4S NiMH/NiCd Battery Charger Module
| Battery Pack | Input Voltage | Charging Voltage (set by R1) | R1 Value (kΩ) | Charging Current (set by RCS) | LED Indicators | Key Features |
| 1S (1 Cell) | 4.5 - 5.5V DC | 1.35-7V | 10.0 | Pre-charge: ~100 mA Fast charge: ~250 mA (RCS 1–10 Ω, larger = lower current) |
ON: powered, not charging Slow Flash (~1 Hz): charging Fast Flash (~10 Hz): short/wrong pack OFF: fully charged |
Zero-volt activation, short-circuit protection, automatic stop, safe trickle maintenance |
| 2S (2 Cell) | 4.5 - 5.5V DC | 2.7-3.4V | 10.0 | Pre-charge: ~100 mA Fast charge: ~250 mA (RCS 1–10 Ω, larger = lower current) |
ON: powered, not charging Slow Flash (~1 Hz): charging Fast Flash (~10 Hz): short/wrong pack OFF: fully charged |
Zero-volt activation, short-circuit protection, automatic stop, safe trickle maintenance |
| 3S (3 Cell) | 4.5 - 5.5V DC | 4.05-5.1V | 20.0 | Pre-charge: ~100 mA Fast charge: ~250 mA (RCS 1–10 Ω, larger = lower current) |
ON: powered, not charging Slow Flash (~1 Hz): charging Fast Flash (~10 Hz): short/wrong pack OFF: fully charged |
Zero-volt activation, short-circuit protection, automatic stop, safe trickle maintenance |
| 4S (4 Cell) | 4.5 - 5.5V DC | 5.7-6.8V | 30.0 | Pre-charge: ~100 mA Fast charge: ~250 mA (RCS 1–10 Ω, larger = lower current) |
ON: powered, not charging Slow Flash (~1 Hz): charging Fast Flash (~10 Hz): short/wrong pack OFF: fully charged |
Zero-volt activation, short-circuit protection, automatic stop, safe trickle maintenance |
| 5S (5 Cell) | 4.5 - 5.5V DC | 6.75-8.5V | 40.2 | Pre-charge: ~100 mA Fast charge: ~250 mA (RCS 1–10 Ω, larger = lower current) |
ON: powered, not charging Slow Flash (~1 Hz): charging Fast Flash (~10 Hz): short/wrong pack OFF: fully charged |
Zero-volt activation, short-circuit protection, automatic stop, safe trickle maintenance |
| 6S (6 Cell) | 4.5 - 5.5V DC | 8.1-10.2V | 49.9 | Pre-charge: ~100 mA Fast charge: ~250 mA (RCS 1–10 Ω, larger = lower current) |
ON: powered, not charging Slow Flash (~1 Hz): charging Fast Flash (~10 Hz): short/wrong pack OFF: fully charged |
Zero-volt activation, short-circuit protection, automatic stop, safe trickle maintenance |
| 7S (7 Cell) | 4.5 - 5.5V DC | 9.45-11.9V | 60.4 | Pre-charge: ~100 mA Fast charge: ~250 mA (RCS 1–10 Ω, larger = lower current) |
ON: powered, not charging Slow Flash (~1 Hz): charging Fast Flash (~10 Hz): short/wrong pack OFF: fully charged |
Zero-volt activation, short-circuit protection, automatic stop, safe trickle maintenance |
| 8S (8 Cell) | 4.5 - 5.5V DC | 10.8-13.6V | 69.8 | Pre-charge: ~100 mA Fast charge: ~250 mA (RCS 1–10 Ω, larger = lower current) |
ON: powered, not charging Slow Flash (~1 Hz): charging Fast Flash (~10 Hz): short/wrong pack OFF: fully charged |
Zero-volt activation, short-circuit protection, automatic stop, safe trickle maintenance |
Charging Process
- Battery Detection – Detects insertion and verifies pack voltage.
- Pre-Charge – If cell < 1 V → trickle charge (~100 mA) until safe.
- Fast Charge – Constant ~250 mA until near full (~1.35 V/cell).
- ΔV Cutoff / Top-Up – Automatically stops or enters trickle to prevent overcharge.
- Trickle Mode – Maintains charge, compensates for self-discharge.
- Auto Reset – When battery is removed, charger resets for next use.
Protection Features
- Short-Circuit Protection: Shuts down safely if BAT+ and BAT– are shorted.
- Zero-Volt Activation: Revives deeply discharged packs safely.
- Overvoltage Cutoff: Stops charging if per-cell > 1.35 V.
- Auto Pack Verification: No charging if pack voltage is out of range.
Module Details
- Input Pins: VIN / GND
- Output Pins: BAT+ / BAT–
- Set Resistors:
- R1 → sets charging voltage (per pack size).
- RCS → sets charging current (1–10 Ω recommended).
- LED Indicators: Multi-status (power, charge, short, full).
- Weight: ~2.00 g
- Note: Output voltage cannot be measured with a multimeter without a battery; must use oscilloscope.
