Disabling Charge Mode to Avoid External Battery Charging

[Gabriel Mergh Oliveira]

Hello Community!

I want to use the npM1100 as a power management device in my project. The external battery to be used is the ER26500 and it is not rechargeable.

If I activate ship mode and put the ICHG pin in ground, can I confirm that the npm1100 will not try to charge the external battery that is connected to it?

Should I then use configuration 3?

[Simonr]

Hi

If you're creating a design with a non-rechargeable battery, I would suggest checking out the nPM2100 which is a PMIC for just that. https://docs.nordicsemi.com/category/npm2100-category 

I will have to ask the developers whether we can confirm that the nPM1100 won't try to charge connected batteries.

Best regards,

Simon

[Gabriel Mergh Oliveira]

Yes, you will check the use of the npM2100 in the project. My real question is whether I could use the npM1100 without it trying to charge the battery.

Best regards,
Gabriel

[Simonr]

Hi Gabriel

Regarding the charging on nPM1100:

If you use a non-rechargeable battery, you can just leave VBUS disconnected altogether, and that should make it not able to charge at all. However, if VBUS is used as I.E. a power source, there is no way to ensure that it won't try to charge the battery on the PMIC itself.

One thing you can do to work around this is to connect a 1kΩ resistor between the NTC pin and GND. A 10k thermistor would be 85°C at 1kΩ, and the PMIC will never charge a battery at 85°C.

Best regards,

Simon

[Gabriel Mergh Oliveira]

Hello Simon, 

I developed a layout with the npm1100, as it is the one I am finding available stock for use. With that, I customized the circuit design so that the battery would not be charged. Could you analyze it for me and tell me if it would work the way I expect, using the npm1100 as power management, but without recharging the battery?

[Simonr]

Hi Gabriel

Can you share some additional information on what BAT_MON and BAT_MON_EN will be connected to here, and how is the battery connected to the circuit altogether, as this isn't clear here and I don't want to make any assumptions when reviewing your circuit. This should indeed make sure the nPM1100 won't try charging your battery.

Best regards,

Simon