The maximum discharge current provided by the battery is the maximum current that the battery can deliver without the risk of overloading, overheating and other troubles. This indicator directly determines compatibility with a specific device: the current consumed by the load must not exceed the maximum battery discharge current.
The maximum discharge current is indicated only for rechargeable batteries (see "Type"). By definition, it is greater than the nominal one (see above), but it is worth recalling that when the rated current is exceeded, the voltage at the battery output decreases. Therefore, in some cases, it is necessary to choose a battery exactly according to the rated discharge current.
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
...for which the battery is purchased has its own protection circuits, the optimal choice for such a load would be a regular, “unprotected” power source.
