If you’re in need of a high-capacity, reliable lithium battery pack for your electric scooter, e-bike, portable power station, or off-grid device, building a 10S8P battery pack is an excellent choice. This guide will walk you through every step of assembling a 10S8P battery pack using 80 brand-new Samsung 18650 3500mAh cells, a 30A BMS protection board, waterproof and fireproof PVC film, waterproof glue, a DC2.1 charging port, and an XT60 discharge connector. Whether you’re a DIY enthusiast, hobbyist, or small business owner, this step-by-step tutorial is designed to be easy to follow.

A 10S8P battery pack delivers a nominal voltage of 36V (42V when fully charged) and a generous capacity of 28Ah (3500mAh × 8 cells in parallel), making it ideal for powering medium to high-demand devices. By using premium components—including brand-new Samsung 18650 3500mAh cells and a 30A BMS—you’ll ensure long lifespan, stable performance, and safety. We’ve also included a dedicated section for the waterproof and fireproof packaging (PVC film + waterproof glue) to protect the battery from moisture, dust, and fire risks. Plus, we’ve reserved space for you to insert your step-by-step assembly video, making the process even more straightforward. Let’s dive into the details of building your 10S8P battery pack.

What You Need to Know About the 10S8P Battery Pack Configuration

Before starting the assembly, it’s critical to understand the 10S8P configuration and why each component matters. This knowledge will help you avoid mistakes, ensure the battery meets your performance needs, and make troubleshooting easier. Here’s a breakdown of the 10S8P setup and key components:

1. 10S8P Configuration: Voltage & Capacity Explained

The “10S8P” label refers to how the 80 Samsung 18650 3500mAh cells are connected, which directly determines the battery’s voltage and capacity:

10S (10 Cells in Series): 10 lithium-ion cells connected in series deliver a nominal voltage of 36V (each 18650 cell has a nominal voltage of 3.6V; 3.6V × 10 = 36V). When fully charged, the voltage reaches 42V (4.2V × 10), which is compatible with most 36V devices and motors.
8P (8 Cells in Parallel): 8 cells connected in parallel form a single module, boosting the total capacity. With Samsung 18650 3500mAh cells, each 8P module provides 3500mAh × 8 = 28,000mAh (28Ah). This high capacity ensures long runtime for your devices, even during heavy use.
Total Cells: A 10S8P battery pack requires exactly 80 brand-new Samsung 18650 3500mAh cells (10 series groups × 8 parallel cells each). Using brand-new cells ensures consistency, reliability, and maximum performance.

2. Key Components for Your 10S8P Battery Pack

Every component plays a critical role in the battery’s performance, safety, and durability. We’ve specified high-quality parts to ensure your 10S8P battery pack lasts for years—here’s a detailed breakdown:

80 Brand-New Samsung 18650 3500mAh Cells: Samsung 18650 3500mAh cells are premium-grade, with consistent voltage, capacity, and internal resistance. Brand-new cells avoid the risks of used or recycled cells (reduced capacity, cell imbalance, safety hazards) and offer a lifespan of 1000–1500 charge cycles.
30A BMS Protection Board: A 30A smart BMS (Battery Management System) is the “brain” of the battery pack. It protects against overcharge, over-discharge, over-current, short-circuit, and overheating—critical for safety and longevity. The 30A rating is perfectly matched to the 10S8P battery’s output, supporting medium to high-demand devices without tripping.
Waterproof & Fireproof PVC Film: This specialized PVC film wraps the entire battery pack, providing protection against moisture, dust, and fire. It’s essential for outdoor or harsh environments, ensuring the battery remains safe and functional.
Waterproof Glue: Applied to the edges of the PVC film and around connectors (DC2.1 charging head, XT60 discharge head), waterproof glue creates a tight, water-resistant seal, preventing moisture from seeping into the battery and causing damage.
DC2.1 Charging Head: A standard DC2.1 charging port allows you to easily charge the 10S8P battery pack using a compatible 36V lithium battery charger. It’s durable, widely available, and designed for easy insertion and removal.
XT60 Discharge Head: The XT60 connector is a popular choice for high-current applications, offering a secure, low-resistance connection for discharging power to your device. It’s durable, easy to solder, and compatible with most 36V devices (electric scooters, e-bikes, etc.).

Tools & Materials You’ll Need

To build your 10S8P battery pack, you’ll need the following tools and materials. We recommend using high-quality tools to ensure clean, safe connections and proper assembly. All components are easy to find online or at local electronics stores:

80 × Brand-new Samsung 18650 3500mAh lithium-ion cells
1 × 30A BMS protection board (compatible with 10S 36V lithium battery packs)
1 × Waterproof & fireproof PVC film (large enough to wrap the entire battery pack)
1 × Tube of waterproof glue (silicone-based, suitable for electronics)
1 × DC2.1 charging head (female port for charging)
1 × XT60 discharge head (male connector for discharging)
1 × 18650 battery holder or assembly board (to organize 10S8P configuration)
Pure nickel strips (0.15mm–0.2mm thickness, for spot welding)
Spot welder (essential for safe, strong cell connections—avoid soldering)
Multimeter (to test voltage, connections, and cell balance)
14–16 AWG wires (for main power connections and BMS wiring)
Soldering iron & solder (for connecting wires to DC2.1 and XT60 connectors)
Insulation paper (for covering conductive parts)
Hot glue gun (to secure BMS, connectors, and wires)
Insulated gloves (for safety while handling cells and wiring)
Scissors (for cutting nickel strips, PVC film, and wires)

Safety Note: Always work in a dry, well-ventilated area away from flammable materials. Never short-circuit 18650 cells—this can cause overheating, fire, or explosion. Wear insulated gloves at all times during assembly, and avoid touching exposed conductive parts with bare hands.

Step-by-Step Guide to Building a 10S8P Battery Pack

Follow these detailed steps to assemble your 10S8P battery pack. For visual guidance, insert your assembly video in the dedicated section below—this will help you avoid mistakes and ensure each step is done correctly. The process features clear, sequential instructions that are easy to reference.

Step 1: Sort & Match the Samsung 18650 3500mAh Cells

Cell consistency is critical for a reliable 10S8P battery pack. Mismatched cells (different voltage, capacity, or internal resistance) will cause uneven charging/discharging, reduce lifespan, and create safety risks. Here’s how to sort and match your 80 brand-new cells:

Unbox the 80 Samsung 18650 3500mAh cells and inspect them for any physical damage (dents, scratches, or leaks). Discard any damaged cells—they can compromise the entire battery pack.
Use a multimeter to test the voltage of each cell. All brand-new cells should read 3.6V–3.7V (semi-charged), with a maximum difference of 0.05V between cells. If any cell has a voltage outside this range, set it aside (it may be defective).
If you have a cell tester, check the internal resistance of each cell. Cells with similar internal resistance (difference ≤ 10mΩ) will perform better together, ensuring even charging and discharging.
Sort the 80 cells into 10 groups of 8 cells each. Each group will form an 8P parallel module—ensure each group has cells with nearly identical voltage and internal resistance.

Step 2: Build the 8P Parallel Modules

Each 8P module combines 8 Samsung 18650 3500mAh cells to create a 3.6V 28Ah module. Follow these steps to build the parallel groups:

Place 8 cells into the battery holder, ensuring all positive (+) and negative (-) poles are aligned correctly (positive on one end, negative on the other).
Cut two nickel strips to size: one strip for the positive terminals and one strip for the negative terminals of the 8 cells. The strips should be long enough to cover all 8 terminals with a small overlap.
Put on insulated gloves and use a spot welder to weld the nickel strip to the positive terminals of the 8 cells. Weld 2–3 spots per cell to ensure a strong, reliable connection—avoid over-welding, as this can damage the cells.
Repeat the process for the negative terminals, welding the second nickel strip to all 8 negative poles. Double-check the connections to ensure no gaps or loose spots.
Use a multimeter to test the voltage of the 8P module. It should read 3.6V–3.7V. If the voltage is lower or higher than expected, check your welding connections—loose welds can cause voltage drops.
Repeat steps 1–5 to build 10 identical 8P parallel modules (you’ll need 10 modules for the 10S series connection).

Step 3: Connect the 10 Modules in Series (10S) to Reach 36V

Connecting the 10 8P modules in series will raise the total voltage to 36V (10 × 3.6V = 36V nominal). This is the key step to creating your 10S8P battery pack:

Arrange the 10 8P modules in a compact layout (either straight line or stacked, depending on your packaging needs). Ensure there’s enough space for the BMS and wiring.
Cut nickel strips to connect the modules in series: each strip will connect the negative (-) terminal of one module to the positive (+) terminal of the next module. Cut the strips to the appropriate length to avoid excess wire.
Weld one end of the nickel strip to the negative terminal of the first module, then weld the other end to the positive terminal of the second module. Repeat this process for all 10 modules until they are connected in a chain.
After connecting all 10 modules in series, use a multimeter to test the total voltage of the battery pack. It should read 36V–37V (normal for semi-charged cells). If the voltage is lower than expected, check for loose or missing welds between modules.

Step 4: Install the 30A BMS Protection Board

The 30A BMS is critical for the safety and performance of your 10S8P battery pack. Follow these instructions to install it correctly:

Identify the BMS terminals: Most 10S BMS boards have terminals labeled B- (main negative), B1–B10 (balance wires), P- (output negative), and P+ (output positive). Refer to the BMS manual if you’re unsure.
Connect the main negative (-) terminal of the 10S8P battery pack to the BMS B- terminal using a short, thick wire (14 AWG recommended). This wire carries the main current, so it’s important to use a thick enough gauge.
Connect the balance wires: Cut 10 small lengths of wire (18–20 AWG) and connect each series connection point (between modules) to the corresponding BMS balance terminal (B1 to B10). Ensure the balance wires are connected in order—mixing them up will damage the BMS.
Connect the main positive (+) terminal of the battery pack to the BMS P+ terminal using another 14 AWG wire.
Secure the BMS to the battery pack using a hot glue gun. This prevents the BMS from moving during use, which can damage the wires or connections.
Double-check all wiring to ensure no reverse polarity (positive to negative) and no loose connections. A reverse connection can fry the BMS and battery pack.

Step 5: Connect the DC2.1 Charging Head & XT60 Discharge Head

Now it’s time to connect the charging and discharging connectors—DC2.1 for charging and XT60 for discharging. Follow these steps for a secure, reliable connection:

Cut two 14 AWG wires (one for positive, one for negative) for the DC2.1 charging head. Solder one end of the positive wire to the DC2.1’s positive terminal and the negative wire to the DC2.1’s negative terminal. Use heat-shrink tubing to insulate the soldered connections.
Connect the other end of the DC2.1 wires to the BMS: positive wire to BMS P+ and negative wire to BMS P-. This ensures the charger only connects to the BMS, which regulates the charging process.
Repeat the process for the XT60 discharge head: cut two 14 AWG wires, solder them to the XT60’s positive and negative terminals, insulate with heat-shrink tubing, and connect the other ends to BMS P+ and P-.
Use a hot glue gun to secure the DC2.1 and XT60 connectors to the battery pack. Ensure they are positioned so that the ports are easily accessible for charging and discharging.

Step 6: Insulate & Package with Waterproof Fireproof PVC Film & Waterproof Glue

Proper insulation and waterproof packaging are essential to protect the battery pack from moisture, dust, and fire. Follow these steps to ensure a secure, water-resistant seal:

Wrap the entire battery pack (modules, BMS, wires, and connectors) with insulation paper. This covers all conductive parts, preventing short-circuits.
Cut the waterproof & fireproof PVC film to size—ensure it’s large enough to wrap around the entire battery pack with a 2–3cm overlap on all sides.
Wrap the PVC film tightly around the insulated battery pack. Smooth out any wrinkles to ensure a tight fit.
Apply waterproof glue to the overlap of the PVC film, pressing firmly to create a water-resistant seal. Also, apply a small amount of glue around the DC2.1 and XT60 connectors, where the PVC film meets the ports—this prevents moisture from seeping in.
Allow the waterproof glue to dry completely (follow the glue manufacturer’s instructions, typically 2–4 hours). Do not test the battery until the glue is fully dry.

Step 7: Test & Activate the 10S8P Battery Pack

Before using the battery pack, perform these tests to ensure it’s safe, functional, and meets the 36V 28Ah specifications:

Use a multimeter to test the total output voltage (between XT60 positive and negative terminals). It should read 36V–42V (depending on charge level).
Test the charging function: Connect a compatible 36V lithium battery charger to the DC2.1 port. The charger should start charging the battery, and the BMS should regulate the charging process (preventing overcharge).
Test the discharging function: Connect a compatible device to the XT60 port and turn it on. The battery should deliver stable power, with no voltage drops or overheating.
Perform a cell balance test: Charge the battery to full (42V) and use a multimeter to check the voltage of each 8P module. All modules should have nearly the same voltage (difference ≤ 0.05V), indicating the BMS is balancing the cells correctly.
Test the waterproof seal: After the glue is fully dry, gently spray the battery pack with water (avoid direct high-pressure spray) and check for any moisture inside the PVC film. If no moisture is present, the waterproof seal is secure.

Insert Your 10S8P Battery Pack Assembly Video Here

To make the assembly process even easier, we recommend inserting your step-by-step assembly video here. A visual guide will help readers follow along, avoid mistakes, and ensure their 10S8P battery pack is built correctly. Your video should cover all the key steps outlined in this guide, including:

Sorting and matching Samsung 18650 3500mAh cells
Building 8P parallel modules with spot welding
Connecting modules in series (10S) to reach 36V
Installing the 30A BMS protection board
Connecting the DC2.1 charging head and XT60 discharge head
Wrapping the battery pack with waterproof fireproof PVC film and applying waterproof glue
Testing and activating the battery pack

A high-quality assembly video will not only help you follow along more easily but also make the entire process more accessible, even if you’re new to DIY battery assembly.

FAQs About Building a 10S8P Battery Pack

Q1: Why use brand-new Samsung 18650 3500mAh cells?
A: Brand-new Samsung 18650 3500mAh cells are consistent, reliable, and offer maximum capacity. Used or recycled cells often have reduced capacity, inconsistent voltage, and higher internal resistance, which can cause cell imbalance, reduce battery life, and create safety hazards. Samsung cells also have built-in safety features to prevent overheating and short-circuits.

Q2: Can I use a soldering iron instead of a spot welder?
A: No. Soldering generates high heat (over 200°C), which can damage the internal components of 18650 cells, reduce capacity, and create safety risks. Spot welding is the safe, reliable method—it uses short, low-heat pulses to bond nickel strips to cells without damaging them. A cheap portable spot welder is a worthwhile investment for DIY battery assembly.

Q3: What charger should I use for the 10S8P 36V battery pack?
A: Use a dedicated 36V lithium-ion battery charger with a charging voltage of 42V (the full charge voltage for 10S lithium batteries). The charger current should be 2.8A–5.6A (10–20% of the 28Ah capacity) for safe, efficient charging. Do not use a lead-acid charger—this will damage the lithium battery pack.

Q4: How long will the 10S8P battery pack last?
A: With brand-new Samsung 18650 3500mAh cells and proper maintenance, the battery pack will last 3–5 years (1000–1500 charge cycles). Proper maintenance includes charging after use, storing in a cool dry place, and avoiding overcharge/over-discharge.

Q5: Is the waterproof packaging really necessary?
A: Yes, especially if you plan to use the battery pack outdoors (e.g., electric scooters, e-bikes) or in humid environments. The waterproof fireproof PVC film and waterproof glue protect the battery from moisture, dust, and fire, extending its lifespan and ensuring safety.

Conclusion

Building a 10S8P battery pack with 80 brand-new Samsung 18650 3500mAh cells, a 30A BMS protection board, waterproof fireproof PVC film, and the specified connectors is a straightforward process with the right tools and guidance. This battery pack delivers 36V 28Ah of stable power, making it ideal for electric scooters, e-bikes, portable power stations, and other medium to high-demand devices.

By following the step-by-step instructions and inserting your assembly video, you’ll be able to build a safe, reliable 10S8P battery pack that lasts for years.

Remember to prioritize safety throughout the assembly process: use insulated gloves, avoid short-circuiting cells, and double-check all connections. With the right components and careful assembly, your 10S8P battery pack will provide consistent, long-lasting power for all your needs. If you have any questions, need help with components, or require custom battery solutions, feel free to contact us via our official website.