4S 18650 Li-ion BMS Protection Board PCB 4A–5A | 1–5 Pack
4S 18650 Li-ion BMS Protection Board PCB 4A–5A | 1–5 Pack
4S 18650 Li-ion Lithium Battery BMS Protection Board – 4A to 5A
Keep your 4-series 18650 lithium-ion battery packs safe and running at peak performance with this compact 4S BMS (Battery Management System) Protection Board. Engineered for hobbyists, makers, and electronics enthusiasts, this PCB module guards against overcharge, over-discharge, and overcurrent — extending the life of your battery packs and protecting your projects.
Made in Mainland China.
Key Features
- 4S Configuration: Designed specifically for 4-cell series 18650 lithium-ion battery packs.
- Wide Voltage Range: Supply voltage 4.25V–4.35V; discharge cutoff 2.3V–3.0V for full cell-protection coverage.
- 4A–5A Continuous Current: Handles up to 5A continuous discharge with reliable overcurrent protection.
- Overcharge Protection: Automatically cuts off charging when individual cells reach maximum safe voltage.
- Over-Discharge Protection: Prevents deep discharge that can permanently damage lithium-ion cells.
- Overcurrent & Short-Circuit Protection: Instantly disconnects load under fault conditions.
- Wide Operating Temperature: Rated from –40°C to +50°C for use in demanding environments.
- SMD Package: Compact surface-mount design fits neatly into custom battery enclosures and DIY builds.
- Flexible Quantity: Available in 1 to 5 pieces — stock up and save for multiple projects.
Specifications
| Cell Configuration | 4S (4 cells in series) |
| Compatible Cell | 18650 Li-ion / Lithium |
| Supply Voltage | 4.25V – 4.35V |
| Discharge Cutoff Voltage | 2.3V – 3.0V |
| Continuous Current | 4A – 5A |
| Dissipation Power | 3A |
| Operating Temperature | –40°C to +50°C |
| Package Type | SMD |
| Condition | New |
| Origin | Mainland China |
What's in the Box?
- 1–5 × 4S BMS Li-ion Battery Protection Board PCB (quantity selected at checkout)
Perfect For
- DIY battery pack builds and rebuilds
- RC vehicles, power tools, and portable electronics
- Laptop and computer battery upgrades
- Robotics, Arduino, and maker projects
- Any 4S 18650 lithium-ion battery application requiring reliable cell protection
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Frequently Asked Questions
Q: What does a 4S BMS protection board do for 18650 lithium-ion batteries?
A: A 4S BMS (Battery Management System) protection board monitors and controls four series-connected 18650 lithium-ion cells. It prevents overcharging (above 4.25–4.35V per cell), over-discharging (below 2.3–3.0V per cell), and overcurrent or short-circuit events, keeping your battery pack safe and maximizing its useful lifespan.
Q: Is this BMS board compatible with all 18650 lithium-ion cells?
A: Yes. This board is designed for standard 18650 Li-ion lithium cells arranged in a 4S (4-series) configuration. It supports a supply voltage range of 4.25V–4.35V and a discharge cutoff of 2.3V–3.0V, making it compatible with most common 18650 Li-ion cells used in DIY packs.
Q: Can I use this board for DIY laptop or power-tool battery packs?
A: Absolutely. This PCB BMS is suitable for DIY laptop battery rebuilds, power-tool packs, RC projects, and portable electronics. With a continuous current rating of 4A–5A and wide operating temperature range (–40°C to +50°C), it handles a broad range of practical DIY applications.
Q: How many boards do I receive, and can I order multiple?
A: You can select 1 to 5 boards in a single order. Buying in a multi-pack is ideal if you have several battery projects planned, ensuring you always have a spare board on hand.