Battery 101


1s 3.7V 5A Li-Ion BMS Protection board

1s Li-Ion 5A 3.7V Protection board is a circuit board designed to protect a single cell Lithium-ion battery with a nominal voltage of 3.7V and a maximum current output of 5A.

The board typically contains a protection IC (integrated circuit) which monitors the battery voltage and current, and prevents overcharging, over-discharging, and over-current conditions that could damage the battery or create a safety hazard.

Overall, this 1S 3.7V 5A Li-ion protection board is an important safety feature for any device that uses a single cell Li-ion battery, such as a flashlight, remote control, or portable electronic device.


  • Model: 1S Li-ion – 3.7V-4.2V
  • Over-charge Voltage Range: 4.25V ± 0.05V
  • Over-discharge Voltage Range: 2.65V ± 0.1V
  • Cont. discharge current Current: 5A
  • Max discharge Current: 10A
  • Quiescent Current: <30uA
  • Charging voltage: 4.2V
  • Chemistry: Li-Ion
  • B+: Battery V+ Positive
  • B-: Battery V- Negative
  • P+: Output / Charging V+
  • P-: Output / Charging V-
  • Product size: 30 x 7 x 2.2mm

Package included: 1 x Li-ion Battery 1S 5A Protection board



This BMS will require a competent and knowledgeable person with an electronic background and skills to install and operate. As these are sensitive products, we will only accept returns if its un-opened and un-used. 

Please double check and triple check your wiring, especially the balance/sense wires are correct. Even temporary incorrect wiring may damage this device.

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