BQ34110EVM-796: Unexpected Current Detected [LUCD] during Learning Charge Phase of EOS Learning Cycle

Mark Watson

Part Number: BQ34110EVM-796
Other Parts Discussed in Thread: BQSTUDIO, EV2400

Hello,

I am using the BQ34110EVM with an EV2400 and bqStudio to gauge a PbA battery. I am trying to execute an EOS Learning Phase (a manual Charge-before-discharge), so I give the EOS_EN command, followed by the EOS_START_LEARN command. The [LCMD] and [LCHG] bits in the EOS Learn Status register both set indicating the device is ready for a user controlled charge; however, I keep getting the Unexpected Current Detected error ([LUCD] and [LFAULT]). Of course the Learning Phase is then aborted automatically. The datasheet says this bit will set during the charge phase if a discharge current above a certain threshold is detected, but the current readings are all indicating a valid charging current. Can anyone tell me why I keep getting his error?

Thanks.

Mark

over 7 years ago

0 answer over 7 years ago

TI__Intellectual 1735 points

Hi,
The actual current may not the same with the current read from the register. You can try to use a multimeter in series with the charging or discharging path and see if the current is exactly the same with the reading value.

0 Mark Watson over 7 years ago in reply to answer

Intellectual 530 points

Yes of course. I am already doing this.

0 Mark Watson over 7 years ago

Intellectual 530 points

Does anyone have any other suggestions?

0 -Terry over 7 years ago in reply to Mark Watson

TI__Expert 3990 points

Hi Mark,

When in charge mode, the gauge will detect charge termination, then expect charging to be stopped within a time set by “Learn Request Time”. Since the gauge does not have FET control to stop the charging itself, it relies on the user to stop the charging once fully charged. You might see if this could be the cause of your issue.

Thanks,

Terry

0 answer over 7 years ago

TI__Intellectual 1735 points

Hi
Could you show me the connection state of jumper J2, J5, J10 and J8 on the EVM?
If both J10 and J8 is connected, this may a reason for this condition.
Could you upload your .gg.csv file (log data) from bqstudio? I will test with a bq34110evm with the same configuration with your board.

0 Mark Watson over 7 years ago in reply to answer

Intellectual 530 points

Terry,

I know J2 and J5 are set appropriately (12 V PbA). The board is not clearly labled, but it looks like J8 is labelled "LOAD" and J10 is labelled ""LEN." I have both of these jumpers connected. Why would this configuration give me this error?

Mark

0 answer over 7 years ago in reply to Mark Watson

TI__Intellectual 1735 points

Hi,
You can check the voltage on LEN pin to see the voltage level of LEN. If it is high, the Q4 may open and cause current flow through R21.
You can also upload your register configuration and I will re-test the EVM with the same configuration with you.
EOS_EN: End-Of-Service Determination Enable
Note that if [EOS_EN] is changed directly in data flash, then the device should be reset for
the change to take effect.

0 Mark Watson over 7 years ago in reply to answer

Intellectual 530 points

Terry,

I still do not understand why current flowing through R21 would cause this error. Could you please explain further?

Thanks.

Mark

0 answer over 7 years ago in reply to Mark Watson

TI__Intellectual 1735 points

Hi,

I have tried to send the two command on EVM and the LUCD and LFAULT is not set on my EVM. Could you kindly upload your .gg.csv file exported from data memory and I will test with your memory configuration?

Power management

Power management forum

BQ34110EVM-796: Unexpected Current Detected [LUCD] during Learning Charge Phase of EOS Learning Cycle