Rated discharge current
Rated discharge current provided by the battery. This is the highest discharge current at which the battery will operate without a voltage drop and without a noticeable decrease in the actual capacity. It is worth paying attention to this parameter first of all if the battery is purchased for a device that is sensitive to supply voltage — for example, for a multimeter.
The rated discharge current is indicated only for rechargeable batteries (see "Type").
Charge cycles
The number of charge cycles that the battery can withstand without noticeable deterioration in performance.
The charge cycle refers to the period of time from one complete discharge of the battery to another, when the battery is first fully charged and then discharged to zero. In practice, this method of operation is relatively rare - much more often the batteries are charged under-discharged, and sometimes the process has to be stopped before the charge is replenished to 100%. In addition, the number of charge cycles is usually indicated for ideal operating conditions: a “native” charger, a relatively low load during operation, compliance of the ambient temperature with operating parameters, etc. Therefore, the number of cycles indicated in the specifications is quite approximate, and in practice it is unlikely that you should expect a 100% exact match. Nevertheless, by this parameter it is quite possible to evaluate the durability of the battery and compare it with analogues.
Protection board
Built-in electronic circuit that protects the battery from operating conditions.
This function is found mainly in lithium-ion batteries (see “Technology”). This is due to the fact that such batteries have fairly strict charging and discharging rules; violation of these rules (primarily overcharging and overdischarging, as well as overcurrent) can lead not only to battery failure, but also to fire and even explosion. To avoid such troubles,
protection boards are used: they primarily control the charge level, as well as charging and discharging power.
This feature is highly recommended if the battery is to be used in a device that does not have its own battery controller. A striking example is electronic cigarettes with mechanical battery mods, in which the atomizer coil is connected to the battery virtually directly. Without a protection board, the customer must carefully control the operating mode himself - and this is not so easy, given the absence of any additional indicators in the same “mechanical mode”.
On the other hand, it is worth considering that this function affects not only the cost, but often also the dimensions of the battery - it can increase its length by several millimeters beyond the nominal size. For example, 18650 elements with a protection board are not 65 mm long, but about 68 mm. In some cases, this can create problems with installation, or even make it impossible. So if the device fo
...r which the battery is purchased has its own protection circuits, the optimal choice for such a load would be a regular, “unprotected” power source.USB charging
The ability to connect the battery directly to the USB port for charging. The specific implementation of this function may be different. Most often, a miniature socket like microUSB is provided on the battery case, and a corresponding cable is included in the kit, however, there are also more original solutions — for example, a built-in USB connector, covered by a lid during normal use. Most elements with this function belong to the popular 18650 size, but it can also be used in other sizes — in particular, AA and PP3.
