Comparison Samsung EP-TA845 vs InterStep RT 2USB 2A

The number of USB connectors in the design of the device. We emphasize that here we are talking only about classic, full-size connectors — the so-called USB A; the number of USB-C ports, if any, is specified separately (see below).

The number of USB ports (of any type) corresponds to the number of gadgets that can be simultaneously connected to the charger using adapter cables or plugs for the appropriate connector. Note that not all chargers are capable of delivering full power to all charging outputs at once; see "Charge current" for details. As for the specific number of ports (USB A and/or USB-C), nowadays, relatively simple chargers for 1 port or 2 ports are the most popular. This is due to the fact that separate chargers are usually purchased for one or two specific gadgets, and a larger number of charging outputs is required relatively rarely. However, on the market you can easily find models with 3 ports or 4 ports ; and the most “multi-charged” modern devices have 5 or 6 USB ports or even more.

The number of USB-C connectors provided in the design of the charger.

USB-C is a relatively new type of connector; it has dimensions slightly larger than microUSB and a double-sided design that allows you to insert the plug in either direction. At the same time, despite their compact size, rather advanced features can be implemented in such charging ports — in particular, high power supply and many fast charging technologies. On the other hand, specifically in chargers for gadgets, connectors of this type are much less common than full-sized USB (USB A), and in smaller quantities — one at a time, less often two. This is due to the fact that a cable is usually used to connect rechargeable gadgets, with detachable cables it is more convenient to use ordinary USB ports, and installing such ports in a charger (even a compact one) is easy. So in fact, it makes sense to specifically look for a device with USB-C mainly if the you have such a cable already (or a gadget with a suitable plug).

The maximum current that the device is capable of delivering to the charging output. This is one of the key parameters for any charger, it directly determines its power and, accordingly, its efficiency with certain batteries. These points are described in detail in the “Power” paragraph below, but here we note that if several values are indicated in this paragraph, it means that the design provides for several connectors with different current specs (or several groups of connectors, each with its own amount of amperes per port) .

As for specific numbers, when charging from USB (used in most modern chargers), the maximum current up to 1 A is considered very limited, 1.5 A is low, 2 A, 2.1 A and 2.4 A are average values, and in the most powerful chargers, this figure can be 3 A, 3.4 A and even 5 A.

The maximum power that the charger is capable of delivering to one rechargeable gadget (for models with 1 connector or with 1 wireless platform — the actual charging power). We emphasize that for wireless devices, it is the power in the wireless format that is indicated here (even if the design has a USB port with a higher power). Wired chargers usually list the USB power with the highest charging current or with support of the most powerful fast charging technology.

The smallest value of this metric nowadays is actually 5 W. Other popular options include 10W, 12W, 15W, and the most powerful models have 18W or more to charge laptops(up to 100W).

Higher output power allows you to speed up the charging process; and in the case of wireless devices, a value of more than 10 watts already allows us to talk about the presence of fast charging. At the same time, a number of nuances are associated with this parameter. Firstly, not only the charger, but also the gadget being charged should support the appropriate power — otherwise the speed of the process will be limited by the specs of the gadget. Secondly, in order to use the full capabilities of the charger, it may be necessary to support not only the appropriate charging power, but also a...certain fast charging technology (see "Fast charging"). Thirdly, in a charger with several charging connectors, the maximum power per device can only be achieved if the other ports are not used.

Fast charging technology supported by the device.

By itself, fast charging, as the name suggests, reduces the charging time compared to the standard procedure. For this, increased voltage and/or current power is used, as well as a special smart process control. But the possibilities and features of such charging may be different, depending on the specific technology used in the device. The same technology must be supported by the charger too — this is the only way to 100% guarantee correct operation. However some types of fast charging are mutually compatible — this point should be clarified separately, and compatibility is not always full.

Nowadays, the following technologies are most widely used: Quick Charge of different versions (3.0, 4.0, 5.0), Power Delivery (version 3.0 and 3.1), Pump Express, Samsung Adaptive Fast Charging, Huawei Fast Charge Protocol, Huawei SuperCharge Protocol, OPPO VOOC, OnePlus Dash Charge. Here is a brief description of each of them:

— Quick Charge (1.0, 2.0, 3.0, 4.0, 5.0). Technology created by Qualcomm and used in gadgets with Qua...lcomm CPUs. The later the version, the more perfect the technology: for example, Quick Charge 2.0 has 3 fixed voltage options, and version 3.0 has a smooth adjustment in the range from 3.6 to 20 V. Most often, gadgets with a newer version of Quick Charge are compatible with more old charging devices, but for full use, an exact match in versions is desirable.
Also note that certain versions of Quick Charge have become the basis for some other technologies. However, the mutual compatibility of chargers and gadgets with support for these technologies needs to be clarified separately.

— Pump Express. Own development of MediaTek, used in portable devices with CPUs of this brand. Also available in several versions, with improvements and additions as it develops.

— Power delivery. Native fast charging technology for the USB-C connector. Used by many brands, found mainly in chargers and gadgets equipped with this type of connector. Presented in several versions.

— Samsung Adaptive Fast Charging. Samsung's proprietary fast charging technology. It has been used without any changes since 2015, so it looks rather modest compared to newer standards. Nevertheless, it is able to provide good speed, especially in the first 50% of the charge.

— Huawei FastCharge Protocol. One of Huawei's proprietary technologies. Formally similar to Quick Charge 2.0, but used with both Qualcomm and other brands of mobile CPUs, so compatibility is not guaranteed. In general, it is considered obsolete, gradually being replaced by more advanced standards like the SuperCharge Protocol.

— Huawei SuperCharge Protocol. Another proprietary technology from Huawei introduced in 2016; for 2021 is available in several versions. In some devices, the power of such charging exceeds 60 V — not a record, but a very solid indicator.

— Oppo VOOC. OPPO technology, used both in branded smartphones and in products from other brands. Available in several versions; The latest (for 2021) version of SuperVOOC is for 2-cell batteries and is sometimes listed as a separate technology called Oppo SuperVOOC Flash Charge.

— OnePlus Dash Charge. A relatively old proprietary standard from OnePlus. An interesting feature is that in some gadgets, the effectiveness of Dash Charge is practically independent of the use of the screen: when the display is on, the battery charges at almost the same rate as when it is off. Technically a licensed version of OPPO's VOOC, however, these technologies are not compatible. Since 2018, Dash Charge has been phased out by Warp Charge, but this newer technology is rarely used in separately sold chargers.

In addition, on the market you can find chargers that support rarer and more specific formats of work; the features of these formats can be clarified by special sources.

— Operation indicator. In some models it also provides additional information about operating modes, malfunctions, etc. Most often, such a light indicator is in the form of a separate light or a clearly visible backlight system. And additional information can be provided by changing the colour of the backlight, by blinking, etc. However, even without these features, the operation indicator provides additional convenience in use. In particular, it allows you to determine whether the charger is receiving power and working normally — this can be useful when diagnosing various problems. It is also possible to use non-standard backlighting — for example, as a night light that makes it easier to navigate in an unlit room (especially since gadgets are often put on charge just at night).

— Display. Own display on the charger case. This is usually the simplest screen with a few characters, but it is enough to display various additional information that makes life easier for the user: current voltage and current values, fast charging status, error codes, etc. On the other hand, this complicates the design, but in fact such information is required less often; Therefore, very few chargers with displays are produced.

— Detachable charger power cable. Cable for connecting the charger to the power source, which has a removable design. By itself, connecting to a power outlet using a separate wire (both re...movable and non-removable) is rarely used in charger devices — mainly in devices for which the “plug on the case” type design is not suitable (this is primarily wireless models, as well as wired charger devices with an abundance of connectors and corresponding dimensions). Specifically, the removable design is convenient in two ways: firstly, the wire can be removed and compactly folded for storage and transportation, and secondly, if the cable is damaged, it can simply be replaced, no need to bother with repairs. The disadvantages include an increased probability of losing the cable, as well as a slightly lower reliability than with a non-removable design (the latter, however, becomes noticeable only with frequent connections/disconnections that wear out the connector).

— Non-detachable charger power cable. Cable for connecting the charger to the power source, rigidly fixed to the device and not intended to be disconnected. It occurs much less frequently than the removable one described above, since it is less convenient if necessary to compactly fold the device; and if the wire is damaged, most likely, you will have to carry the charger to a service centre. On the other hand, you can lose such a wire only together with the charger itself.

The presence of a cable in the delivery kit of the charger, or any other specific type of included cable.

The presence of a cable is indicated mainly for wireless devices (see “Type”) — in such cases, we are talking about the power cable of the charger itself. For wired models, the type of connectors on the stock wire (s) for charging gadgets is usually specified. At the same time, the USB port is used by default to connect to the charger itself, so this plug may not be mentioned in the description of the wire. On the other hand, there may be such connectors:

— USB-C. A miniature version of the USB connector, gradually replacing microUSB in modern portable devices. It has a convenient reversible plug design, and can also provide some advanced power options not available with microUSB. Also note that USB-C can be used in a cable not only to connect to a gadget, but also to connect to the charger itself (along with traditional USB); so on the market you can find corresponding cables like "USB-C — microUSB", "USB-C — Lightning", etc.

— microUSB. Universal connector, extremely popular in portable gadgets of various types; only relatively recently has it begun to give way to the more advanced USB-C (which differs from it in its one-sided design and lower power supply).

— Lightning. Universal connector, used e...xclusively in portable Apple devices. Like USB-C, it has a two-way layout, but a slightly different design.

The length of the cable supplied with or included with the charger. For wireless models, the length of the power cable of the charger itself is indicated here, for wired models, the length of the cord for charging gadgets

Anyway, a longer cable gives more freedom of movement, but it creates inconvenience for short distances. Also note that charging is supposed to be used in the immediate vicinity of sockets, so wires longer than 2 m are practically not found among such devices. A length of more than 1.5 m is considered significant, from 1 to 1.5 m — medium, from 0.5 to 1 m — small, and in some models there are wires shorter than 0.5 m.