BMS-design for a portable standalone device

Florian, hello and good morning.  Please allow us a few business days to research and get back to you.  There are a few groups that I'll need to check with to determine if we have a solution that fits your specifications. 

Best Regards,

John Fullilove, Texas Instruments

Hello John,

thanks for looking into it.

Looking forward to hear your recommendation.

Hi Flo,

I can help with the battery charging but I need some information.  As a quick reference, our battery chargers come in two types, power-path and non-power path.  The non-power path chargers' linear regulator or switching converter output connect directly to the battery. The power-path chargers have an internal battery FET from the regulator/converter output (OUT/SYS)  that provides charge current to the battery.  The regulator/converter output provides a minimum system voltage to the OUT/SYS pin when the battery voltage is below that voltage and then tracks the battery voltage up to its final charged voltage.  So the OUT/SYS pin output of a power path charger has a voltage range of 3.5V to 4.2V.  The chargers with I2C configurability allow you to change that 3.5V value slightly.  Also, with power path charger, you can more accurately terminate charge.  More info is available on our website.

I don't support protectors or gauges but, in short, protectors are usually included in the battery pack itself so you may not need to design.  Gauges are mini processors and in general require host I2C communication.  There are a few that are what we call 'standalone'.

So, with that brief introduction, 

1. what is the charge current you desire, keeping in mind that charge time =~ 1.3 * Ahr / (I-CHRG).

2. Do you have host software and I2C capability?

3. Does 'Output: 3.3 to 5V, 0.1 to 0.5A' mean you also need a dc/dc converter to provide between 3.3V and 5V to your system?

Regards,

Jeff

Hi Jeff, 

thanks for the information. 
 

1. The charging current would be between 0.5 and 2.5 A. The charging should be possible via a USB port or a power supply.

2. Yes, I am using an MC with I2C capability.

3. Yes, I need a DC / DC converter to supply peripherals with accurate voltage.

Greetings Flo 

Hi Flo,

For the charger, I recommend the BQ25601 family of 3-A power path chargers.  The BQ25601D has D+/D- that will auto detect the USB source per BC1.2 spec.  It will charge in default mode but you can change the charge current via I2C.

I am not the expert on fuel gauges so I will forward this thread to that gauge team.

Regards,

Jeff