Skip to Content
  1. All products
  2. ⚡ Power & Management
  3. 12.6V BMS 3S 20A 18650 Lithium Battery Management Board
  4. ⚡ Power & Management
Pricelist: Retail Price (B2C) Pricelist
Pricelist: Retail Price (B2C) Pricelist
12.6V BMS 3S 20A 18650 Lithium Battery Management Board

12.6V BMS 3S 20A 18650 Lithium Battery Management Board

(0 review)
SpecificationDetails
Cell Configuration3 Series (3S) Li-ion/Li-Po
Charging Voltage12.6V to 13.0V DC
Max Continuous Current13A
Peak Surge Current20A
Overcharge Detection4.25V ± 0.05V (per cell)
Over-discharge Detection2.5V ± 0.08V (per cell)
Internal Resistance< 100mΩ
Price
₹ 67.80 ₹ 67.80
(Tax included)

Product Description

The 3S 20A BMS module acts as a hardware safeguard for your battery pack, monitoring the voltage of each of the three cells individually. If any cell falls outside of the safe operating range, the module disconnects the load or charger to prevent cell swelling or fire. This board is designed for a service life of over 30,000 hours and features a compact, rectangular footprint (approx. 59mm x 20mm) that allows it to be integrated directly into vacuum cleaner battery replacements or solar-powered backup units.

Key Features

  • Enhanced Current Limit: Supports a continuous 13A discharge and handles startup surges up to 20A, suitable for small power tools.

  • Low Standby Drain: Features an ultra-low quiescent current (< 30uA), ensuring your battery pack doesn't drain while in storage.

  • Automatic Recovery: Automatically restores power to the load once a short-circuit condition is removed or a charger is connected.

  • Versatile Pads: Clearly labeled soldering pads for B+, B1, B2, and B- ensure straightforward wiring of the series cells.

  • Broad Temperature Range: Reliable operation from -40°C to +80°C, making it suitable for both indoor and outdoor IoT deployments.

Technical Details

  • Dimensions: 59mm x 20mm x 3.4mm.

  • Protection Delay: Built-in delay for over-discharge and overcurrent to prevent nuisance tripping.

  • PCB Quality: Double-sided PCB with thick copper traces to manage high current without excessive heat.

Prototyping and Engineering Tips from Robogears

  • Wiring Order is Mandatory: To prevent the protection IC from locking up, always wire in this sequence: B- (0V) → B1 (3.7V) → B2 (7.4V) → B+ (11.1V). Do not skip the intermediate B1/B2 taps; the BMS must see the voltage of every individual cell to function.

  • The "Wake-up" Charge: If you measure 0V at the P+/P- pads after assembly, the BMS is likely in "Sleep" mode. Connect a 12.6V charger to the output terminals for a few seconds to activate the circuit.

  • Cell Matching: Ensure all three 18650 cells have the same voltage and internal resistance. If one cell is weaker, it will hit the 2.5V cutoff sooner than the others, causing the BMS to shut down the entire pack even if the other two cells are full.

  • P+ / P- Sharing: Note that the P+ and P- pads are used for both charging and discharging. Never attempt to charge the batteries through the B+/B- pads, as this bypasses the safety protections.

Package Includes

  • 1 x 3S 20A 12.6V 18650 Lithium Battery Management Board (BMS)

Disclaimer

Not compatible with LiFePO4 batteries. Ensure your cells are rated for high-discharge use if you plan to draw the full 20A peak current.