Advice for my Battery Management/Charging System

Question

I am working on a battery management or charging system for a 3s2p battery topology. It will be used in a project where AC power from an alternator is rectified to DC power and is used to power sensors. The batteries will be used to store excess charge in case of any downtime and the power supplied from the alternator cuts out, in which case the batteries should make up for the drop in power.

I have 6 Samsung 18650-type battery cells (datasheet here). The alternator is small and relatively low-powered. I heard from a colleague that Texas Instruments and other similar manufacturers produce pre-assembled battery management system (BMS) ICs. I also researched and found out about Texas Instruments and Analog Devices’ PowerPath technology for through-put charging, and I would want to have a technology like this in my device for maintaining continuous DC power to sensors.

I was curious if something like 6x BQ21080 ICs would be appropriate for handling these requirements while also allowing for cell balancing, or if something else is more advisable. I have been suggested the BQ24610 module for my purposes by someone at Texas Instruments, but I am skeptical if it is exactly what I need.

Could anyone help me with this?

Answer 1

I was curious if something like 6x BQ21080 ICs ... for cell balancing

1. That's a charger, not a BMS. A charger doesn't do balancing*. A BMS does.
2. That's a 1-cell charger. You have a 3S battery. Won't work.

You need both a BMS and a charger.

• Charger, limits the current and regulates the voltage to what the battery needs
• BMS, turns off the battery current if required to protect each cell

the BQ24610 module

That will work as a charger, but it's not a BMS.

As I said, you need both a charger and a BMS.

(*) With some exceptions.