— powered by replaceable elements (batteries or accumulators) of standard sizes: AA, AAA, CR123, etc. The main advantage of this option is the ability to quickly replace dead batteries with fresh ones - the replacement process takes a couple of minutes at most, while for a built-in battery the only way is often charging, which takes quite a long time. Batteries are sold almost everywhere. On the other hand, with this type of power supply, you will either have to regularly spend money on disposable elements, or separately purchase batteries and a charger for them - additional costs cannot be avoided. Another important nuance is the dependence of the autonomy of the flash on the quality of the batteries: when using cheap elements that are not designed for serious "loads", the number of pulses per charge may be significantly lower than stated in the specifications. Nevertheless, these shortcomings are generally not critical, and this type of power supply has become quite widespread.
