Что такое "количество циклов заряда/разряда"

это - количество циклов заряда/разряда

по-простому- это количество зарядов-разрядов аккума.
ещё проще- срок его службы

сколько раз ты полностью зарядил и разрядил аккумулятор.

В циклах указанна его жизнь в заданных приделах ёмкости - дальше тоже можно пользоваться но ёмкость акума будет уменьшаться и он сдохнет.

A discharge/charge cycle is commonly understood as the full discharge of a charged battery with subsequent recharge, but this is not always the case. Batteries are seldom fully discharged, and manufacturers often use the 80 percent depth-of-discharge (DoD) formula to rate a battery. This means that only 80 percent of the available energy is delivered and 20 percent remains in reserve. Cycling a battery at less than full discharge increases service life, and manufacturers argue that this is closer to a field representation than a full cycle because batteries are commonly recharged with some spare capacity left.

There is no standard definition as to what constitutes a discharge cycle. Some cycle counters add a full count when a battery is charged. A smart battery may require a 15 percent discharge after charge to qualify for a discharge cycle; anything less is not counted as a cycle. A battery in a satellite has a typical DoD of 30–40 percent before the batteries are recharged during the satellite day. A new EV battery may only charge to 80 percent and discharge to 30 percent. This bandwidth gradually widens as the battery fades to provide identical driving distances. Avoiding full charges and discharges reduces battery stress.

Зарядил с 0 до 100 мукумулятор, поставил в устройство, разрядил его до 0.
Это один цикл заряда-разряда.

Зарядил разряженный аккумулятор-один цикл.