Make 7.4V 2S Lithium Polymer Battery Pack

What is 7.4V 2S Lithium Polymer Battery Pack?

A 7.4V 2S lithium polymer battery pack is a lithium polymer battery configuration that consists of two lithium polymer cells connected in series. Each lithium polymer cell has a nominal voltage of 3.7V. When connected in series, the voltages of the two cells add up, resulting in a combined nominal voltage of 7.4V (3.7V + 3.7V).

7.4V 2S lithium polymer battery packs are widely used in various applications due to their high energy density, lightweight design, and ability to deliver a higher voltage compared to a single cell. Some common applications include radio-controlled (RC) devices, drones, portable electronics, and smaller electric vehicles.

How to make a 7.4V Lithium Polymer Battery Pack?

To make a 7.4V 2S lithium polymer battery pack, you will need two lithium polymer cells, a compatible connector, and a 2S balance connector. Please note that working with Lithium Polymer batteries can be dangerous if not handled correctly. Ensure you have the necessary knowledge, experience, and safety precautions in place before attempting to make 2s lithium polymer battery pack.

Here are the steps to make a 7.4V 2S lithium polymer battery pack:

1. Gather materials

  • Two lithium polymer cells, each with a nominal voltage of 3.7V
  • A connector compatible with your application (e.g., XT60, Deans, JST, etc.)
  • A 2S balance connector (usually a JST-XH connector)
  • High-quality, heat-resistant electrical tape or heat shrink tubing
  • Soldering iron and solder
  • Wire strippers, cutters, and other necessary tools

2. Prepare the Lithium Polymer cells

Ensure both cells have the same capacity and are in good condition.
Charge the cells to the same voltage level to avoid imbalances when connecting them in series.

3. Connect the cells in series

Solder the positive (+) terminal of one cell to the negative (-) terminal of the other cell.
Insulate the solder joint with electrical tape or heat shrink tubing to prevent short circuits.

4. Attach the main connector

Solder the main connector’s positive wire to the remaining positive (+) terminal of the connected cells.
Similarly, solder the main connector’s negative wire to the remaining negative (-) terminal of the connected cells.
Insulate both solder joints with electrical tape or heat shrink tubing.

5. Attach the 2S balance connector

Solder the balance connector’s ground wire (usually black) to the negative (-) terminal of the first cell (the same terminal connected to the main connector’s negative wire).
Solder the balance connector’s middle wire (usually blue or white) to the joint between the two Lithium Polymer cells (where the positive and negative terminals of the two cells are soldered together).
Solder the balance connector’s positive wire (usually red) to the positive (+) terminal of the second cell (the same terminal connected to the main connector’s positive wire).
Insulate all solder joints with electrical tape or heat shrink tubing.

6. Inspect and test the battery pack

Ensure all connections are secure and insulated.
Check the overall voltage of the battery pack using a multimeter or battery checker to confirm it’s 7.4V (nominal).
Test the balance connector by connecting it to a balance charger or cell checker to verify that both cell voltages are detected correctly.

7. Wrap and protect the battery pack

Use heat shrink tubing, electrical tape, or another suitable material to wrap and protect the entire battery pack, ensuring that all connections are insulated and secure.

How to order lithium polymer batteries?

1. Send your Requirements
Find us through the sidebar contact form, send us your requirements for the lithium polymer battery, such as dimensions(thickness x width x length), voltage, capacity, max working current, protection circuit module(PCM), wires request, thermistor(NTC), connector type, etc. We will recommend the best suitable rechargeable lithium polymer battery for you.
2. Quotation
When we receive your inquiries, we will reply to you within 12 hours. We mainly communicate by email.
3. Order Process
When you are ready to place lithium polymer battery orders with us, we will confirm the battery models, quantities, prices, and other details, and send you an invoice for payment. We accept PayPal payments, credit cards payment, and bank transfer payments. Then, we will arrange your order. The lead time depends on specific orders.
4. Shipment
When we finish the lithium polymer batteries, we will ship them via DHL/UPS/FedEx air shipping, it is safe and fast. And, we will send the tracking number to you when we get it.
5. Warranty
Our warranty for the lithium polymer battery is one year after the sale. (Refund or resend batteries)
Range of warranty: There is low voltage, expansion, or leakage with the correct use of the lithium polymer battery in the warranty period.

Popular 7.4V Lithium Polymer Battery Models

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