What is the battery use when 12 v is supplied to vin?

Hardware
1

It seems like my electron is running steadily on the 13vdc power supplied to vin. I thought that if I had the lithium battery attached it would only draw charging current from the VIN. The red charging LED is not coming on. Should it not run primarily on the battery when the battery is connected?

2

Given that the BQ24298 has a maximum operational input voltage of 6.2v, I would disconnect your 13vdc from it as soon as possible and feed it with something more like 5v.

It does have protection (non-operational) up to 15v, but it's in overvoltage protection lockout mode when it's above 6.2v - see http://www.ti.com/lit/ds/symlink/bq24298.pdf

Edited by BDub

The Electron uses the BQ24195 which is rated 3.9V to 17V Input Operating Voltage Range. Particle recommends keeping the voltage under 12VDC due to limited heat sinking capability of the Electron (YMMV if you can provide better heat sinking).

3

Thank you for your response. I will use 5 volts in the application and I’ll try the 5 volts ASAP.

Tom

4

Hi Hugo,

Thanks for the advice. I have 4.99 vdc to VIN now. The electron is drawing around 90 ma most of the time, while it is trying to connect to the cell network. (Green LED flashing continuously). I am out of cell phone range for a while. Should I assume that the battery is being charged at the same time as the VIN is powering the unit? The documentation tells about the Battery powering the unit when the electron is hooked up to the USB port because the USB is known to have limits on its supply of current, but what is supposed to happen when the electron is connected to 5 v VIN and the battery (with no USB)? When the electron needs hundreds of Milliamps will it get that current from the battery if a battery and VIN is connected? When we put the electron in sleep mode, will the VIN be charging the battery? I am hoping that whenever the electron needs hundreds of MA of current it will go after the battery to supply it. I am looking at the VIN mostly as a charging voltage. Is it correct to think of it in this way when a battery is connected to the electron and the VIN?

5

the docs seem to suggest that you are correct:
“The Electron uses TI’s BQ24195 as the power management and charging unit. This PMIC intelligently sources power from either the VIN pin, the USB port and/or the LiPo battery. When all the power sources as connected, the unit tries to source power from the USB or VIN as default and continues to charge the LiPo battery. When the battery is completely charged, the power is then sourced from USB/VIN alone. If there is a power deficit (which generally occurs during cellular radio transmission), the additional power is then sourced from the battery as required. The unit can also seamlessly switch back to the battery when other sources of power are suddenly removed.”

1 Like
6

Thank you Hugo and Brian,
After doing some more reading myself, I note that the electron data sheet says on page 20 of 34 that The PMIC defaults to a 500 ma current limit for both VIN and USB, because they are connected together. “A user can always adjust these parameters via software.” I would like to adjust the parameters to limit the current drawn on VIN to 100 ma if possible whether the USB port is detected or not. Can you provide us with the code to set that limit? If 100 ma is not possible, I’d like to set the limit to 150 ma. Can these parameters be set using the CLI?

7

Here is some rudimentary info about that
https://docs.particle.io/reference/firmware/electron/#pmic-power-managment-ic-

This together with the PMIC datasheet and the open source code and inline comments will give you some idea

1 Like
8

I’m reading your suggestion regarding to 13V dc/VIN pin, but I’m wondering if I’m missunderstanding something, couse the electron datasheet suggest no more 12V and 10W, meaning that if I provide 12V/900mAh it would be fine. But I’m worried to try that after reading your seggestion; I just want to know if I’m missing something.

Thanks

9

Is fine. It can accept higher input voltage but the buck converter would generate more heat and Particle wants you to be on the safe side and says don't feed Vin with more than 12v.

https://docs.particle.io/datasheets/electron-(cellular)/electron-datasheet/#technical-specifications

10

Ill try that too … thanks a lot for the responses even in new years eve.

Have a nice, cool and full of funny and amazing projects in 2018.

11

Hi there… taking advantage of this thread as it seems relevant.
Is it possible for the VIN pin to output even a small amount of current if only the LiPo Battery is connected? I read the docs and the Electron block diagram suggests that the LiPo battery is not connected directly to VIN pin but to the power management block.
My application uses the Electron connected to a 5V source through VIN and uses the battery as back up when the 5V source in VIN is absent.
However, I just want to make sure that the circuit connected to my Electron is not draining unintentionally power from the battery when 5V in VIN is absent. Thanks for the comments

12

There is a diode on the Vin input pin which should prevent current backflow.

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You would need the diode part number to know the specs on that actual diode though.

13

If you are asking whether Vin will source power while your Vin connected supply is absent but other components connected to Vin are sinking current, then: No

If you want to have LiPo power for other components, then you can use the unpopulated Li+ pin (next to Vin -
but add a protection diode to prevent back feed) or use 3v3.

14

Thanks¡

15

The Electron uses the BQ24195 which is rated 3.9V to 17V Input Operating Voltage Range. Particle recommends keeping the voltage under 12VDC due to limited heat sinking capability of the Electron (YMMV if you can provide better heat sinking).