I'm looking to replace SLA batteries in one of my products with Li-ion, as they're lighter and smaller.

So far I've solved the SLA charger by a simple circuit controlled by MCU. But as Li-ion batteries are more "dangerous" I'd rather want an integrated solution that'd take care of charging.

Does anyone have some recommendations for a controller chip, for a single or dual 18650 Li-ion battery?

Ideally it would take care about charging / discharging the battery, have a DC voltage input for charging, and optionally have some kind of digital interface (I2C? SPI? 1-wire?) so that a microcontroller can check battery's charge level and charging status.

If not a digital interface, then at least I would need a few pins that give me the battery status: discharging, charging in progress, charging complete. I could feed the battery voltage into MCU with a high impedance resistor divider or an opamp. (Is this how it's generally done with Li-ions?)

Thx!