BQ34Z100-G1 Single Li-Ion standalone advice

Hello all,

I still have not found any information on the correct parameters to fuel gauge a single li-ion battery.

Does anyone have some advice, or ideas that would work? Right now, I will take any idea I can get.

Thank you
Anthony.

Hi Anthony, (Sorry for the long and somewhat late reply!)

Yes, for development using the bq34z100-G1, you'll need an EV2300 or EV2400 adapter to work with the chips. This is because TI's advanced Impedance Track fuel gauges require a lot of configuration to work properly, including internal chemistry data (OCV curves and internal resistances). Additionally, you'll need a means to calibrate the gauges, and have a means of logging the gauge's data to ensure the proper chemistry information was selected.

The EV2300 is $100 cheaper than the EV2400, but needs manual installation of x64 drivers. You might be able to find other units on eBay, but they're rarely available and the pricing might be only slightly less than TI's own. (That said, I found that the bq2026EVM is priced at $75 USD and it comes with the EV2300; I haven’t bought this myself so I am not sure whether that price is 100% accurate.)

Before I give you any other specific alternative gauges and set-up information, what sort of design configuration do you have in mind?

• Are you using a 1-series (1SxP configuration) or multi-cell configuration? If you are using more than 1 cell in series, how many? Single-cell gauges are generally much easier to configure than multi-cell gauges, and some single-cell gauges only require ~5 parameters to be configured (at the expense of cell choice flexibility).
• Do you intend to have the fuel gauge reside on the motherboard (system-side), or the battery pack (pack-side)?
• Do you already have a protection circuit in use, or do you want to have the gauge perform both gauging and protection?
• Do you absolutely need gauge-based LED bar graphing? For gauges that do not support built-in graphs, the host microcontroller simply needs to read the gauge’s State of Charge register and translate it into an LED bar graph.

Regards,
Jason

Hello Jason,

Thank you for the reply, and it is OK about the late reply. Sometimes I can be impatient, I'm sorry if I was.

I was looking at maybe getting it from Ebay, but I have not decided yet.

The configuration I had in mind was;

1 single, Tenergy 2600mAh (MH48285). The battery is not set in stone, I have not ordered them yet. So I could change it if is needed

I am planing on putting the charging, fuel gauge, protection, and 5V @1.5A output on a board that also has the 18650 battery sled. So I would have a self contained, portable power supply. 

I don't have a preference on what parts are used, just so they do the job.

I dont have to have a LED display/graph. I was only looking for one with LEDs for the simplicity. 

I hope this helps. 

Thank you

Anthony

Hello Jason,

Just an update. I was able to find a EV2300 from Ebay for $35 shipped. So I can now say I am a proud owner of a fuel gauge adapter.

Thanks
Anthony

Hi Anthony,

Great to hear you've gotten a good deal for an EV2300! Be aware that the EV2300's I2C port doesn't have built-in pullup resistors (the SMBus and HDQ ports do, however).

When you say 18650 battery sled, do you intend for the 18650 cell to be removable/in a battery holder, or permanently soldered into the circuit?

Regards,
Jason

Jason,

The battery sled would only allow simplicity. The battery would stay with the charger, fuel gauge, protection, and 5V DC-DC. The only time the battery would be removed, would be when the battery goes bad. I chose a sled so I dont have to worry about soldering to a battery, I dont like things that can go BOOM if I heat them up to much.

Thank you

Anthony

Hi Anthony,

With a non-removable battery, you do have a quite a few choices available, in terms of fuel gauge/protection, charging and DC-DC conversion (and TI has solutions for all of those!).

I presume that your design is more targeted for a very small-scale run for personal projects?

Regards,
Jason

Hello Jason,

That is correct. I would only be making a maximum of 3 boards.

Thanks

Anthony