MP2615 Auto-recharge does not work

Currently, We are using an MP2516 to charge two batteries in series.
The auto recharge sometimes is getting stuck and does not work, it requires resetting the board or polling the Enable pin sometimes resumes to work.
The IC is set to work between -20 and 80 degrees, the Icc current is set for 0.1A.

Hello gabrielac,

Could you elaborate on what you mean by the auto-recharge is getting stuck?
Is it stuck in CC or CV?
Does it not even start?
What is the device is doing when it is stuck?
What is the battery voltage at when recharge should start?
Is your timer capacitor value set too high?

Regards,
Vinh Tran

Hi Vinh Tran,

We have many devices that are working properly in the field, doing the recharge cycle.
But there is one remote unit that sometimes does not enter into the recharge mode cycle.
I can remotely monitor this unit, and I can see the unit doing the recharge cycle by looking at the ACOK pin, CHGOK pin, and battery level through an ADC.
What is happening in this unit is after finishing a recharge cycle ACOK = low, CHGOK = high the battery starts slowly to discharge until became 0% (less than 6.75V) and does not enter into the recharge mode again.
It stays with ACOK = low, CHGOK = high, Battery level 0%.
Reset the device or toggling the Enable pin sometimes resume to recharge again.
The device has two cells of 4.2V (SEL = 0V, CELL = 0V).
Ctmr is 4.7uF, trickle charge time is set to 295 minutes.
Unfortunately, I cannot check if it is stuck in TC, CC, or CV.

Regards,
Gabriel Costa