Details
A tiny rechargeable 3.7V lithium polymer battery, pre-fitted with a JST PH 2.0mm 2-pin connector. At just 3 grams and 3 mm thin, it is light enough to sit on a wearable without bulk.
- Voltage: 3.7V nominal (4.2V fully charged)
- Capacity: 110mAh
- Model: 302025
- Size: about 25 mm tall x 19 mm wide x 3 mm thick
- Weight: 3.0 g
- Connector: JST PH 2.0mm, 2-pin (optional: you can cut it off and use the bare wires)
How long will it run?
As a guide, for a strip of 10 WS2812B (NeoPixel) LEDs driven by a small ESP32 dev board (roughly 80mA while running):
- Gentle animations at low brightness: about 30 to 40 minutes
- Bright colour effects: about 15 to 20 minutes
- All 10 LEDs at full white: about 10 minutes
These are estimates. Real run time depends on your board, brightness and effects. For longer wearable use, keep brightness low or choose a larger battery.
Charging it
Pair it with our Lithium Battery Charging Board, a tiny USB-C charger with built-in protection that is small enough to sew into a garment. The board takes soldered battery wires, so cut off the JST connector and solder the red and black wires to it.
Safety and shipping
- Check polarity before plugging in or cutting anything. JST connectors from different suppliers can be wired the opposite way round, so confirm which wire is positive with a multimeter.
- If you cut the connector off, cut one wire at a time and cover each end straight away so they cannot touch and short.
- Do not puncture, crush or short the battery.
- Limit of 3 batteries per order in total, due to postal regulations for lithium batteries. Each is securely wrapped for shipping.


