Low Cost Individual Cell Monitoring?

Has anybody ever come up with a low cost method for monitoring individual cells in a pack. I've looked at several techniques, but most would cost several times the cost of the cells. Ideally I'd be looking for temperature, voltage, and current (in\out)

Anybody any thoughts?

It's hard for sure to do it very cheap. Are you looking at cheaper than per 1 cell or per 1 pack?

Tiny MCU per cell is cheap and can monitor. Then you need to transfer the data and you need to isolate that transfer and cost a tiny bit more.

For packs you can do wirelss and ESP8266/32 is good choice that do Wifi.

I do like my home automation and monitoring, to the extent that there are over 50 WiFi connected devices in the house, most of which are 8266 based in someway. So I'm used to programming Arduino style devices and aggregating data etc. The tiny MCU is definitely amongst the cheapest but when you add something like an acu712 plus a thermometer, prices start to mount significantly. Which I guess is inevitable.

I find it a little disappointing that none of the 18650 battery shields I've seen have appropriate sensors built in.