OEM 12v 400ah Lithium Battery For Trolling Motor

Support the production process of OEM12V lithium batteries: the entire process chain from battery cells to finished products

1. Battery cell preparation and selection
Cell type: A 12V lithium battery is typically composed of 3 to 4 3.7V lithium-ion cells (such as 18650, 21700 cylindrical cells, or pouch, square aluminum shell cells) connected in series (3.7V×3≈11.1V, 3.7V×4≈14.8V, and requires a BMS to reduce the voltage to 12V).
Core technology:
Electrode sheet production: The positive and negative electrode materials (positive electrode: lithium iron phosphate/ternary material + conductive agent + binder; The negative electrode (graphite) is coated on aluminum/copper foil, dried and then cut.
Cell assembly: The positive and negative electrode sheets are combined with the separator (which isolates the positive and negative electrodes to prevent short circuits) by winding (cylindrical/pouch) or laminating (square) methods, the electrolyte is injected, and the casing is sealed.
Activation and capacity separation: Activate the cells during the first charge and discharge. Screen and match the cells based on capacity, voltage and internal resistance to ensure consistency in series groups (inconsistency will lead to overcharging and overdischarging, affecting the lifespan).

2. Battery pack integration
Circuit design
BMS (Battery Management System) : It must integrate overcharge/overdischarge/overcurrent/short-circuit protection, balance the cell voltage (the voltage difference of series cells ≤50mV), and some BMS support temperature monitoring (operating temperature -20 ℃ to 60℃, heat dissipation/heating is required if exceeded).
Wiring layout: The series wires of the battery cells should use wires of appropriate cross-sectional area (for example, in a 160AH high current scenario, the cross-sectional area of the wire should be ≥10mm² to reduce internal resistance and heat generation), and the solder joints need to be tin-plated to prevent oxidation.
Enclosure and Protection:
Sheet metal shell processing: Cold-rolled steel plates are formed by stamping, with insulating barley paper pasted on the inner wall. Heat dissipation holes and installation holes are reserved, and the surface is sprayed with anti-corrosion coating (such as epoxy resin). The waterproof grade can reach IP54 (splash-proof).

3. Testing and Quality Inspection
Performance testing: Charge and discharge cycle testing (≥500 cycles under standard working conditions, capacity retention rate ≥80%), high and low temperature testing (discharge capacity ≥70% at -20℃, charging efficiency ≥90% at 60℃).
Safety tests: Short-circuit test (simulating whether the BMS cuts off the circuit within 10ms when the wire is short-circuited), compression test (no fire or explosion under 1000N pressure), drop test (no cracking of the shell when dropped from a height of 1.5m).

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