Power consumption in Sleep mode (Vbat /battery powered)

In HTCC-AB01,the typical value of Power consumption in Sleep mode is 11uA in spec.

However, my measurement is different:
Vbat Sleep mode Current (Vbat /battery powered)
3.5V 10.7uA
3.7V 10.9uA
4.0V 22.9uA
4.2V 27.1uA
Which means it will almost triple Power consumption when li-ion fully charged.
Is it normal? where the power was gone and how to reduce it?

Also,I use a tweezer to short the charging IC input (Vs) to GND but the current does not change.

hi,

you can refer this picture.

The Sleep mode (Vbat /battery powered) show in the picture is 11uA.
I can get a similar current(10.9uA) when Vbat is 3.7V.
However, it becomes 27.1uA when Vbat is 4.2V. Is it correct reading?

Yes, “27.1uA when Vbat is 4.2V”.

We recommend using 3.7V

On my HTCC-AB01, the BR0 is connected to AO7801 S1, not D1.
It creates a sink current to the ADC pin and pullup the Vdd from 3.3V to 3.4V.

After I remove BR1 and use a jumper wire connect ADC to D1 , the Sleep mode Current (Vbat /battery powered) at 4.2V will be normal and 3.3V power does not goes higher.

Also, I found out HTCC-AB01 using 2 10k resistors as a voltage divider, but HTCC-AB02 using 2 100k resistors as a voltage divider. I replace 10k with 100k without any issue and reduce current consumption during battery voltage sampling.
image

hi,

Thank you so much for your creative opinions.

Actually, We were also considering this issue some time ago. Your ideas coincide with ours.

We will also produce the latest hardware version in the near future.

Hi Jason,
if you are going to change the PCB for the next version please expose the enable pad on the onboard regulator so that an external one can be added as a backup. (see the other thread on secondary backup battery)

thanks

OK. We will add this in the next PCB version

I have a similar issue with my HTCC-AB01 consuming higher current in Sleep mode.
Do you have a sketch of where the AO7801 and the BR1 are located on the board so that I can check whether mine has a connection to S1 rather than D1?

Just reminded that we are talking battery power.


Here is how I modified my board.
image

Thanks, that is perfect. I have two identical circuits and I can see one draws about twice the battery current as the other, so I will now check the board to see if the thirsty one has the S1 connection instead of the D1 connection.