BQ24610: 2 series battery carger

Hello Kenyo,

Kenyo Tobita said:

Pls advice to avoid IC broken below situation (like EOS durability test).

Can you expand on your test? what were the conditions that broke the U201?

Best Regards,

Christian

Thak you for reply.

This tandem chager has a trouble below situation.

/ Connecting the battery when no DC input.

I can not figure out why only U201 is broken.

Then I will try to see when put the ideal diode for preventing the battery for discharging.

Thanks,

Kenyo Tobita

Hello Kenyo, 

Can you re upload your schematic? I'm having trouble zooming in on the components.

Best Regards,

Christian.

Thank you for reply.

Yes, but I can not know how to upload.

Pls tell me.

Thanks,

Kenyo Tobita

Before_Improvement_SCH.pdfAfter_Improvement_SCH.pdf

I could upload two schematic files before and after improvement.

Before improvement, U201 will be broken by battery attached and dettached continuously like EOS durability test.

After improvement, U201 will never be broken at test above.

Also U201 will never be broken at test above, if the DC input is alive.

I wonder if the root cause of U201 broken is by discharging of batteries. 

If you have some comments, pls let me know.

 I would like to explain our tandem charger from a design point of view shortly.

The power of AC adaptor is smaller than the maximum chraging power two batteries needed.

Then I selected cascade connection of two charger IC using control function of input and charging current.

Control current function of BQ24610 is helpful and matching our stand alone tandem charger without charge control by CPU.

DC input: 19V, 2.0A = 38W

Charge: (16.4V, 1.6A) x 2 = 52W (Maximum)

Hello Kenyo,

Kenyo Tobita said:

Before improvement, U201 will be broken by battery attached and dettached continuously like EOS durability test.

Which battery did you plug in that cause the issue?  J2 or J3?

Kenyo Tobita said:

After improvement, U201 will never be broken at test above.

Also U201 will never be broken at test above, if the DC input is alive.

I wonder if the root cause of U201 broken is by discharging of batteries

yes, This is mostly caused by the discharging of the battery. You said that the device works now, do you have any other questions? If not I will close this thead

Best Regards,

Christian.