Sourcing from potential vendors, we find not many offer battery with protection circuit. We ordered from a particular vendor 20 pieces of button-top higher-priced battery with protection circuit to check battery performance consistency. It was a bit of a surprise seeing the batteries were nicely packaged, each with its plastic wrapper and box, 3 pieces packaged into a larger box.
One with battery protection circuit should first measured 0V, due to battery output being cut off by the protection circuit to avoid battery discharging below certain threshold voltage, say 2.9V for example. After charging it for couple seconds, the battery should measure voltage around the cut-off threshold, not near zero voltage.
Complaining to the battery vendor, they agreed to resend the correct batteries.
Later received correct batteries, they are a bit larger in length due to the extra protection circuit at the bottom. After discharging for 24 hours, it first measured 0V, and measured 2.9V after charging for 3 seconds, showing correct behavior of one having battery protection circuitry.
Curious to know what integrated circuit is used for battery protection, we teared down a battery to have a look. It uses DW01 battery protection IC to protect battery from overcharge, over-discharge, or over current; and use 8205A MOSFET as electronic switch for battery protection. This seems to be a commonly seen battery protection configuration, also described in this article.
Initial order for the 20 piece battery was placed on May 13. It took over 2 months to sort out issues, receiving correct batteries, and getting it verified till this week! How slow things could get when there is lead time, delivery time, and mistakes involved !
We checked various $300 ~ $350 3-axis GoPro and smartphone gimbals that we bought for testing which also uses 18350 battery, much to our surprise their rechargeable batteries are all without battery protection circuitry. Very strange.