# 5S, 21.0V balance mode

> Balance module for Li-Ion battery packs, 5S, 21.0VDC. Connects to the balance port and equalizes cell voltage to 4.2VDC per cell, using an integrated resistor to limit cells that reach the threshold. Balance current 66mA per cell. Works together with a BMS that has no balance function. Provides no overcharge or overdischarge protection, for which a separate BMS board is required.

- Page: https://sigmanortec.ro/en/5s-210v-balance-mode
- Price: 14.99 RON
- Availability: In stock; 1-2 zile
- Reference: 9469 · EAN: 5943136471212
- Category: Electronic components > Modules for Batteries > Charging and Balancing Modules
- Specifications: Technology: Lithium Ion; Load voltage: 21.0VDC; sway: Yes; Number of cells: 5S
- Package (shipping data): 0.002 kg
- Updated: 2026-09-23
- Shop: [Sigmanortec.ro](https://sigmanortec.ro/en/llms.txt)
- Prices: RON, VAT included; prices and stock as of 2026-10-22 02:22 (Europe/Bucharest)

## Description

Automatically equalizes the voltage of cells in 5S 21.0V Li-Ion packs, by connecting to the balance port, ensuring uniform charging at 4.2V per cell. Works with BMS without balance function, limits cells reached the threshold through integrated resistor, balance current 66mA per cell, useful for maintaining battery performance and lifespan.
The module for balancing 5 3.7V batteries in series. By attaching the balance port of the battery in 4S configuration to this module, the individual cells will be charged at the same voltage. the module works correctly together with a BMS that does not have a balance.
When the battery is charged, the module detects the cells that have reached the 4.2VDC threshold and blocks, with the help of the integrated resistor, the charging of those cells while the uncharged cells still catch up with the charged ones.
The balancing plate does not have any kind of protection when charging or discharging. A BMS board is needed for protection.
If there are differences in internal resistance between the cells, there will also be a difference in tension between the equalized cells. For example, at a difference of 5 milliohms between the cells, the final voltage will differ by up to 0.03, which translates into cells charged at slightly different capacities. For this reason, it is good practice for the cells to have an internal resistance as close as possible.
Specifications:
Compatible batteries: 5S, 21.0VDC, lithium
Individual cell maximum voltage: 4.2VDC
Balanced current per cell: 66mA