BQ34Z100-G1 reliability during long time without charging

Hi,

Could you advise please?

Moroever, i have other important questions regarding this component.
Could you give information about the SOC if we disconnect or change the battery. How many times it takes to get a correct prediction of SOC in case of normal use. Can it help to consume current on the battery to improve the time of good SOC and in that case how long do we need to consume. If you have other recommandations, please give us.
Other important point, our system use BQ34Z100-G1 connected away from the battery and between battery and board we have input protection and deepthly discharge MOS protection so almost 2 RDSon. Cou you advise about SOC prediction reliability in that case please?

Many thanks for your fast answer.

Best Regards

Renan

Renan
Teh bq34z100-G1 is considered to be a 5% accuracy gauge for high cell packs where there is no cell balancing. It can handle your charge and discharge levels, but you will have to use current / capacity scaling due to the 110Ah capacity requirement. It is preferred to fully charge the pack for the best accuracy and the gauge will handle the partial charge and discharge profiles better for the Li-Ion pack . PbA cells rest to a high level after discharge and this can affect SOC accuracy for Impedance Track gauges, because they adjust the capacity based on the OCV during rest periods. I do not understand the comment about MOS protection between the cells and board. Are you saying that the gauge does not have a direct kelvin connection to the cells? If so, this will have a negative impact for IT gauges as it will affect the ability to update the Ra table accurately. I will contact you offline to discuss how to best support this application.
Tom

Hi Tom,

Many thanks for your answer.

Regarding accuracy, is 5% for both Li-Ion and PbA as you mentionned PbA it's worst?

Regarding the MOS protection, in fact our customer wish to protect PbA batteries againt deep discharge and wants less than 20µA of leakage current so we can't directly connect BQ34Z100-G1 to the battery.
Other solution solution to limit current consumption is perhaps to disable the chip with the CE pin. Pin description is very limited in datasheet so could you advise if there is any risk disabling the CE pin with battery still connected to chip. I suppose if we can do that, consumption is lower than 30µA, could you confirm please? In that case is Ra table and Qmax lost?

Moroever we want reverse polarity protection so we have one MOSFET on negative terminal between BQ34Z100-G1 and battery. MOS will be selected with lowest Rdson as possible. Do you have experience on that case of application and so could you advise about accuracy?

Last question, in case of new installation or replaced battery (solar panel charged battery), how does works the SOC prediction until a complete charge or disharge profil will be done, do we need to consumme to help prediction or just reading voltage and nominal current can be enough to give back a SOC prediction?
I ask you that because in our application we could have the case of system installation during winter and in that case it is possible battery won't be fully charged until several days but we would like to know if, with golden file, accuracy could be high enough for SOC prediction and if there is a way to improve that (consumption for example to see current and voltage).
We would like to record data of calibration depending on each battery then send this information from microncontroler to BQ34Z100-G1.

Many thanks for your fast answer because we really need to be sure of that to finish our choice with BQ34Z100-G1

Renan