The formula for Power is Voltage x Current (W = V x A). To get more power (Watts) from a 3S system, you must significantly increase the current (Amps), which creates excessive heat and requires thicker, heavier wires. A 4S (14.8V) system achieves the same or greater power output by increasing voltage, keeping the current lower. This results in cooler operation, better efficiency, and allows for the massive torque needed by heavy-lift drones and professional saws.

A 4S pack consists of four lithium-ion cells in series. Since each cell has a maximum charge voltage of 4.2V, the entire pack must be charged with a dedicated charger outputting exactly 16.8V (4 x 4.2V).

To prevent irreversible damage to the cells, the Battery Management System (BMS) will typically engage its over-discharge protection and cut power when the total pack voltage drops to around 12.0V (which averages 3.0V per cell), or if any single cell in the series string drops to its minimum safe voltage.

“4S” means 4 cells in Series (determining the 14.8V). The “P” stands for Parallel. A 4S2P pack has 2 parallel strings (doubling the capacity); a 4S5P pack has 5 parallel strings (quintupling the capacity). A 4S5P pack contains 20 cells in total (4×5) and is designed for extremely long runtime or very high power delivery.

Yes, if designed correctly. In a 4S5P pack, the discharge current is shared across the 5 parallel cells. This means each individual cell experiences less stress, allowing the pack as a whole to safely deliver a massive continuous current, making it ideal for large robotics or heavy-duty tools.

Thermal management is a key part of our engineering. We select low internal resistance (low-IR) cells, use heavy-gauge pure nickel strips for connections, design proper physical spacing between cells where possible, and sometimes integrate thermal pads or heat sinks within the pack’s custom enclosure. The BMS also includes multiple temperature sensors to cut power if it gets too hot.

Absolutely. For applications like FPV racing drones or high-torque impact wrenches, we utilize specialized High-C 18650 cells capable of 20A or 30A continuous discharge, paired with a heavy-duty BMS to unleash maximum performance.

Due to the engineering complexity, custom BMS requirements, and safety testing involved with 4S packs, our Minimum Order Quantity (MOQ) typically starts around 10,000 units for professional and industrial applications.

It depends on the pack’s total energy capacity (Watt-hours or Wh). The strict FAA/IATA limit for carry-on is generally 100Wh (though up to 160Wh is sometimes allowed with airline approval). A 14.8V 6000mAh (4S2P) pack is roughly 88.8Wh, so it usually flies. A 14.8V 15000mAh (4S5P) pack is 222Wh and must be shipped as dangerous goods via cargo. We can design packs to meet specific airline limits.

To provide an accurate design and quote, our engineers need:

1. Target Capacity (mAh or Ah): How long must the device operate?

2. Continuous & Peak Discharge Current (Amps): The most critical factor for 4S; it determines cell choice and BMS rating.

3. Maximum Dimensions: The exact L x W x H of the battery compartment.

4. Application & Environment: E.g., a medical cart indoors or a drone outdoors (impacts thermal and durability design).

5. Wiring & Connectors: Required wire gauge (AWG), length, and high-current connector type (e.g., XT60, XT90, heavy-duty Molex).

6. Estimated Annual Volume.