Connector, Wire & PCM/BMS Customization

We start from your mating connector, board header, or an existing battery you want to match. If you can provide a part number, photo, drawing, or physical sample, we confirm pitch, pin count, polarity, keying, and mating force before building any sample. If only a device photo is available, we identify the most likely connector family and confirm it with you before proceeding.

Wire gauge selection should account for continuous current, peak current and pulse duration, wire length and the resulting conductor resistance, allowable voltage drop under load, temperature rise at the expected operating conditions, connector current rating, and available installation space. If device current or peak current increases from the original specification, the existing wire gauge should not automatically be assumed suitable — it should be recalculated and revalidated against the updated electrical and thermal requirements. Wire length is measured along the actual routing path from the cell tab to the connector inside the enclosure, because longer wire increases resistance and voltage drop under the same load.

A PCM (Protection Circuit Module) provides over-charge, over-discharge, over-current and short-circuit protection for single-cell and simple low-cell configurations. A BMS (Battery Management System) adds cell balancing and optional temperature monitoring or communication for multi-cell series packs. The choice depends on cell count, series-parallel structure, and whether the application requires active balancing. For 1S LiPo packs, a PCM is standard. For 2S and above, or 18650/21700 packs, a BMS is typically required.

Yes. Polarity, wire color, pin assignment, and exit direction are set to your specification. If you are replacing an existing battery, send the original or a clear photo showing pin orientation and wire colors. We reproduce the exact polarity and color scheme so the new pack is a direct drop-in replacement with no risk of reverse connection.

Protection thresholds are confirmed from the selected cell specification, charger, and real device load profile. Parameters include overcharge voltage, over-discharge cutoff, continuous overcurrent limit, short-circuit response time, and — for BMS — cell-balance start voltage. These values must match your actual load and charger behavior rather than using generic defaults, because a threshold that is too tight causes nuisance shutdowns and one that is too loose fails to protect the cell.

Yes. If the overcurrent threshold is set below the device startup surge or peak pulse current, the protection circuit will trip and cut power. This is one of the most common field issues with protected battery packs. During engineering review, we check pulse current requirements including startup current, pulse amplitude, pulse duration and repetition frequency to make sure the protection threshold has enough headroom for the real load profile without compromising cell safety.

Yes. Send the existing battery, a photo with dimensions, or a drawing showing connector type, pin count, wire gauge, wire length, color, polarity and exit direction. We reverse-engineer the interface and build a sample that matches the original connection. After you verify fit and function on a sample before mass production, we lock the specification for stable long-term supply.

An NTC thermistor may be required when the host device or charger needs real-time battery temperature feedback for charge control, thermal protection, or safety monitoring. The NTC can be wired in a 2-wire or 3-wire architecture, and these are not interchangeable — in some designs the NTC may share Battery− internally, while in others it uses a dedicated return conductor. The resistance value, B-constant, and connection topology must match what the host electronics expect. Temperature-based protection may be handled by the host system, the PCM or BMS, the charger, or a combination of these, depending on the overall system design. The correct approach should be confirmed during the custom battery project process before samples are built.