Lithium Polymer Battery Connectors Explained Simply

Mari Chen

Hello everyone, I am Mari Chen, a content creator who has been deeply involved in the lithium battery industry and the chief content officer of yungbang . Here, I will take you through the technical fog of lithium batteries - from material innovation in the laboratory to battery selection on the consumer side; from cutting-edge battery research and development to safety guidelines for daily use. I want to be the "most knowledgeable translator" between you and the world of lithium batteries.

Lithium Polymer Battery Connectors

When you use lithium polymer batteries, you work with two main types of connectors: main connectors and balance connectors. Each type has a special job. Understanding these battery terminal connectors helps you get the best performance, safety, and reliability from your lipo batteries.

Main Connectors

Main connectors, also called discharge connectors, are the primary battery terminals that deliver power from your lithium polymer battery to your device. These terminals handle high current and must support strong electrical performance. You find main connectors on lipo batteries used in drones, RC cars, and other electronics.

Main connectors come in different shapes and sizes. Some popular types include XT60, XT90, EC5, and Deans. These battery terminal connectors are designed to handle different current ratings. For example, an XT60 terminal can handle up to 65A, while an EC5 terminal can handle up to 120A. The right terminal ensures your device gets enough power without overheating or causing damage.

Tip: Always match the current rating of your battery terminals to your device’s needs. Using high-quality connectors improves reliability and keeps your lipo battery safe.

Here is a table to help you understand the main types of battery terminal connectors and their uses:

Connector Type	Definition	Current Rating	Advantages	Typical Applications
Discharge (Main Power) Connector	Handles device power supply, designed for current requirements	Varies (e.g., XT30: 30-40A, XT60: 65A, EC5: 120A)	Designed for high current, secure connection	Drones, RC vehicles, electronics
XT60	Nylon connector, up to 65A	65A+	Strong, avoids melting, easy to plug/unplug	Drones, RC cars, robotics electronics
XT90	Larger version of XT60, up to 90A	90A	Handles higher power, sturdy connection	Large drones, RC trucks, high power devices
EC5	5mm bullet pins, up to 120A continuous	120A continuous, 150A burst	Easy soldering, high current rating	Large electric planes, RC cars
Deans	Compact, secure connection	Moderate to high current	Compact design, secure	Hobby and RC applications

You use these battery terminals to connect your lipo battery to your device or lipo battery charger. The main connector must fit tightly to prevent loose connections, which can cause heat and reduce performance. Good lithium battery terminals also help prevent reverse polarity, which protects your electronics.

Balance Connectors

Balance connectors are smaller battery terminal connectors with several wires. You find these terminals on every lithium polymer battery pack. Their main job is to help with charging lipo batteries safely and evenly. Each wire in the balance connector connects to a single cell inside the battery. This setup allows your lipo battery charger to check the voltage of each cell.

When you charge your lipo batteries, the balance connector lets the charger monitor and balance the voltage across all cells. This process keeps every cell at the same voltage, which extends battery life and improves safety. If one cell charges faster than the others, the charger uses the balance connector to slow it down and let the others catch up.

Here is a quick look at how balance connectors work:

Each balance connector has one wire for each cell, plus one extra wire.
The most common balance connector is the JST-HXT, but some manufacturers use different plugs.
The wires in the balance connector are thinner than the main terminals, but they still connect directly to the battery cells.
Always check the wiring and polarity before making connections to avoid mistakes.

Connector Type	Role in Power Delivery and Charging
Main (Discharge)	Delivers the primary current to the device or charger; handles high current demands during discharge and charge.
Balance Connector	Multi-wire connector linked to each cell; allows monitoring and balancing of individual cell voltages during charging to ensure uniform charge and prevent damage.

Note: If you want to know how to charge lipo battery packs safely, always use both the main connector and the balance connector with your lipo battery charger.

Using the right battery terminal connectors for both power and balance connections gives you better performance, longer battery life, and more reliable operation. High-quality connectors and careful handling of all terminals help you avoid common problems like overheating, poor connections, or cell damage. Always inspect your lithium battery terminals for wear and keep them clean for the best results.

Types of Battery Terminal Connectors

When you work with lithium polymer batteries, you will see many different battery terminal connectors. Each type of terminal has its own shape, size, and job. Knowing the types of terminals helps you pick the right one for your project. Let’s look at the most common battery terminals you will find.

XT Series (XT30, XT60, XT90)

The XT series is one of the most popular choices for battery terminal connectors. You will find XT30, XT60, and XT90 terminals in many RC vehicles, drones, and electric bikes. These terminals use gold-plated bullet contacts inside a yellow nylon shell. The design keeps the connection tight and safe. XT terminals are polarized, so you cannot plug them in the wrong way.

Here is a table to help you compare the XT series:

Connector	Current Rating (Amps)	Typical Applications	Key Features
XT30	Up to 30	Small drones, RC vehicles, compact devices	Compact, lightweight, secure connection, ideal for space-limited projects
XT60	Up to 60	Medium-power RC devices, drones, e-bikes	Secure locking mechanism, durable, widely used, handles medium current loads
XT90	Up to 90-120	High-power RC vehicles, electric bikes, industrial equipment	Heavy-duty construction, low resistance, anti-spark versions, robust and reliable

XT30 terminals work best for small devices that do not need much current.
XT60 terminals are great for most RC cars and drones. They handle up to 60 amps.
XT90 terminals are larger and can handle up to 120 amps. Use them for big RC trucks or electric bikes.

Tip: XT connectors are replacing older post terminal connectors in many hobby projects because they are safer and more reliable.

You will notice that all XT battery terminals have a secure locking system. This keeps your connection strong, even if your device shakes or moves. The gold-plated contacts inside the terminal reduce resistance and heat. You get a stable flow of power, which protects your lithium battery terminals and your device.

EC Series (EC3, EC5, EC8)

The EC series includes EC3, EC5, and EC8 battery terminal connectors. These terminals use blue plastic shells and gold-plated bullet contacts. EC terminals are easy to solder because the bullet contacts are separate from the shell. You can use EC battery terminals in RC helicopters, drones, and some cars.

Here is a table that shows the main features of EC series terminals:

Connector Model	Nominal Current	Peak Current	Contact Resistance	Housing Material	Metal Contact Material	Color	Life Cycle
EC3	80A	190A	0.55 Ω	PA (Plastic)	Gold-plated Brass	Blue	1000 cycles
EC5	80A	190A	0.55 Ω	PA (Plastic)	Gold-plated Brass	Blue	1000 cycles
EC8	80A	190A	0.55 Ω	PA (Plastic)	Gold-plated Brass	Blue	1000 cycles

EC3 terminals are smaller and fit 12-14 AWG wires.
EC5 and EC8 terminals are larger and can handle thicker wires for more current.

You will find EC battery terminals in high-power RC vehicles and some drones. These terminals are easy to solder, but you must check the polarity before connecting. EC terminals are not as strong as XT terminals, but they still provide a good connection for most uses.

Here is a quick comparison between EC and XT series:

Feature	EC Series Connectors	XT Series Connectors
Terminal Type	Bullet terminals, separate from body	Bullet terminals, molded into housing
Soldering	Easier	Slightly harder, risk of melting plastic
Build Strength	Not as robust	Stronger, more durable
Connection Safety	Must check polarity	One-way, prevents reverse polarity
Usage	RC helicopters, drones, ARRMA vehicles	RC cars, drones, chargers, high current apps

Note: EC battery terminals are still common in some RC brands, but XT terminals are becoming more popular for new projects.

Deans and T-Plug

Deans connectors, also called T-Plug connectors, have a flat, T-shaped design. You will see these battery terminal connectors in many RC cars and airplanes. Deans terminals use a red plastic shell and gold-plated contacts. The original Deans terminals use high-quality plastic that resists heat. Generic T-Plugs may use cheaper plastic and can melt during soldering.

Deans terminals support up to 60 amps continuous and 75 amps peak.
Use 14 AWG wires with these battery terminals for best results.

You will notice that real Deans connectors connect smoothly and last longer than generic T-Plugs. Both types of terminals are compact and provide a secure fit. Many hobbyists still use Deans battery terminals because they are reliable and protect against reverse polarity.

Connector Type	Continuous Current Rating	Peak Current Rating	Recommended Cable
Deans / T-Plug	60A	75A	14 AWG

Tip: Always choose genuine Deans terminals for better durability and safer connections.

JST and JR

JST and JR connectors are small battery terminal connectors used for low-current jobs. You will find these terminals on balance leads, radio receivers, servos, and small battery packs. JST terminals come in many shapes, but the most common are JST-XH (for balance leads) and JST-RCY (for small power connections).

Here is a table that shows how you might use JST and JR terminals:

Connector Type	Typical Application in LiPo Battery Setups	Current Rating	Cable Gauge	Key Features	Manufacturer Usage
JR	Radio receiver, servos, ESCs, telemetry	~3A	28-24 AWG	3-pin, power and signal	Universal in RC
JST-XH	LiPo battery balancer cables	3A	30-22 AWG	White housing, tight fit	Most RC battery makers
JST-RCY	Auxiliary equipment, small battery packs	5A/10A	28-22 AWG	2-pin, locking, sturdy	Many manufacturers

JST battery terminals are not for high current. Use them for signals or small devices. JR terminals are common for connecting servos and receivers in RC models.

You can see the current and voltage limits for different JST terminals in this chart:

Grouped bar chart comparing current and voltage ratings for various JST connector series

Note: Always check the current rating before using JST or JR terminals for power. Using them for high current can cause overheating.

Molex and IC3/IC5

Molex connectors are small, white battery terminal connectors. You will see them on small battery packs, balance leads, and some consumer electronics. Molex terminals are not for high current, but they are easy to use and fit tightly.

IC3 and IC5 terminals are newer battery terminal connectors. You will find them on some lithium polymer batteries, especially those made for Spektrum Smart systems. IC3 and IC5 terminals look similar to EC3 and EC5, but they have extra pins for smart features. These terminals are backwards compatible with EC3 and EC5, so you can use them with older devices.

Here is a table with some details:

Specification	Value
Battery Type	LiPo (3.7V/cell)
Voltage	7.4V (2S)
Capacity	4000mAh
Connector Type	IC3
Wire Gauge	13 AWG
Maximum Charge Current	1.5C
Maximum Charge Rate	6.0A

IC3 and IC5 terminals provide a solid connection and resist heat. You can use them for medium to high current needs. Molex battery terminals are best for small devices and balance leads.

Tip: If you use Spektrum Smart batteries, IC3 and IC5 terminals let you access extra features like automatic battery data tracking.

You now know the main types of battery terminal connectors. Each terminal has its own strengths. Choose the right battery terminals for your device, current needs, and safety. Always check the current rating and make sure your terminals fit tightly. This will help your lithium battery terminals last longer and work better.

Choosing Battery Terminals

Selecting the right terminals for your lithium polymer battery is important for safety, performance, and reliability. You want to make sure your battery terminals match your device’s needs. Here’s how you can choose the best terminal for your project.

Current Rating

Start by checking the current rating of your terminals. Each terminal has a maximum amount of current it can safely handle. If your device draws more current than the terminal can support, you risk overheating or damaging your battery terminals. For example, if your device needs 60 amps, pick terminals rated for at least 60 amps. Always match the current rating of your terminals to your battery and device. The wire size compatibility also matters. Use terminals that fit the wire gauge you plan to use. Most lithium battery terminals in RC hobbies use 12AWG wire, which works well for short runs and high current.

Tip: Never use terminals with a lower current rating than your device requires. This keeps your battery terminals safe and helps your system last longer.

Compatibility

Compatibility means your terminals must fit both your battery and your device. Using incompatible terminals can cause poor connections, charging problems, or even safety hazards. Always check that your terminals match the connectors on your battery and charger. For lithium battery terminals, make sure the polarity is correct to avoid damage. If you use different brands, double-check the fit and design. Good compatibility improves performance and reliability.

Application Needs

Think about how and where you will use your battery terminals. Some terminals work better in harsh environments because they resist corrosion. Others are easier to install or remove. Consider the size of your device, the space for terminals, and how often you will connect or disconnect them. Choose terminals made from high-quality materials like brass or copper for better conductivity and durability. If your device moves or vibrates, pick terminals with a locking mechanism for a secure fit.

Here’s a simple checklist to help you choose the right terminal:

Check the current rating and wire size compatibility.
Make sure the terminals fit your battery and device connectors.
Pick terminals that match your application’s environment (heat, moisture, vibration).
Choose high-quality materials for better performance and reliability.
Look for easy installation and a secure connection.

Application Need	Recommended Terminal Type	Current Rating	Wire Size Compatibility	Special Features
Small RC Drone	XT30, JST	Up to 30A	16-20 AWG	Compact, lightweight
Medium RC Car	XT60, Deans	Up to 60A	12-14 AWG	Secure fit, easy to use
Large RC Truck/Plane	XT90, EC5, IC5	Up to 120A	10-12 AWG	High current, robust
Consumer Electronics	Molex, JST	Up to 5A	22-28 AWG	Small, tight connection
Outdoor/Harsh Use	XT60, EC5	60-120A	10-12 AWG	Corrosion-resistant, durable

Choosing the right battery terminals helps you get the best performance and reliability from your lithium polymer batteries. Always follow this checklist to keep your system safe and efficient.

Connection Safety

When you work with lithium polymer batteries, you must pay close attention to safety and compliance. These batteries store a lot of energy in a small space. If you do not handle connections properly, you risk damaging your battery or even causing a fire. Following best practices for installation and handling helps you avoid accidents and keeps your devices running smoothly.

Safe Connection Steps

You should always follow a careful process when connecting battery terminals. This ensures a secure connection and reduces the risk of short circuits or overheating.

Inspect the connectors for dirt, damage, or loose wires before making any connections.
Align the connectors so the positive and negative terminals match up correctly.
Push the connectors together firmly until you feel or hear a click. This confirms a secure connection.
Double-check that the connection is tight and there are no exposed wires.
If your battery has a balance connector, connect it to the charger or device as well.

Tip: Always use certified batteries and chargers. Charging in a fire-retardant bag adds another layer of safety.

Safe Disconnection Steps

Disconnecting your battery also requires care. You want to avoid pulling on the wires or forcing the connectors apart.

Hold the connector housing, not the wires, when you disconnect.
Pull the connectors straight apart to avoid bending the pins.
Remove the balance connector gently if your battery uses one.
Store the battery in a safe, cool place after disconnecting.

A secure connection during both connection and disconnection helps prevent damage and keeps your battery healthy.

Mistakes to Avoid

Many safety incidents happen because of simple mistakes with connections. Here are some common errors and how you can avoid them:

Never force connectors together if they do not fit. This can cause short circuits.
Do not use damaged or dirty connectors. These can lead to poor connections and overheating.
Avoid connecting batteries with mismatched connectors or reversed polarity.
Never leave batteries charging unattended.
Do not store multiple batteries together without insulation between the terminals.

Lithium polymer batteries can fail if you drop them, use the wrong charger, or expose them to high temperatures. You might see swelling, bulging, or even fire if something goes wrong. Protection circuits help, but you must still follow proper installation and maintenance steps. Always monitor your batteries for signs of damage and follow manufacturer instructions for safety and compliance.

Remember, following best practices for installation and handling connections keeps you and your devices safe.

Battery Terminals Maintenance

Inspection and Cleaning

You should check your battery terminals often to keep your devices safe and working well. Look for signs of corrosion, loose parts, or any cracks near the terminals. Corrosion can look like white or green powder on the terminals. If you see this, clean it right away. Use a mix of baking soda and water to clean the terminals. This solution helps neutralize any acid and remove corrosion. After cleaning, rinse the terminals with clean water and dry them completely before reconnecting. Always wear gloves and safety glasses when you handle battery terminals. Cleaning your terminals every three months is a good habit. This simple step helps prevent power loss and keeps your battery terminals in top shape.

Tip: Use a wire brush for stubborn corrosion, but be gentle to avoid damaging the terminals.

Handling and Storage

Handle your terminals with care to avoid damage. Always hold the connector, not the wires, when you connect or disconnect. Store your batteries in a cool, dry place. High temperatures and moisture can speed up corrosion and damage the terminals. Use anti-corrosion washers or apply a thin layer of dielectric grease to the terminals for extra protection. Make sure your terminals do not touch metal objects during storage. This prevents accidental short circuits. Following maintenance best practices helps your battery terminals last longer and work better.

Troubleshooting

Sometimes, you may notice problems like loose or damaged terminals, corrosion, or even burnt plastic. These issues can cause your device to lose power or drain the battery faster. If you find loose terminals, tighten them to make sure they stay in place. For rough or corroded terminals, gently sand them to expose fresh metal. If a terminal is cracked or broken, replace it right away. Always use terminal hardware designed for high temperatures. Insulate your terminals to prevent shorts. Regular inspection and proper terminal maintenance help you catch problems early. Remember, proper installation and maintenance keep your battery terminals safe and reliable.

Applications of Lithium Polymer Batteries

Lithium polymer batteries, often called lipo batteries, power many devices you use every day. You see them in RC models, consumer electronics, and custom battery packs. Each application uses lipo batteries for their light weight, high power, and flexible shapes.

RC Models

You find lipo batteries in almost every RC hobby. These batteries give RC planes, quadcopters, helicopters, cars, boats, and trains the energy they need for fast speeds and long run times. Lipo batteries work well in RC models because they deliver high discharge currents. This means your RC car or drone can accelerate quickly and fly or drive for longer. Many RC fans choose lipo batteries because they come in different voltages and sizes, such as 3.7V, 7.4V, or 11.1V. You can pick a lipo battery with the right C rating and configuration for your model.

Tip: Always match your lipo battery’s voltage and C rating to your RC model for the best performance.

Consumer Electronics

Lipo batteries also power many consumer electronics. You use them in smartphones, tablets, cameras, and even some smartwatches. These batteries fit inside slim devices because they are thin and lightweight. Lipo batteries help your electronics last longer between charges. You get more power in a smaller package, which makes your devices easier to carry and use.

Custom Battery Packs

You can build custom battery packs with lipo cells for special projects. Many people use custom lipo packs for robotics, DIY gadgets, or backup power. Lipo batteries can be made in different shapes, sizes, and voltages to fit your needs. You might need a pack with more capacity or a special shape for your project. Lipo batteries give you the flexibility to design the perfect power source.

Here is a table that shows how lipo batteries are used in different areas:

Category	Details
Applications	RC planes, quadcopters, helicopters, cars, boats, trains, toys, big drones, UAVs, agriculture planting
C Ratings	5C, 10C, 15C, 20C, 25C, 30C, 35C, 40C, 50C, 60C, 75C, 85C
Configurations	1S, 2S, 3S, 4S, 6S, 10S
Voltages	3.7V, 7.4V, 11.1V, 14.8V, 22.2V, 37V
Customization	Packs can be made with different capacities, dimensions, and configurations to meet specific needs

Lipo batteries power fast RC vehicles and aircraft.
You use lipo batteries in many drones and UAVs.
Custom lipo packs can fit almost any project.

Lipo batteries give you reliable power for many uses. You can choose the right lipo battery for your hobby, device, or custom project.

You now know how to choose and care for lipo connectors and terminals. Use these steps to keep your lithium polymer battery safe and strong:

Pick terminals that match your lipo application and current needs.
Make secure connections using proper methods and check for tightness.
Inspect terminals for corrosion or damage and clean them often.
Use covers and anti-corrosion grease for better safety and performance.
Always use quality connectors and remove them after use.

Bar chart comparing electrical resistance of battery terminal materials

Check your own lipo connections today or share your tips with others. With the right information, you can make safe, reliable connections every time.

FAQ

What happens if I connect the wrong battery terminals?

You risk short circuits, overheating, or damaging your device. Always check the connector shape and wire colors before connecting. If you force the wrong connection, you could cause a fire or ruin your battery.

Can I mix different connector types on my battery and device?

No, you should not mix connector types. Connectors must match to ensure a safe and secure fit. If you need to connect different types, use an adapter made for your connectors.

How do I know which connector my device needs?

Check your device manual or look at the existing connector. You can also:

Match the connector shape and color
Check the current rating
Ask the manufacturer for advice

Tip: Always use connectors rated for your device’s power needs.

Why do some batteries have two connectors?

You see two connectors because one delivers power (main connector) and the other balances the cells (balance connector). Both keep your battery safe and working well. Always use both when charging for the best results.