How robust are blue cell power capacitors?

This you know only when you test beyond the specifications of the datasheet. While the full test report is being prepared, hereby a few early test resulst of last week.

First we test some 18500 and a some 18650 cells by charging them at 5C and then discharging them with 1C upto 10C (for 18500) and from 2C to 20C (for 18500). The test setup is as follows:

– The cel is placed in the (airconditioned) room at about 22-24 °C. No extra cooling.

– The test terminates if the cell discharges to its lowest voltage or if a maximum temperature is reached (the the temperature is measured on teh skin of the cell).

– The cells are charged at increasing C-rates up to the maximum allowed on the datasheet.

Below the graphs for a 18500 and a 18650 cell.

Next we went a step further and went beyond the maximum discharge current specifed on the datasheet. So this time from 9C to 20C (18500 cell), resp. 16C to 38C (18650 cell). This time we placed the cells in a heat absorbing foam and we used a ventilation fan.

Below the graphs for a 18500 and a 18650 cell:

The full report will follow.