Technical update: September 14, 2026. This page retains Radical RC’s original connector and wire chart as a historical, unverified reference; confirm the exact part before use.
Quick answer: Identify an RC connector by its molded name or part number, keying, contact layout, and the equipment maker’s drawing. Confirm polarity from the battery, ESC, receiver, or servo manual and verify it before applying power. Choose wire by its actual AWG, current, total circuit length, insulation, temperature, and termination. The chart below is a practical Radical RC reference for common connector names and wire sizes; its amp values are not universal ratings for every connector that looks the same.
How to identify an RC connector and polarity
Start with the markings on the housing. Look for a family name, part number, molded polarity marks, keying features, the number of contacts, and the contact or pin size. “JST/BEC,” “Tamiya,” “Deans,” “EC,” “XT,” and “bullet” are useful family or trade names, but they do not identify one exact manufacturer part. Two plugs can share a color or general shape while using different contacts, wire sizes, ratings, or pin assignments.
- Remove all cells and battery packs before inspecting or tracing wires.
- Compare the housing and contacts with the connector manufacturer’s drawing. Match the exact series and suffix, including board, signal, high-current, keyed, or sealed versions.
- Trace each conductor to its destination. For a battery or ESC lead, confirm positive and negative from the equipment documentation. For a receiver or servo lead, confirm the signal, positive, and negative positions from the receiver or servo manual. A common three-wire servo lead pattern is not a guarantee of pin order or voltage compatibility.
- With all cells and battery packs disconnected and the circuit fully unpowered, use a continuity check when you need to trace a wire. Do not rely on red and black insulation, housing color, or a plug that happens to fit. If polarity or voltage is uncertain, stop and identify the part before connecting a pack.
Mechanical fit only tells you that two housings can enter each other. It does not prove compatible polarity, voltage, contact spacing, current capacity, or safe use. Never force a keyed connector or assume that an unmarked replacement has the same pinout as the connector it resembles.
Why connector amp ratings are not universal
A current rating belongs to an identified connector, contact, wire, termination, and test condition. It varies with wire size and construction, total length, temperature, contact material, energized positions, and termination quality.
Manufacturer sources show why: Molex’s Micro-Fit overview lists up to 10.5A for its named family with 30–18 AWG; the related Molex specification describes a 30°C temperature-rise test and derating factors; TE Connectivity lists application variables; and the AMASS XT60-F page lists 35A with 12AWG for that named part. These figures are tied to their stated family, part, wire, and test conditions; they do not update the historical chart or rate generic lookalikes.
RC connector current reference
The table retains Radical RC’s original reference values for common RC connector names. “Continuous amps” is the value shown in that legacy chart, and “chart wire GA” records the original wire-gauge reference. Confirm the exact part and its data sheet before using any value for a safety or design decision. A dash means the original chart did not provide a value; no value has been inferred.
RC wire gauge chart
AWG means American Wire Gauge. The smaller the AWG number, the thicker the conductor: 10 AWG is larger than 16 AWG, and 16 AWG is larger than 22 AWG. Thicker wire usually has less resistance, but a wire’s safe current depends on its insulation, strand construction, temperature, installation, length, and termination. Voltage drop also increases with current and the total path length of both the positive and return wires. That matters in low-voltage receiver systems, where a small drop can reduce the available margin even when the wire is not visibly hot.
This second table preserves the original wire data. The “chart amps” column is a reference value from the original page, not a universal ampacity table. Do not fill in the dashes by guessing or apply a listed value to a different wire product.
Receiver and servo connectors versus motor power connectors
Receiver and servo leads usually combine a signal conductor with low-voltage power and ground. They belong to the receiver/servo wiring system and must follow that equipment’s pinout and voltage limits. An ESC or motor battery lead carries substantially different power and should be selected using the motor system’s expected current, the connector’s exact data sheet, the wire run, and the termination. A receiver plug that fits a socket is not automatically suitable for a motor battery, and a motor connector is not automatically suitable for a receiver.
If you are choosing between 4.8V and 6V receiver packs, read Radical RC’s 4.8 Volt or 6 Volt guide and check the receiver and servo specifications. For charging, pack condition, and general battery questions, see the RC Battery FAQ. When replacing a connector, follow the exact connector maker’s crimp or solder instructions and inspect the finished termination before use.
Shop connectors and wire
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