BQ40Z80EVM-020: On-Board EV2400 Connection Not Working properly

I attached the battery and still not recognize it.

Do you know the firmware required for bqStudio version 1.3.101 ?

How do I know if it's a power issue? 

Hello Jose,

Even if the BQstudio/EV2400 FW is out of date, it should still recognize that some device is present. When it says "none", that suggests no communication is happening at all, which is usually because the device is unpowered. You can check with a scope if you have one. If you have an external EV2400, it would be best to try with that first. If not though, it should be no problem. If the button/pack voltage doesn't work for you, let me know. 

I followed the EVM user guide for connections and this is the set up I have right now.

J18 pins 1 and 2 are connected, J19 pins 1 and 2 are connected, and J22 pins 2 and 3 are connected.

I have the battery attached to 1P and 1N, and I have shorted from 7P to 1P. I have SYS PRES and PACK - connected. I have a load connected to to PACK+ and PACK-

I literately do not know what else to do to get it recognized.

Hello Jose,

The configuration does sound correct. I think the best way to debug this would be to use a scope/meter to start probing certain pins. For example, one thing that can happen is that the shorts may be broken in the chain from 1P up to 7P, so you can measure the 7P/BAT pins to see if you see the voltage you expect. Also, on pack+, you say you have a load connected? I would suggest connecting a power supply that is nearly/matching the battery's voltage. The symptoms here sound to me like the gauge is in shutdown and hasn't been able to wake up. Applying a voltage across pack or holding the WAKE button(shorts BAT to PACK+) should allow the gauge to wake up. 

Lastly, what is the voltage of your battery? Is it below the 2.2V shutdown threshold? If everything else doesn't work for you, can you try adding another series cell? Or using the voltage divider for a cell simulator? The BQ40z80 is not really designed for single cell use. I think it should still recognize, but I'm not 100% sure. Let me know if this still doesn't work and I will acquire a board and try to re-create your setup.

thanks,

Alex M.

Hello,

What power supply should I use to connect between PACK+ and PACK-. Do I use a battery charger or a DC source? I don't want to damage the board.

If so, how do I do a proper set up for the supply so that I don't damage the board.

Hello Jose,

Either is fine as long as the voltage is close to the bat voltage or it is current-limited. So if you had a 1s li-ion battery you could use DC power supply set to around 4.4V with a <100mA limit just to start with, and ensure everything powers up. You could ramp the current later for charging purposes. The battery charger should be similar; ultimately PACK+ is meant to connect to a charger and load. Holding the wake button shorts BAT to PACK+, which is why that usually works as well. 

However, I was able to confirm that this board cannot be used for 1s-cell configuration. When you apply a pack voltage, that should wake up the board regardless, but you will likely see some strange behavior/safeties flagged in BQstudio. If it doesn't wake up, it may even be expecting a higher pack voltage for a 2s system at least. Do you plan on using this board with a 1s configuration or are you just starting with 1s for testing? 

thanks,

Alex M.

Hello Alex,

I attached two cells with same set up I had, and it did not work. I even applied 4.7 V across PACK+ and PACK-, and it does not get recognized. I truly believe there's something else. I am running out of options here. Would you please try my set up?

Also, how do I make sure I have the right version of the software and the right firmware installed? There has to be something I am missing.

Do I need a driver for EV2400? If so, where can I find it?

Also, I checked the voltage across PACK+ and PACK- while pressing down the wake button and it reads the same voltage as the two cell batteries, about 7V.

There has to be something wrong, the board and PC cannot communicate through USB connection. I might be missing a driver or something.

Hello Jose,

I was able to find the same EVM and tried to re-create your setup. I made a 2s configuration using a power supply and a resistor divider. I also did not use a pack+ voltage because I prefer to use just one power supply and hold down the wake button. While holding wake and opening BQstudio, it was able to pick up. From actually using the board though, I would suggest you double-check your jumpers. The instructions say to connect J18 and J22 to pins 1 and 2 and the other to 2 and 3. That is confusing in my opinion, make sure both jumpers are on the lower 2 pins (closer to the EV2400 chip). As for the drivers, they should automatically install the first time you connect according to the guide. I didn't have to take any other steps, but I likely already have them(drivers) in any case. 

Besides the jumpers, I also like testing by using the power supply on BAT because I can tell if the gauge is powered by the current draw. my divider drew about 8mA, but I could tell the gauge was on because it was drawing up to 10mA, so that may be worth trying with a power supply for now. Also, another thing that has given me problems in the past with these gauges are the large amounts of connections on the bat pins. Since you need to short every single unused CELL connection. If even one short is bad, it won't pick up. Also, check that ground is connected well. 

I think the fact the the voltage is correct when measured across PACK+ suggests your connections are okay though, but it is always worth checking. You can also check drivers in your device manager. I believe the EV2400 should be under "human-interface-devices". Or you can try a different computer if one is available. 

thanks,

Alex M.