Battery Cycle, what is 1 cycle?

[mac26s]

What is 1 cycle?
What does 2000 cycles mean?
Is a cycle the battery's AH rating?

 

[sunshine_eggo]

What is 1 cycle?
What does 2000 cycles mean?
Is a cycle the battery's AH rating?

Cycle = charge + discharge or discharge + charge

The cycle depth is typically part of the specification.

Example cycle life.

2000 cycles to 80% depth of discharge.

This means that a 100Ah battery could be charged to 100% and discharged to 20% 2,000 times before the battery degrades to 80% of its rated capacity, i.e., 80Ah. There is also typically a temperature (25°C) and current as part of that specification, e.g., 50A charge and 100A discharge. The cycle life might also be dependent on a "preferred" charge/discharge rate of maybe 20A.

 

[uksa007]

EVE define it as:

6000 cycles:
Under the 300kgf clamp, after standard charged(3.65V 0.5C) and 30mins rest, discharge to 2.5V cutoff with the current of 0.5C(A) at (25±2) ℃, and then start the next cycle，end with the capacity decreasing to 80% of the initial capacity. The number of cycles is defined as the cycle life of the battery.

 

[Supervstech]

As I understand it, a cycle is when battery has a discharge to a point, then is charged back to full, so if a 100Ah battery has 50Ah drains, then is recharged back to 100 Ah, it is a cycle, not a COMPLETE cycle, but still qualifies. Any discharge, followed by a recharge is a cycle.

 

[fromport]

As I understand it, a cycle is when battery has a discharge to a point, then is charged back to full, so if a 100Ah battery has 50Ah drains, then is recharged back to 100 Ah, it is a cycle, not a COMPLETE cycle, but still qualifies. Any discharge, followed by a recharge is a cycle.

Afaik a cycle is always specified to a certain dod eg 80%.
Doing twice a 40% dod discharge/charge is just one cycle

 

[uksa007]

Afaik a cycle is always specified to a certain did eg 80%.
Doing twice a 40% dod discharge/charge is just one cycle

Yep that's correct, however the cell manufacturer usually specify their rated number cycles as 100% DOD as per my post above.

The JK-BMS counts 1 cycle as 100% of batteries AH being consumed.

But you can count your cycles as 80% or whatever you like, if you have some way to keep track of it.

 

[Don B. Cilly]

It's funny though, my Victron shunt reports 12 cycles, in 14 months of usage.
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[Nevadablue]

That’s why Victrons are expensive; they save your batteries by reducing cycles.