Why Choose Custom Lithium Ion Battery Pack?
Off-the-shelf batteries work for consumer electronics, but industrial applications demand precision. When your device requires specific voltage, capacity, or form factor, custom lithium ion battery pack becomes the only viable solution.
Custom battery packs solve three critical problems:
- Space optimization – Battery shaped exactly to your product enclosure
- Performance matching – Voltage and capacity matched to your power consumption
- Safety compliance – Built-in BMS designed for your specific application
At Flion Power, we’ve manufactured over 10,000 custom battery packs since 2013, serving clients from medical device companies to electric vehicle manufacturers.
Custom Battery Pack Design Process
Step 1: Requirement Analysis
Before we start design, we need understand your project requirements:
- Working voltage: What’s your device’s voltage range? (3.6V, 12V, 24V, 48V, or custom)
- Capacity needed: How long should your device run on single charge?
- Discharge rate: Continuous current and peak current draw
- Physical constraints: Maximum dimensions and weight allowed
- Operating environment: Temperature range, vibration, humidity exposure
- Certification requirements: UL, CE, UN38.3, IEC standards needed
Step 2: Cell Selection
Based on your requirements, we select appropriate lithium ion cells:
| Cell Type | Typical Capacity | Best For |
| 18650 Cylindrical | 2.2-3.5Ah | High power applications, power tools |
| 21700 Cylindrical | 4.0-5.0Ah | E-bikes, energy storage, EV |
| LiFePO4 Prismatic | 5-300Ah | Solar storage, marine, RV |
| LiPo Pouch | 0.1-100Ah | Drones, wearables, slim devices |
For high-drain applications like power tools, we recommend high-rate 18650 cells with 20A+ continuous discharge capability. For energy storage systems, LiFePO4 cells offer 6000+ cycle life and superior safety.
Step 3: BMS (Battery Management System) Design
BMS is the brain of your battery pack. Our BMS design includes:
- Over-charge protection: Cuts off at 4.25V per cell (or 3.65V for LiFePO4)
- Over-discharge protection: Disconnects at 2.5V per cell (or 2.0V for LiFePO4)
- Over-current protection: Limits discharge to safe levels
- Short circuit protection: Instant shutdown on short circuit
- Cell balancing: Ensures all cells charge/discharge evenly
- Temperature protection: NTC sensors monitor battery temperature
For smart applications, we can integrate CAN bus, RS485, or Bluetooth communication for real-time monitoring.
Step 4: Mechanical Design
We design battery housing considering:
- Material selection: ABS plastic for consumer products, aluminum for high-power applications
- Connector type: XT60, XT90, Anderson, or custom connector
- Wiring gauge: Calculated based on maximum current
- Thermal management: Heat dissipation design for high-power packs
Step 5: Prototyping and Testing
Before mass production, we build prototypes for validation:
- Capacity test at 0.2C discharge rate
- Internal resistance measurement
- High-rate discharge testing
- Over-charge and over-discharge safety tests
- Short circuit protection verification
- Temperature rise monitoring
Key Parameters for Custom Battery Pack
When ordering custom battery pack, these parameters must be clearly specified:
Voltage Configuration
Lithium ion cell nominal voltage is 3.6V or 3.7V. Battery pack voltage depends on series connection:
- 1S = 3.6V (1 cell in series)
- 3S = 10.8V (3 cells in series)
- 4S = 14.4V (4 cells in series)
- 10S = 36V (10 cells in series)
- 13S = 46.8V (13 cells in series, commonly called 48V)
Capacity Configuration
Parallel connection increases capacity while keeping voltage same:
- 1P = Single cell capacity
- 2P = Double capacity
- 3P = Triple capacity
Example: 10S3P configuration with 3.5Ah 18650 cells = 36V × 10.5Ah = 378Wh
Discharge Rate
Discharge rate measured in C-rate:
- 1C = Full capacity discharged in 1 hour
- 3C = Full capacity discharged in 20 minutes
- 10C = Full capacity discharged in 6 minutes
For power tools requiring 30A continuous current from 5Ah battery: Required C-rate = 30A ÷ 5A = 6C
MOQ and Lead Time
Minimum Order Quantity
Our MOQ policy designed for both small and large buyers:
- Sample order: 1-5 pieces (for evaluation and testing)
- Small batch: 50-100 pieces (for pilot production)
- Mass production: 500+ pieces (best unit price)
We understand startups and R&D teams need small quantities first. Sample orders welcome, though unit price higher than mass production.
Production Lead Time
Typical lead time after order confirmation:
| Order Quantity | Lead Time |
| 1-10 pieces | 7-10 days |
| 10-100 pieces | 10-15 days |
| 100-500 pieces | 15-20 days |
| 500+ pieces | 20-30 days |
Custom tooling (plastic housing mold) may add 15-20 days for first order.
Application Case Studies
Case 1: Electric Bicycle Battery
Client requirement: 36V 15Ah battery for city e-bike, maximum dimensions 360×90×110mm
Our solution:
- Cell: 10S5P configuration using Samsung 35E 3.5Ah cells
- BMS: 36V 25A continuous, with Bluetooth app
- Housing: Custom aluminum alloy case with quick-release mount
- Connector: XT60 with Anderson charging port
Result: 540Wh battery pack, 60-80km range per charge, 800+ cycles warranty
Case 2: Medical Device Battery
Client requirement: 12V 8Ah battery for portable ultrasound, must pass IEC 60601-1 medical certification
Our solution:
- Cell: 3S3P LiFePO4 26650 cells (safer chemistry for medical use)
- BMS: Medical-grade with isolation, LCD display showing SOC/SOH
- Housing: ABS+PC flame retardant material, IP54 rated
- Certification: Passed IEC 60601-1, UN38.3, CE medical
Result: 96Wh LiFePO4 battery, 2.5kg weight, 2000+ cycle life
Case 3: Energy Storage System
Client requirement: 48V 100Ah battery for solar off-grid system
Our solution:
- Cell: 16S1P 100Ah LiFePO4 prismatic cells
- BMS: 48V 100A with RS485 communication, compatible with Vic inverters
- Housing: Steel enclosure with IP65 rating, integrated busbars
- Features: Parallel connection support up to 16 units
Result: 5.12kWh battery module, 6000+ cycles, 10-year design life
Why Choose Flion Power for Custom Battery Pack?
With 12 years of lithium battery manufacturing experience, here’s what makes us different:
- Factory direct pricing – No middleman, save 20-30% cost
- Small MOQ accepted – Start from 1 piece for sample evaluation
- Fast turnaround – 7 days for sample, 15 days for mass production
- Quality assurance – 100% inspection before shipment, 1-3 years warranty
- Technical support – Professional engineers available for design consultation
- Certification support – We help you pass UL, CE, UN38.3 certification
Our factory covers 5,000 square meters with 50+ skilled workers. Monthly production capacity reaches 50,000 battery packs.
Get Your Custom Battery Pack Quote
Ready to start your custom battery project? Here’s how to proceed:
- Send inquiry – Email us your requirements (voltage, capacity, dimensions, application)
- Receive quotation – We provide detailed quote within 24 hours
- Confirm order – Approve design drawing and place order
- Production and delivery – We manufacture and ship to your door
Contact Flion Power today for professional custom lithium ion battery pack solution. Our engineers ready to help you design perfect battery for your application.
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