MP2659GQ-0000-Z not charging up to full

Battery Management
1

Hello,
We are using the MP2659GQ-0000-Z for charging a 4S battery (16.8V) with an 18V 3A adapter.
I have designed the schematic (attached for reference) based on the EVK schematic provided by MPS.

However, the battery is not charging after 15.8 Volts. When I check the STAT# pin on the oscilloscope, it is blinking at around 6Hz.
My VDPM (TP2) and ACOK# (TP1) pins remain LOW when powered on. The voltage at NTC is 3.4 volts.

Could you please help me troubleshoot this issue?
Feel free to ask if any additional information is required.

Thank you.

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2

Hello,

Thanks for reaching out on the MPS forum!

Are you able to change resistors on your board? If so, I suggest adjusting the voltage divider going to the VB pin so you can see if that is causing the issue. The issue could be stemming from how the MP2659 senses battery voltage upon startup. I believe you can account for this by adjusting the battery regulation voltage.

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I recommend connecting the VB pin to VCC to see if the battery continues charging past 15.8V.

Let me know if you have any additional questions. Good luck!

Best,

Yash