Connectors

Why Connectors?

Male and Female JST Connectors

Bunny of Team Malice has created a great connector guide.

Although some people may solder their batteries directly into their bots, nearly everyone uses connectors so they can unplug their batteries for easy charging. There are a lot of factors that go into deciding what the right connectors are for your application. All of the connectors mentioned below are suitable for Robot Combat but size, weight, current capacty and the physical security are all important to consider when deciding which one is right for you.

Terminology

Male and Female XT Connectors

• Male and Female connectors: Many connectors have a 'Male' connector type and a 'Female' connector type. There are a few reasons for this design approach. The connectors on the power-source side (battery) are typically 'Female' which means they receive the 'Male' connector which houses the electrical contacts inside the connector. This reduces the likelihood of the battery short circuiting by accident.
• Polarized: Many connectors are not symmetrical which means they will only plug into each other in one direction. This ensures that the positive and ground sides of the battery are not accidentally reversed.
• Crimped / Soldered: Wires need to be secured to the connector. This can be done physically with a crimp or by soldering the wire to the connector. In some connectors the wire can be both crimped and soldered.
• Anti-Spark: At higher voltages, electricity can arc across the connector. This damages the surface of the connector pins, which increases resistance and reduces their efficiency. Arc can even damage electronics. Some connectors are designed to reduce this effect. Although anti-sparking connectors can be more expensive, they are typically a better choice at high voltages.

Connector Types

Anderson Connector Sizes

• JST RCY: (Often called "JST", the name of the manufacturer.) These connectors are often seen on small Lipo batteries, and are frequently used in 150g or 1lb small robots. They often come with wires pre-attached for convenience. Instead of the smaller 22 gauge wire, look for ones that have at least 20 gauge wire, which will easily handle 5 amps. They have only a tiny latch to hold them together, so you might want to physically secure them with tape or a zip-tie.
• XT Connectors: This connector style is popular because of its fairly compact form factor and ability to handle high current. XT connectors come in 30, 60, and 90 amp versions but can handle more than their rated current for short periods of time. Additionally the XT connectors come in anti-spark versions which are especially useful in high voltage applications. Most XT connectors will require that you solder a wire to the connector. The connectors have a fair amount of thermal mass which can require a bit of practice with a quality soldering iron to make a good connection.
• Anderson PowerPoles: This older style connector is still very popular and comes in a range of physical sizes that are rated to handle between 15 and 350 amps. These connectors also have the advantage of a strong physical connection when plugged in. Although you can solder wires into these connectors, they are designed to be crimped.
• Bullet: These connectors come in various sizes to handle different current. They take up very little space, but their physical connection can be weak. Like other connectors, securing them with tape will help prevent power loss during a match.