S, Google Nexus or Iphone 6 Plus is around 3,000 mAh, so the very cheapest and smallest extra batteries are not enough for a full charge (but are enough for a few extra hours of use).
However, don’t count on bringing a USB cable or charger – you can use the one that came with the mobile phone or tablet. Also keep in mind that it doesn’t matter if the battery supports charging with two amps if you plug it into a small charger with a maximum of one amp.
An extra battery with two amps in the usb connector cannot charge an older smartphone faster than the standard charger, because the vast majority of smartphone chargers charge with one amp.
If the battery has several contacts, you should also look at how high a total load it can handle. Four contacts with two amps each but a maximum of four amps in total means, for example, that it is slower to charge four devices than two.
You don’t have to worry about getting too much power in your smartphone by connecting it to a battery that can handle two amps – the charger sits in the phone and only draws as much power as it can handle.
Some batteries can be charged through, that is, you can use the extra battery at the same time as you charge your tablet or smartphone. Some also have automatic on and off so you don’t have to activate the battery when you plug in something to charge. Most have a small row of LEDs that show how much power is left in the battery, which works well with smaller batteries.
With really high capacity, however, it becomes quite pointless when each diode means such a big jump in charge. Some models have a small LCD screen instead that shows the remaining charge more accurately. l
Facts: Milliamp-hours (mAh), the most common measure of battery capacity. Stands for how long the battery can deliver power. 1,000 mAh = one amp hour.
Here are the three best in the test
Fast, durable and full of functions
We have tested 17 different batteries and all of them have a disadvantage of some kind. If they have a high capacity, they are heavy and unwieldy. If they are portable, they have
instead of low capacity to fully charge your gadgets. Or they have something else that prevents a top rating.
The exception is the Zendure A2. With a capacity of 6000 mAh, it is enough to charge a smartphone several times and to keep a tablet alive for a decent amount of time. It only has one plug for charging, but with 2.1 amps it is enough for all gadgets. The own charging takes place with 1.5 amps, which makes it reasonably fast, especially since it does not have quite as high a capacity as, for example, EC Tech’s two large models.
It’s also made of sturdy materials that can withstand being dropped on the hill, and has many of the practical extras that other, cheaper batteries lack: auto-on/off, charge-through, and the battery is also unusually good at maintaining a charge when it’s not is used. According to Zendure, it should retain 95 percent charge after six months.
EC Technology 22400mah
Maximum power that can handle most things
The highest capacity of the test with 22,400 mAh. This means that you can charge a smartphone around ten times or a tablet twice. It has three connectors with 1, 2 and 2.4 amps and you can charge almost anything at full speed. It charges at two amps, which is nice as it goes much faster. It still takes 14-15 hours from empty to full, but with the most common one amp it takes almost 30 hours.
Not as pretty as some of the rivals but has a certain charm. Available in black with red edges and in white, blue and white, as well as red and orange. One sad detail is that it only has four diodes to show the remaining charge.
Intocircuit Power Castle
Smart display shows the charge
A complaint about most cheap spare batteries is that they only have four small LEDs that show the remaining charge. The Power Castle is a nice exception with a clear LCD screen that more or less accurately shows how much soup you have left. It can fully charge a tablet once or a smartphone five times. You can charge with 1.0 or 2.1 amps. As in several other cheaper devices, it can only be charged with one amp. It fits well in the hand and has a good shape, but weighs a little more than other batteries of similar capacity.
Facts and ratings on all tested charging stations.
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