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Polymer Lithium Ion Battery (3.7V, 400mAh)

Slim, extremely light-weight batteries based on Polymer Lithium (LiPo) Ion chemistry. Battery output 3.7V (nominal), capacity 400mAh.

Availability: In Stock.

2209 £3.30
(£3.96 incl VAT)

These 3.7V Polymer Lithium Ion (LiPo) batteries provide a high power capacity in a very small lightweight package, making them ideal for many applications. They are often used in portable consumer products such as Bluetooth speakers and mobile phones.

The batteries are supplied with 100mm leads terminated with a standard 2 pin JST connector.

These Polymer Lithium batteries come with a built in protection circuit which protects against; over voltage, over current, over discharge and also provides short circuit protection. When fully charged the battery will have a voltage of around 4.2V and when fully discharged the battery has a cut off voltage of 2.4V.

These batteries do not have a hard protective case. You should take care when housing the batteries in your design to ensure they have sufficient mechanical protection to protect the battery from any possible damage. If a battery does become damaged (dented, bent, etc) then it should not be used.

Lithium Polymer batteries require special charging circuits. Do not attempt to charge these with anything but a specialised Lithium Polymer charger.

Though these cells are rated for discharge rates of up to 2A, due to the connecting wire and connector used we do not recommend exceeding a discharge rate of more than 1A.


  • Built in protection circuit to prevent over charging or discharging.
  • Built in short circuit protection circuit.
  • Robust power source under extreme conditions (-10 to 60C).
  • JST connector.
  • Maximum discharge rate of 2A, however we do not recommend exceeding 1A.


  • 1 x Polymer Lithium Ion Battery - 400mAh.


  • Maximum Length: 35mm.
  • Maximum Width: 23mm.
  • Maximum Height: 5.2mm.
  • Cable Length: 104mm.




  • These batteries are capable of delivery a high current output. If using conductive thread, a short in the circuit (between thread) could create sparks and heat. We recommend using coin cell holders and batteries for wearable projects.
  • When removing the JST connector from a socket do not pull it out using the connecting wires as this can damage the connector.
  • Neither the battery or its protection circuit are water proof, and if being used in an environment where water contact is possible or likely then the battery should be further protected.


  • Due to shipping restrictions we are only able to ship a maximum of eight of these batteries to locations outside the UK. If more than eight are added to the cart eight will be shipped and the difference credited to your card. There is no limit on UK orders which are sent by road.
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