BQ24172 charge setting

Lucifer

Part Number: BQ24172

Dear Sir,

So far, we are using CHARGER BQ24172 for our system.

so far, we are measuring our battery capacity. we have got some problem below

1. Our battery can not be charge to 100% . our Icharge=1.7A , so the Iterm shoule be 170mA (1/10 Icharge). so far we found Icharge = 260mA then it will jump to 0mA and will not keep charging (as below battery charge time table). Can I revise the Ich cut off point?

2. Cell voltage adjustment: Our Actual cell voltage is 4.241V. we want to adjust to near 4.2V. may I know how to adjust it ?

Thanks.

over 8 years ago

0 Steven Bangdiwala over 8 years ago

TI__Expert 8690 points

Hi Lucifer,

Please share the schematic. I want to see how everything is setup and also the components used for FETs and inductor. As for the battery voltage, be sure to use 1% tolerance resistors on VFB. Also, set it slightly below 4.2V/cell so that you don't overcharge the batteries.

Regards,
Steven

0 Lucifer over 8 years ago in reply to Steven Bangdiwala

Expert 2600 points

Dear Sir,
thanks for your reminder. I checked the charge table again the Actul Icharge is 2670mA so that my Iterm is 260mA.
I will revise Icharge1700mA to meet Iterm 170mA.
Moreover, I will fine tune the divider resistor of FB first for battery voltage accuracy, Thanks.

0 Lucifer over 8 years ago in reply to Lucifer

Expert 2600 points

Dear Sir,
one more thing , is it possible to adjust Iterm current only not to change Icharge? Thanks.

0 Steven Bangdiwala over 8 years ago in reply to Lucifer

TI__Expert 8690 points

Lucifer,

The only method of modifying the Iterm without affecting Icharge is to disable both the fast charge timer and Iterm by pulling TTC to low.

Regards,
Steven

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BQ24172 charge setting