Rechargeable Lithium-ion Battery Pack

Building a lithium ion battery pack begins by satisfying voltage and runtime requirements, and then taking loading, environmental, size and weight limitations into account. Portable designs for consumer products want a slim profile and the choice is a prismatic or pouch cell. If space allows, a cylindrical cell such as the 18650 often provides the lowest cost and best performance in terms of specific energy, safety and durability.

Most battery packs for medical devices, power tools, e-bikes and even powertrains for electric cars (EV) are based on the 18650. This appears impractical but the small cell works well because it is one of the most mature Li-ion formats available, is produced in high volume and enjoys a low cost per Wh.

The cylindrical cell is not ideal as it leaves empty spaces in a multi-cell configuration. This disadvantage turns into an advantage when considering flexibility and cooling. The Tesla S85 EV uses over 7,000 cells, switched in parallel to boost the current and in series to increase the voltage. Should one cell in series open, the total power loss is minimal; if one in parallel shorts, fuse protection removes this cell from the circuit. Failing cells can thus be eliminated without bringing the battery down.

A&S Power is a lithium battery manufacturer in China over 10 years, our main products include li polymer battery, lifepo4 battery, li ion battery cell and 18650 battery pack. For the application of outdoor audio, POS terminal, medical devices, power tools, solar street light, security products etc., 18650 lithium ion battery will be your best choice.