BQ34Z100-G1: Scaling factor for external gauge

Kurtis Unger1

Part Number: BQ34Z100-G1
Other Parts Discussed in Thread: BQ34Z100

Hello - I would like to use the BQ34Z100 as an external fuel gauge for a 24V, 105Ahr, 8S1P LiFePo battery.

I found the the scaling article: www.ti.com/lit/an/slua760/slua760.pdf
But unfortunately I'm not quite clear on what is actually required to scale the EVM for the higher 105Ahr capacity rating.

Is it simply 105/29 => 4x

So all the scaling will be 4?

Thanks

over 4 years ago

0 Nick Brylski over 4 years ago

TI__Mastermind 19195 points

Hi Kurtis,

You would scale the capacity by 4 yes, what is max current in this system? May also need to scale.

Best regards,

0 Kurtis Unger1 over 4 years ago in reply to Nick Brylski

Prodigy 50 points

Thanks for the reply.

The max current is .5C (50A) and that's a huge stretch.

So I think the capacity is the largest scaling factor at 4x and I should use that.

0 Wyatt Keller over 4 years ago in reply to Kurtis Unger1

TI__Guru** 105590 points

Hello Kurtis,

Yes, it looks like a factor of 4x would work for your system, just make sure to follow the steps in the guide you linked (SLUA760)

Sincerely,

Wyatt Keller

Power management

Power management forum

BQ34Z100-G1: Scaling factor for external gauge