Battery Technical Info

5 Conclusion Based On 18650 Lithium Battery Pack Assemble Analysis



Normal 18650 lithium battery pack includes:18650 battery cell, battery protection board, connected nickel strip, lead-out nickel strip, green paper accessories, insulation paper, lead or plug wire, PVC packaging or shell, output (including connectors), key switches, electricity indication, and Eva, green paper accessories, plastic brackets, and other auxiliary materials together to assemble the battery pack.

Lithium Battery Pack Assemble

18650 lithium battery PACK process is mainly based on PACK battery structure to confirm. Most SmartPropel 18650 lithium battery pack process features are nearly the same, the characteristics are multi-series and multi-parallel 18650 lithium battery to accomplish the assemble. The biggest characteristic is flexible combinations. Most of the continuous orders can be achieved by semi-automation, we can imagine that 18650 lithium battery pack process is now more and more mature and simple. Take 48V 50Ah lithium Battery Pack for example.

1.What should 18650 lithium battery pack technology pay attention to when welding?

1) Welding current should be paid attention to when spot welding.
​2) The diameter of the welding pin should be paid attention to when welding 18650 lithium battery.
​3) The spacing of welding pins should be paid attention to when welding 18650 lithium battery.
4) The number of solder joints should be paid attention to when welding 18650 lithium battery.
​5.) Don’t make fire, short circuit, or dry joint.

2. What should 18650 lithium battery pack technology pay attention to when soldering?

1)18650 Lithium Battery solder should pay attention to wire diameter.
2)​18650 Lithium Battery Solder should pay attention to solder temperature constant stability.
3)When soldering tin, pay attention to how many seconds the soldering time cannot exceed.
4)Solder different 18650 lithium battery surface material will require different soldering iron head.

3.What should 18650 lithium battery pack pay attention when matching group?

1)Set the internal resistance, voltage, self-discharge.
​2)Set the channels and levels
​3)Set the number of pairings per channel ?
​4)Isolate and analyze when there’s defective products.

4.Multi-series and multi-parallel 18650 battery pack design craft skill

1)Take easy to operate priority principle, so that staff can handle easily.
2)Take safety operation priority principle, so that the staff operation is not easy to short circuit or have bettery preventive measures.
​3)Take equipment priority principle, use auxiliary equipment to complete as far as possible without manual labor, at least semi-automation
​4)Packaging design to be reasonable, easy to take easy to put. So that customer can fetch and install on the products conveniently.

5.18650 battery pack craft skill summary analysis

1)Apply high quality lithium cell. Qualified and stable suppliers provide good performance single cell, cell should passed a series of safety tests and performance tests. When they are qualified, then can be used .
​2)Require battery cell should be low internal resistance and good consistency, for 48V 50Ah lithium battery pack, must make sure low internal resistance to ensure high current discharge capacity, platform, heat dissipation, etc.
​​3)The battery structure adopts ventilation design, the space between two adjacent batteries is not less than 2mm, this structure requires to use plastic bracket to fixed battery.
​4) We use slotted nickel sheet for spot welding, the nickel sheet size meets the requirement of high current discharge, the nickel sheet material ensures low internal resistance, the spot welding machine guarantees stable work, the welding needle guarantees quality, the operator is trained and examined qualified to work, the spot welding spot is checked whether solid or not . Each batch of products must pass vibration test to verify the anti-vibration performance.
​​5) Different batches of batteries to make a typical finished product and do life tests to get the actual cycle life.
​​6)Verify battery performance at high and low temperatures. Assemble finished products and test the different discharge rate at high and low temperatures and get the actual discharge curve.


SmartPropel Original Work Writer:Nancy