Charge & Discharge

Quality of re-chargeable batteries consists of capacity, retention, cycle life and safety.

 

Capacity, retention and cycle life are related, and therefore it is advisable to determine all results as shown in this complete test program:

 

After a complete test overview has been set, a quick scan program can easily be made.

For instance yearly control of C5 (@ 20 and 0C), Life-cycle and safety device operation.

The results should be close; if not this might indicate a quality problem.

 

 

All tests are according to IEC, except:

 

 Life cycle test which is an economical alternative to the standard that gives a very usable result within a decent time span:

 

Endurance test @ 20C, all cells continuously charge with 1.0 It A until V= -5mV and immediately discharge with 1.0 It A until < 1V0 / cell.

 

Continue this test until capacity is < 50% (from nominal capacity)

 

 The 28 days retention @ 40C is added to give insight into the self-discharge rate. It is a test used to indicate the decrease of capacity in time. Especially for low-self-discharge or ready-2-use batteries the outcome should be over 80%: