Written by Logan F.
Quick answer: Choose by continuous current, not the number on the plug. Amass datasheets rate the XT30 at 15 A, XT60 at 30 A and XT90H at 45 A continuous; the name is the short-term peak. MT60 is a three-pole motor-to-ESC plug. Fit heat shrink before soldering and never expose both battery wires at once.
XT30, XT60, XT90 and MT60 connectors all do the same basic job: a keyed, gold-plated plug that carries high current between a battery, a speed controller (ESC), a charger or a motor. They differ in size, current capacity and pole count, and the numbers in their names are easy to misread. This guide covers what those numbers mean, which connector suits which job, what wire to pair with each one, and how to solder them safely. All four are in our RC electrical connectors range.
What the number in the name means
Amass, the manufacturer behind the XT and MT connector families, publishes two current figures for each connector. The lower one is the rated (continuous) current. The higher one is the instantaneous current, and that is the figure in the name: an XT60 is rated for 30 A continuous and 60 A instantaneous in the Amass XT60 datasheet.
Holybro's connector guide, which quotes Amass ratings, describes the continuous figure as a four-hour test with a temperature rise below 60°C and the burst figure as a one-minute test to the same temperature limit. In practice that means you size the connector for the current your system draws for minutes at a time, and treat the name figure as headroom for short punches of throttle.
Our XT30, XT60 and XT90 listings state both figures: the peak rating that gives the connector its name, and the continuous rating Amass publishes. When you plan a build, size the connector on the continuous figure in the table below and on the continuous current your ESC or load actually draws.
Connector comparison
| Connector | Poles | Continuous (Amass datasheet) | Short-term | Amass recommended wire | Typical use |
|---|---|---|---|---|---|
| XT30 | 2 | 15 A | 30 A | 18 AWG | Small drones, compact packs, low-current accessories |
| XT60 | 2 | 30 A | 60 A | 12 AWG | Mid-size RC and drone batteries, ESCs and chargers |
| XT90 (XT90H) | 2 | 45 A | 90 A | 10 AWG | Large packs, UAVs, robotics and high-power charging |
| MT60 | 3 | 30 A | 60 A | 12 AWG | Brushless motor to ESC (three phases in one plug) |
Figures are from the Amass XT60, XT90H and MT60 specification sheets, and from the XT30U ratings published by distributors TME and Electrokit. TME lists several XT90 parts at 40 A, and lists the Amass MT60 at 30 A, so check the datasheet for the exact part you buy.
Matching wire gauge to the connector
The recommended wire in the table is the gauge Amass pairs with each connector. Thinner wire has more resistance and heats up sooner, so it becomes the weak point of the circuit. Here is how the common RC gauges compare, using the standard American Wire Gauge sizes listed on Wikipedia's AWG table.
| AWG | Conductor diameter | Cross-section | Where you will see it |
|---|---|---|---|
| 10 | 2.588 mm | 5.26 mm² | Amass recommendation for XT90H |
| 12 | 2.053 mm | 3.31 mm² | Amass recommendation for XT60 and MT60 |
| 14 | 1.628 mm | 2.08 mm² | Our pre-soldered XT60 leads (15 cm, silicone insulated) |
| 16 | 1.291 mm | 1.31 mm² | Between the XT30 and XT60 recommendations |
| 18 | 1.024 mm | 0.823 mm² | Amass recommendation for XT30 |
Our pre-soldered XT60 leads use 14 AWG, high strand count silicone wire, which keeps short leads flexible and easy to route. If your continuous draw is close to the XT60's 30 A datasheet rating, step up to 12 AWG as Amass specifies, and keep leads short.
How to choose between XT30, XT60 and XT90
- Find the continuous current. Use the continuous rating of your ESC or the measured draw of your load. A battery's C rating only tells you what the pack can deliver, not what your model pulls.
- Pick the connector whose continuous rating sits above that number. Short bursts up to the name figure are what the instantaneous rating is for.
- Match what you already own. If your charger lead and existing packs are XT60, staying with XT60 avoids adapters, which add extra joints to every connection.
- Consider size and weight. On a small quad the XT30's compact housing matters. On a large ground vehicle or robot, the XT90's larger contacts are worth the bulk.
Where MT60 fits
The MT60 is not a battery connector. It combines three 3.5 mm gold-plated bullet terminals in one keyed housing, so a brushless motor plugs into its ESC in one step instead of three separate bullets. That makes motor swaps tidy, and our MT60 pairs include protective end caps for a neat finish. One trade-off: with loose bullets you can reverse a motor by swapping any two wires at the plug. The MT60 housing only fits one way, so reverse the motor in your ESC settings if the firmware supports it, or swap two motor wires before you solder.
Which half goes on the battery?
The Amass XT60 and XT90H datasheets list the female connector for the battery and the male connector for the controller or charger. The usual reasoning is that the socket contacts sit inside the housing, so the side that is always live is harder to short against a tool or a loose wire. Follow the same convention across all your packs so everything mates.
How to solder an XT60 (the same steps suit XT30 and XT90)
XT and MT60 connectors use solder cups, not crimp terminals, so you need a soldering iron rather than a crimper. Use a temperature-controlled iron with a large chisel tip, rosin-core solder, wire strippers such as the Iwiss FSA-0626/B, heat shrink and a clamp or vice.
- Slide heat shrink on first. Cut one piece per wire, long enough to cover the solder cup and a few millimetres of insulation, and push it well back from the joint.
- Strip and tin the wire. Strip just enough to sit fully in the cup, twist the strands and flow a thin coat of solder through them.
- Hold the contacts in line. Plug the connector into a spare, unwired mating connector and clamp it. The spare keeps the contacts aligned while the nylon housing is warm.
- Fill the cup. Heat the cup and melt in solder until it is about three-quarters full.
- Join the wire. Reheat the cup, push the tinned wire in and hold it still until the solder sets. A good joint is smooth and fully wetted, with the insulation close to the cup.
- Work quickly. Amass lists an operating temperature range up to 120°C for these connectors. Long dwell times soften the nylon and can let a contact shift so the plug no longer mates.
- Insulate. Once cool, slide the heat shrink up against the housing and shrink it.
- Test before use. Check with a multimeter that there is no continuity between the two contacts and that red goes to the positive contact.
Polarity: red is positive, black is negative. Check the housing for moulded + and − marks, then hold the new connector beside a correctly wired lead from your charger or an existing pack and match it contact for contact before you solder. Reversed polarity can damage an ESC, charger or battery.
Safety: soldering and LiPo connectors
Soldering
- Rosin flux fume irritates the eyes, nose and throat, and repeated exposure is linked to asthma and dermatitis according to WorkSafe WA's guidance on soldering with rosin fluxes. Use a fume extractor or strong ventilation and keep your face out of the plume.
- Wash your hands after handling solder, especially leaded solder, and do not eat at the bench.
- Park the iron in its stand between joints. Freshly soldered contacts stay hot for a while.
Working on LiPo batteries
- Replace a battery connector one wire at a time: cut one lead, solder and insulate it, then cut the second. Two bare battery leads touching is a dead short.
- Take off rings, watches and metal bracelets before working near a pack.
- Work on a non-flammable surface. The ACCC's lithium-ion batteries guide recommends charging on surfaces such as concrete, ceramic or steel, monitoring charging, and never charging on beds, sofas or carpet.
- Do not use or rework a pack that is dented, swollen, leaking, venting or overheating. Put damaged batteries in a fireproof container and take them to a council depot or transfer station, never household rubbish.
- Replace connectors that are loose, discoloured or melted rather than reusing them.
Shop the materials in this guide
- RC Electrical Connectors: XT30, XT60 and XT90 connectors as singles and male and female pairs
- XT60 Power Connector Pair with Pre-Soldered Leads: 14 AWG silicone leads already fitted for quick repairs
- XT90 High Current Connector Pair: for large packs and high-power charging
- MT60 Connectors: three-pole 3.5 mm plugs for motor-to-ESC connections
- Iwiss FSA-0626/B Wire Stripper: clean strips on AWG 22–10 or AWG 30–20 wire
- Electronics and Wiring: strippers, crimpers and connectors in one place
Frequently asked questions
Can I run 60 A continuously through an XT60?
Not according to the Amass datasheet. It rates the XT60 at 30 A continuous and 60 A instantaneous. Plan for 30 A or less of sustained current and treat 60 A as a short-term limit.
Do I need a crimping tool for XT or MT60 connectors?
No. They have solder cups, so a soldering iron is the right tool. Crimpers are for crimp terminals such as open barrel, Deutsch or battery lugs, which our Iwiss crimping tools cover.
What wire gauge should I use with XT60?
Amass rates the XT60 with 12 AWG. Shorter 14 AWG leads, like the ones on our pre-soldered connectors, are common where the continuous current is well under the rating.
Why does my connector get warm?
Common causes are current above the continuous rating, wire that is too thin, a poor solder joint, or worn contacts that no longer grip. Amass lists a mechanical life of about 1,000 mating cycles, so replace heavily used connectors.
Can I mix XT30 and XT60 gear with an adapter?
You can, but every adapter adds two more joints, and the whole path is limited to the smallest connector's rating. Standardising on one connector type is simpler.
