Battery Protection for Rechargeable Coin/Button Cells

[with2ls]

I am working on a low power project that uses a rechargeable 3.7V lithium-ion coin/button cell (probably in the 2032 size range). Standard discharge current is <1mA with pulses up to 30mA. Standard change current is ~10mA.

Although it's highly unlikely over the lifetime of the product, the battery can be replaced by a professional. Can anyone give me some advice or point me to some app notes that discuss battery protection for rechargeable lithium-ion coin cells? The standard approach of using a battery protection IC to prevent OV, UV, and OC seems like overkill for low energy batteries like these (I also have very limited space). The battery charging circuit is set to 4.2V and contains some powerpath functionality, allowing it to cutoff the load at a low voltage (UV protection).

The following battery datasheet:

https://www.cde.com/resources/catalogs/RJD.pdf

even states:
Protection Circuit
Protection circuit can be provided upon request. However, protection circuit may be omitted for most applications without damaging performance and safety. Please consult our engineering staff for technical advice.

Any advice or guidance would be greatly appreciated. I would consider making the battery non-replaceable if it meant simplifying the battery protection circuit (if more is required).

 

[BradtheRad]

Since your post sounds as though you plan to be careful then you're probably aware there are risks to using Li-Ion cells. It's the type in news reports of rechargeable batteries causing fires and explosions.

Your data sheet link mentions their testing methods did not cause fire or explosion. However it makes one wonder whether they did experiments that DID cause fire or explosion! Reading between the lines I sense the data sheet giving us implied warnings about using Li-Ion cells.

I remember the first rechargeables on the consumer market were types able to tolerate a certain amount of abuse. Nicad, then NIMH. Evidently the push to miniaturization has encouraged manufacturers to give us a type that requires extra care (Li-ion). I'm not a Li-ion expert though I guess your description of your circuitry seems to include extra care.