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BQ25606: BQ25606 Charging Current

Intellectual 290 points

Replies: 3

Views: 45

Part Number: BQ25606

Dear,Sir

I have been using BQ25606 IC in our PCB for single cell configuration.

IC Is working and showing the detection of the battery as well.

My query is ,i am  not getting the charging Current as per the set Values.

When the battery voltage are 3.0 or 3.2 V i get around 0.8 to 1.2 A of current.And this current gets decreasing by passing of time ,i know that as the battery voltage will increase the charging current would decrease.

But still the pace of decreasing the current is like within the span of 1.5 to 2 Min the charging current reduces to 0.5A.And At around 4.0 V the charging current is 0.2A.

I am attaching the schematic that we have developed please have a look..!!

Waiting for your response..!! 

  • Hey Tirthal,

    Can you measure the voltage as seen from the BAT pin of the charger (not your battery)?

    Regards,

    Joel H

  • In reply to Joel Hernandez II:

    Dear,Sir

    Below are the measured Voltages :

    Test 1 :

    1)Battery Voltage :  3.45 V(Initially)

    2)Charging IC Voltage (Across C15)  : 3.89 V

    3)Voltage On Battery : 3.576 V

    4)Charging Current (With Multi meter ) : 0.372 A

    Test 2 :

    1)Battery Voltage :  2.6 V

    2)Charging IC Voltage (Across C15)  : 3.0 V

    3)Charging Current (With Multi meter ) : 1.3 A 

    Charging current decreases once the battery voltage reach 3.0 V to around 1.0 A to 0.9 A.

    Hope this Helps...!!

  • In reply to Tirthal patel:

    Hey Tirhtal,

    There are five ways in which the charge current can be reduced from the setting value:

    1) VINDPM - When the input voltage (seen on VAC and VBUS) falls to the higher of 4.3V and VBAT + 300mV, the charger will reduce the charge current.

    2) IINDPM - When the input current as compared to the reference set on the ILIM pin resistor setting is hit, the charger will reduce the charge current. 

    For the above two, output power plays a major role. If you notice that the current decays somewhat linearly as the battery voltage increases (i.e. from 3.0V to 3.3V to 3.7V as measured from the VBAT pin of the charger), then you are likely in a DPM state above.

    3) TS JEITA COOL or WARM - When the TS network %REGN value is either in the TCOOL region, the charge current is reduced to a fixed %ICHG setting. So it should not shift much across battery voltage. TWARM reduces the battery regulation voltage to 4.1V, which means you will enter CV mode sooner. See CV mode below. 

    4) CV mode - Here the battery charging voltage is regulated, instead of the battery charging current, and thus the current decays as the battery voltage increases. 

    5) Thermal Regulation - If the IC junction temperature exceeds 110degC, the charger will also reduce the charge current to minimize the internal power loss.

    Regards,

    Joel H