Rechargeable 3.7V Li Lipo Lithium Polymer Ion Battery Pack with 2 Pin 2.0mm/1.25mm JST Connector (503035 500mAh 2.0Jst)

Great seller

Check your polarity before plugging in! Like an idiot, I just assumed the polarity was the same all around, and matched the Adafruit battery picture. The JST connector only plugs in one way (ridge facing the sky). I was wrong. Didn't notice polarity was flipped with this battery I ordered off Amazon. Plugged my ESP32 feather with USB, then plugged in Amazon battery. Feather started smoking and burnt out. It's done.So, in conclusion kids, never assume! Check your polarity before plugging stuff in not directly from the microcontroller manufacturer!

Works

Horrible battery. The first time I plugged it in, there was no response on my microcontroller and when I tried a different battery, it still didn’t work. I switched the MC and uses the different battery and it worked. I ordered the same battery again assuming it was defective and when I plugged it in to the new microcontroller, smoke immediately started coming off the microcontroller. I used a USB to check the MC and it doesn’t work anymore. Batteries are not recommended.

Connector didn’t fit.

Product fits perfectly in the area which held the previous battery plus it has a larger capacity.

Perfect replacement battery for my speaker.