TI E2E Community
BQ27500 max pack capacity
Welcome to the Battery Management Section of the TI E2E Support Community. Ask questions, share knowledge, explore ideas, and help solve problems with fellow engineers. To post a question, click on the forum tab then "New Post".
Q: BQ27500 max pack capacity by 313454
Hello, I'm using the BQ evaluation software to configure the BQ27500 system-side impedance track fuel gauge.
In my application the capacity of the battery pack is 49000mAh (7 x 7000mAh packs in parallel) but when i put this value on the "design capacity" parameter using the bqeasy tool there is an overflow error message when the flash is programmed.
If I try to change the parameter using the dataflash window there is an overflow for the a numbers greater than 32767 and the value programmed become negative.
On the datasheet the max value for this parameter is 65535 so why is there an overflow?
Is the max capacity for a BQ27500 32767 or 65535mAh?
If the the capacity max of the BQ27500 is 32767 what could be the solution to gauge a 49000mAH battery pack?
A: Re: BQ27500 max pack capacity by 317599
The limit for our coulomb counting should actually be 32k.
To gauge capacities higher than this, you can mis-calibrate your sense resistor by a certain factor (2x, for example). This will reduce your coulomb counting by 2x.
All your relative values (SOC, time-to-empty, etc.) will still be correct, but your absolute values will be 2x lower so your system will need to multiply the readings by 2.
All content and materials on this site are provided "as is". TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with regard to these materials, including but not limited to all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement of any third party intellectual property right. TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with respect to these materials. No license, either express or implied, by estoppel or otherwise, is granted by TI. Use of the information on this site may require a license from a third party, or a license from TI.
TI is a global semiconductor design and manufacturing company. Innovate with 100,000+ analog ICs andembedded processors, along with software, tools and the industry’s largest sales/support staff.