MSP430G2001 or MSP430G2210 battery gauge

Jared Becker

Other Parts Discussed in Thread: MSP430G2210, MSP430G2001

Hi team,

Is it possible for the MSP430G2001 or the MSP430G2210 to provide any sort of fuel gauge reading for an alkaline battery? I suspect the answer is no, but I want to verify that there is not a way this can be done.

Thanks,

Jared

over 8 years ago

0 Leo Bosch over 8 years ago

Guru 23000 points

You can use a RC combo and measure the charge/discharge time of the capacitor. Not very precise but gives a sort of fuel gauge.

0 Ilmars over 8 years ago in reply to Leo Bosch

Guru 46710 points

Other option would be to use external battery gauge IC.

0 Jared Becker over 8 years ago in reply to Leo Bosch

TI__Genius 11495 points

Hi Leo,

This seems like it would work. I already looked into external battery gauges, but a cheaper discrete option is desired if its possible.

Based on the following diagram, I have a couple of questions.

1. Is this the correct setup you had in mind for the RC combo? (Please mention corrections I should make if you seem them)

2. Which pin should this setup be connected to on the MSP430?

Thanks!

Jared

0 Leo Bosch over 8 years ago in reply to Jared Becker

Guru 23000 points

Jared, almost.

A ceramic capacitor has a smaller tolerance and temperature coefficient, so I would take a 0.1-1uF capacitor. Also, when using a large capacitor, the current must be limited by an additional resistance, this resistance decreases the accuracy.

You can use any port pin, if you have two port pins free, you can measure charge and discharge, it is more accurate, but only charge also going well.

Leo.

0 Ilmars over 8 years ago in reply to Leo Bosch

Guru 46710 points

SLAA294 application note describes "how to build comparator ADC" in details. Thou it is about NTC measurement, however same RC rules apply

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MSP430G2001 or MSP430G2210 battery gauge