BQ34Z100-G1: Saw 0% Health at startup, then it jumped to 100%

Kevin Banks

Prodigy 235 points

Part Number: BQ34Z100-G1

A unit using a BQ34Z100-G1 gas gauge was power-cycled as part of a test.

It reported 0% health at first, but then it jumped up to 100%.

1. Is this expected behavior?

2. Or is it commonly indicative of something being misconfigured?

3. If so, what are typical causes of this?

over 4 years ago

0 Wyatt Keller over 4 years ago

TI__Guru** 105770 points

Hello Kevin,

Did the SOH jump or SOC?

The gauge will take a new voltage measurement when it's power cycled and correlate the voltage to a DOD value for your battery's programmed chem ID. It could be due to a bad chem ID match.

Sincerely,

Wyatt Keller

0 Kevin Banks over 4 years ago in reply to Wyatt Keller

Prodigy 235 points

In this case it was a SoH jump.

0 Vos over 4 years ago in reply to Kevin Banks

TI__Genius 10370 points

Kevin,

SOH is independent of SOC. It relies on running a simulation at 25C and a nominal dsg load (C/5). However, when the gauge is initializing it has not run this simulation, thus it doesnt have a valid value. So it does report 0 until the simulation is complete and initialized.

For that matter you should not use any gauge reported values until the [INIT] flag is set out of good habit.

Thanks,

Eric Vos

Power management

Power management forum

BQ34Z100-G1: Saw 0% Health at startup, then it jumped to 100%