Did you met some solar battery supplier who said theire cycle lower than 6000? It is a traps that most of the battery manufacturer who always say their cycle is more than 6000, even 12000times, but it is true?
Marketing ≠ Technical
Usual we have two standards to assess the cycle of batteries. One way is to define it as deep charge and discharge, while the other is to calculate the total accumulated charge and discharge cycles when the battery is shallowly used.
However, those in the technical field understand that shallow charging and discharging have a lesser impact on battery degradation compared to deep charging and discharging. So, even if a pack manufacturer can only guarantee 6000 full charge and discharge cycles from the battery cell sources, the solar pack manufacturer may boldly claim a promise of 10000 cycles.
But for the users, such warranty promises often lack actual test data support and are based solely on the integrator’s self-assessment.
This kind of vague definition of battery cycle numbers is much more serious in the consumer energy storage field, as resdential solar users have almost no understanding of battery cycle numbers, or even the products themselves.
However, B2B users, such as large-scale energy storage owners, are usually experienced and demand the use of “technical language” when defining battery charge and discharge cycles.
The intermediate user group, such as commercial energy storage owners, mostly remains in a state of unclear understanding regarding battery charge and discharge cycles.
Even some of the top-selling household energy storage brands, such as “unlimited cycles” or “12000 cycles warranty at 2 cycles per day,”
Are they kidding?
Why thing going like this?
when there are warranties available for 10000 cycles, 12000 cycles, or even unlimited cycles, why would a user choose one with only 6000 cycles?
In a buyer’s market, if you don’t speak according to the customer’s logic, the customer will abandon you.
If I have the decision-making power over product definitions and market promotion, I would prominently display ‘unlimited warranty’ on all external promotional windows, to greatly capture the minds of customers.
Battery Testing
Battery cycle testing is time-consuming. If a 1C rate is used for charging and discharging tests, one times complete process would theoretically take at least 3 hours. Assuming automated testing equipment is used, you can test a maximum of 8 charge-discharge cycles per day, which amounts to 2920 cycles per year.
Testing for 10000 cycles would theoretically require close to 3.5 years, while testing for 15000 cycles would require close to 5 years.
So, the question arises: for some cells claiming long cycle life, where do the testing data come from, some solar battery manufacturer even only established for a couple years
Battery cycle testing takes time. The common practice in the industry is to conduct actual tests for the first 2000, 3000, and 6000 cycles, while the results of subsequent cycle tests are based on the company’s self-assessment of the coupling curve of battery cycle and capacity decay.
So it is hard to believe it if the process is depends on the calculation instead of reality, so for the solar buyers, some real testing like scan qr code, testing record, certificate may more important instead of focus on the cycle times