Questions about Li-ion battery charger and battery monitor c

[jolin]

I want to build a system powered by 14.8v Li-po battery pack or mains power (selectable power path). When the mains adapter is connected, the battery will be charged and the system will be powered from the adapter.

I've found a family of standalone charger chips by Texas Instruments doing exactly that. It's the bq246xx. This family has some features like over/under-voltage/current protection.

Since the battery I'm using is a 14.8v 4s Li-po battery I must use a cell balance chip. I found this one bq76920 by Texas In. Balancer chips also contain similar features to the charger chips (o/u-v/c protection).

So my question is: Do I have to use both a battery charger and balance/monitor chips to charge and balance the battery and power the rest of the system at the same time, or can I use only the balancer chip to do these things.

My battery pack is quite expensive ($120) and other people will be using it, so I need a solution that offers maximum safety for the batteries & users.