This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

BQ27426EVM-738: Stuck on the charge step during the learning cycle procedure

Part Number: BQ27426EVM-738

I am doing the automated learning cycle. Battery capacity is 3500mAh, with a float voltage of 4.35V.

After 22 hours of the learning cycle, the BQ Studios GUI is showing 99% and won't move on to the next step. The power supply shows 4.35V, the GUI shows 4.35V, and the current is well under the termination current (its 1mA).

I tried changing the Data Memory > Chem Info > Taper voltage to 4.34V and also changed the V at chg term to 4.34V.

Does this have something to do with the FC bit? I thought the FC bit was enabled by default?

(I also filled out the parameter Q&A. Taper rate is the default 100)

  • Please make sure that the gauge is still in discharge state when the current drops below the taper current which is set by taper rate. Check the Quit Current setting. Also make sure that the gauge won't enter sleep mode when the current drops just below taper current.

  • gauge was still in the discharge state, gauge isn't in sleep mode. How do I check the quit current setting? I don't see it in the registers or data memory tabs. Another detail I saw is that it says "cycle state: connect charger now.". Is it possible that its still waiting for a charger? I'm using power supplies connected to the relays that are connected to the gauge. Is there another way I can tell it that a charger is connected?

  • Quit Current is in class "Current Thresholds", block 0, offset 4. It's C/25.0 by default.

    If the gauge doesn't detect a full charge, then the gauge wasn't actively in discharge state and/or the current didn't taper off within the correct voltage range (it must be above Taper Voltage (class "Chem Data", block 0, offset 8). Note that the current must be above the Quit Current threshold setting and below the Taper Rate setting for at least 2*40 seconds for the gauge to detect a full charge.