Independent charge channels
The number of independent charging channels provided in the design of the charger.
If the voltage, charging current and other parameters in this model are regulated on all battery slots at the same time, this means that the device has only one channel. The presence of several charging channels allows you to set your own operating parameters on separate slots and, accordingly, simultaneously charge different types of batteries in one device. In this case, the channel can cover both one slot and several: for example, many models for 4 batteries have only 2 channels (one for every 2 slots).
The abundance of channels expands the capabilities of the "charger" and will be especially useful in cases where you often have to charge different types of batteries; on the other hand, it significantly affects the cost of the device.
Max. charge current
The highest current that the device can provide when charging the battery (or the nominal value of the charging current, if it is not adjustable).
Charging current is one of the most important parameters for any charger: it determines the speed of the process and compatibility with certain batteries. In general, the higher the current, the faster the process, the less time it takes to charge. At the same time, some batteries may have recommendations for the optimal current strength and restrictions on its maximum values. Therefore, mindlessly chasing a powerful charger is not worth it: at first it's ok to clarify how justified such power will be.
Note that in multi-channel devices (see "Independent channels"), the maximum current strength can be achieved when only part of the channels are operating. The indicators provided when all channels are operating simultaneously are indicated separately for such models (see "Charge current (all channels)").
Charge current (all channels)
The highest current provided by a multi-channel charger (see "Independent channels") at full load, with all slots (and, accordingly, channels) operating. In fact, a guaranteed maximum current provided by a multi-channel charger, regardless of the number of channels involved.
For the total charge current, see “Maximum charge current. Here we note that the full load is a rather complex mode in which the current strength can decrease. Therefore, this parameter is specified separately.
Overheat protection
A function that prevents critical heating of the batteries installed in the charger. Excessive heat on its own is usually a sign of a problem or abnormal operation, and an increase in temperature can cause a fire or even an explosion of the battery.
Overheating protection systems usually use special sensors that monitor the state of the battery and turn off the heating if necessary.