2S 7.4V 10A Li-ion Battery Protection Board Balancer BMS

2S 7.4V / 8.4V 10A Battery Charge Protection Board with Balancer Equalizer

Keep your 2-cell lithium-ion battery packs performing at their best with this compact 2S Charge Protection Board with Balancer Equalizer. Designed for 7.4V (nominal) / 8.4V (fully charged) 2S Li-ion packs, this module provides overcharge, over-discharge, and overcurrent protection while actively balancing both charging and discharging cycles — extending battery life and maintaining consistent cell health across your pack.

At just approximately 47 × 24 × 4 mm, this ultra-slim PCB fits neatly into power tool battery housings, RC vehicles, DIY electronics projects, and custom battery packs without adding bulk. With a continuous current rating of 10A, it's built for real-world power demands.

Key Features

• 2S Li-ion BMS: Supports 2-cell series lithium-ion / lithium-polymer battery configurations
• Voltage Range: 7.4V nominal / 8.4V fully charged
• Max Continuous Current: 10A charge and discharge
• Active Balancing: Balances cells during both charging and discharging for even cell wear
• Protection Functions: Overcharge, over-discharge, overcurrent, and short-circuit protection
• Compact Form Factor: Approx. 47 × 24 × 4 mm — easy to integrate into custom enclosures
• Broad Compatibility: Suitable for power tools, RC packs, e-bikes, DIY electronics, and more

Usage Tips

For best results, ensure that all batteries in the pack are identical in chemistry, capacity, and internal resistance — ideally from the same production batch and at the same state of charge before assembly. This allows the balancer to operate most effectively and maximises the longevity of your battery pack.

Specifications

• Cell Configuration: 2S (2 cells in series)
• Nominal Voltage: 7.4V
• Charge Cutoff Voltage: 8.4V
• Rated Current: 10A
• Dimensions: Approx. 47 × 24 × 4 mm
• Compatible Chemistry: Li-ion / LiPo

For further guidance on lithium battery safety and best practices, visit the U.S. Consumer Product Safety Commission (CPSC) — Lithium-Ion Battery Safety Information.

Frequently Asked Questions

Q: What does a 2S battery charge protection board with balancer do?

A: A 2S Battery Management System (BMS) protection board monitors and manages a 2-cell series lithium-ion battery pack. It prevents individual cells from being overcharged beyond 4.2V or discharged below their safe minimum, guards against overcurrent and short-circuit events, and actively balances the charge level between both cells during charging and discharging — helping maintain even cell wear and maximising overall pack lifespan.

Q: What battery packs is this 2S 7.4V 10A protection board compatible with?

A: This board is compatible with any 2S lithium-ion or lithium-polymer (LiPo) battery pack with a nominal voltage of 7.4V and a maximum charge voltage of 8.4V. Common applications include power tool battery packs, RC car and drone batteries, e-bike auxiliary packs, portable lighting systems, and custom DIY electronics projects drawing up to 10A continuous current.

Q: Do I need to match the batteries before using this balancer board?

A: Yes — for optimal balancing performance, it is strongly recommended to use batteries that are identical in brand, chemistry, capacity (mAh), and internal resistance. Ideally, use cells from the same production batch and ensure they are at the same state of charge before assembling the pack. Mismatched cells can reduce the effectiveness of the balancer and may shorten pack life.

Q: How large is this protection board and how do I install it?

A: The board measures approximately 47 × 24 × 4 mm, making it compact enough to fit inside most battery housings and custom enclosures. Connect the B– and B+ terminals to the negative and positive ends of your cell stack respectively, and the balance wire(s) to the mid-point between cells. Always refer to the wiring diagram included with the module, and ensure connections are secure before applying load.