Battery protection IC for LIP2032

I’m designing my first circuit where I need a Li+ power source. Due to size restrictions I want to use a LIP2032 coin cell battery.

I understand that when using Li+ batteries I should include a battery protection circuit to cover overdischarge and short circuit issues. I’m looking for a discreet IC (smd package) that does not require a lot of external components.

I do not plan to include battery charging capabilities. If it is a consideration this battery/circuitry is separate from the main board. It plugs into the main board via jst power connector.

Thanks for any help.

The small primary (non-rechargeable) lithium coin cells such as the common 2032 size have a relatively high internal impedance and relatively low energy capacity, and as such they’re commonly used without auxiliary protection circuits. The secondary (rechargeable) lithium cells such as the pouch types and the ubiquitous 18650 cells are where protective circuits become a must-have.

@rick_1976 Thanks, that is what I read. I’ll be using the secondary (rechargeable) 3.7v 2032.

@Moebiusfan Not including a recharge capability in the powered device would suggest a remove-to-recharge sort of model, in which case some sort of under-voltage lockout mechanism in the powered device would be appropriate to guard against cell damage due to over-discharge. Products such as the BQ2970x allow a person to cover the bases of Li(x) cell protection without too much hassle. Other products of similar kind are also catalogued under the PMIC-Battery Management family, with varied functions, features, etc. Whatever you’re powering with it may have some sort of UVLO function available that could get the job done, or a reset/supervisor type of device might be used to build the needed function also. There’s more than one way…

If you’re not planning to recharge at all though, using primary 2032 cells instead may be preferable, since they cost upwards of 10x less and store twice the energy.

@rick_1976 Thank you for the information; that should get me on the right track. I chose not to include a charging capability to provide the most flexible solution to the user. There is no way to determine which orientation the user will install the PCB, so reaching the USB connector might become impossible. It would simplify things for the user to simply remove the battery for recharging.

I don’t have UVLO capabilities designed into the Main PCB circuit. The design is modular and allows the user to select a range of battery PCBs from 1-cell up to 4-cells. So I do need to include a UVLO circuit as well as a constant current circuit that allows for between 3.7 -15 volts of power.

Thanks - I have some research to do now.