Other Parts Discussed in Thread: BQ40Z60
I'm using BQ40Z60EVM-578 to evaluate our NCR 18650B, lithium Ion battery, 4 series, so the final output is 3.7v*4.
Power supply: BK precision 1762 DC power supply. Set the output to be 20V, current output is set to max.
Load: 40ohm resistor.
In order to mimic the real world,that is the battery will leak and the terminal voltage will be lower than 3000mV. I intentionally discharged the battery to be less than 3000mV, say 2600mV.
CUV alert comes out, which is what I expected. However, since the voltage is lower than the recovery voltage(3000mV), I actually have no way simply by turning on the external power supply.
According to the TRM (
), Page 11,
Condition 1:
SafetyStatus()[CUV] = 1 AND
Min cell voltage1..4 ≥ CUV:Recovery AND
Protection Configuration[CUV_RECOV_CHG] = 0
How can I increase Min cell voltage1..4 ≥ CUV:Recovery? The charger won't take the power from external power supply due to the CUV alert.
I think the charger should automatically charge the battery. CUV alert should be used to prevent the battery from additional discharge.
BTW, I also found the resistor load isn't able to work with the external power supply. Weird, charging the battery and supplying power to the load should be separate issues. The load should be always allow to work if the external power supply is present unless something catastrophic, such as overheat or undervoltage(power supply)
