XT-60.. JST.. EC-5.. and who the heck was bullet? Electrical Connectors used in Lithium battery may be very confusing for beginner and sometimes even for us who have been in the industry longer time. Let's take a quick look for most commonly used connectors in the li-ion battery world and figure out what they are used for!
What is an electrical connector?
An electrical connector is an electromechanical device used to create an electrical connection between parts of an electrical circuit, or between different electrical circuits, thereby joining them into a larger circuit. Most electrical connectors have a gender – i.e. the male component, called a plug, connects to the female component, or socket.
JST Balancer Cable Connectors
JST connectors are a type of electrical connector manufactured according to the design standards originally developed by J.S.T. Mfg. Co. (Japan Solderless Terminal). JST offers numerous series (families) and pitches (pin-to-pin distance) of connectors.
The term "JST" is frequently misused as a colloquial expression referring to any compact white electrical connector that is mounted on printed circuit boards (PCBs). Some individuals mistakenly associate this term with all small white connectors, regardless of their brand or type, which can lead to confusion and miscommunication within the electronics industry.
To avoid any misunderstandings, it is recommended to identify a connector by including the manufacturer's name, specific connector series, and if necessary, the pitch. Examples of clear identification include "JST-XH," "JST-XH-2.50mm," or "2.50mm JST XH-series" or other similar variations.
Ampacity: Up to 15 amps (general range).
Applications: Low-current applications, batteries for small electronic devices.
Pros: Reliable and easy to use. Although it fits tightly, it does not lock and can be easily removed.
Cons: It is not recommended for use with high currents and it does not have a locking mechanism.
EC Series Connectors: EC3/EC5/EC8
EC3, EC5, and EC8 connectors are types of power connectors that are extensively used in high-current applications, particularly within the remote-controlled (RC) hobby industry. These connectors are well-known for their capacity to handle high current loads and deliver a secure and efficient electrical connection.
Ampacity: Up to 60 amps (EC3), up to 120 amps (EC5), up to 240 amps (EC8).
Applications: RC vehicles, high-current devices
Cable used: EC3: 14-12 AWG; EC5: 12-10 AWG; EC8: 10-8 AWG (The EC8 Male connector is compatible with wires of up to 8 AWG);
Pros: Able to withstand strong currents. Extremely easy to solder (but remember the polarity!). Heat shrink tubing is not necessary.
Cons: Bulky compared to XT-connectors and not as sturdy in construction.
XT series connectors
XT-connectors boast a modern design and offer numerous benefits for daily use in remote control devices compared to older T-plug models. Their bullet-shaped terminals are round, spring-loaded, and coated in gold for enhanced conductivity, all while being firmly encased in a durable, heat-resistant nylon housing that prevents separation. These connectors are designed for one-way connection only and are easily identifiable with their distinguished yellow or black color. In short, XT-connectors are the perfect match for your RC needs.
Ampacity: XT-30: 15A/30A (recommended); XT-60: 30A/60A (recommended); XT-90: 60A/90A (recommended); XT-90: 120A/150A (recommended);
Cable used: XT-30: 16-18 AWG; XT-60: 14-12 AWG; XT-90: 12-10 AWG; XT-150: 8 AWG;
Rated Voltage: 500V DC.
Plug Type: XT-90: 5mm bullet; XT-150: 6mm bullet;
Pros: Cannot be connected wrong way. Easy and safe to use. Good grip and very strong connector body. Pretty easy to solder (watch out for high temp or the plastic body may melt!)
Cons: Larger size makes things tight sometimes. Requires heat shrinks.
Bullet or banana plug
The banana plug is named after its slightly bulging shape like a banana. The bullet plug is named after its straight shape resembling a bullet. Those are variations of the same thing. But a 4mm is a 4mm and both fit into a 4mm socket.
Ampacity: 2mm Bullet: 25 A; 3.5mm Bullet: 50 A; 4mm Bullet: 90 A; 5mm Bullet: 120 A; 5.5mm Bullet: 130 A; 6.0mm Bullet: 150 A; 6.5mm Bullet: 160 A; 8.0mm Bullet: 200 A.
Cable used: 2mm Bullet: 20 AWG; 3.5mm Bullet: 16 AWG; 4mm Bullet: 14 AWG; 5mm Bullet: 12 AWG; 5.5mm Bullet: 12 AWG; 6.0mm Bullet: 10 AWG; 6.5mm Bullet: 10-8 AWG; 8.0mm Bullet: 8 AWG.
Pros: Affordable and long-lasting. Offers speedy and effortless use for those familiar with the process. Fast and efficient for soldering.
Cons: High risk of short circuiting. Prone to incorrect connections. Poses a fire hazard.
In conclusion, the above highlights the commonly used connectors, however, the market offers a diverse range of lithium battery wire connectors. When deciding on the appropriate connector, it is crucial to assess various factors such as the device's current and power demands, connector structure, and unique features.
