Lii-M4 & Lii-M4S Smart Chargers – Combined Product Details

(Button Version / Touch Upgrade Version)

⚠️ Important – Please Read Before Purchase

• Neither charger has an internal resistance test function. All data shown on the screen (voltage, current, capacity, time, etc.) are for reference only during the charging process. For accurate measurements of battery capacity or internal resistance, please use professional testing equipment.

• Compatible battery types (both models):
  ✅ 1.2V Ni‑MH / Ni‑Cd batteries (AA, AAA, etc.)
  ✅ 3.7V Li‑ion batteries (18650, 21700, 26650, 14500, etc.)

• DO NOT charge (both models):
  ❌ 1.5V Lithium batteries
  ❌ 3.2V LiFePO₄ (LFP) batteries
  ❌ 3.8V IMR Lithium batteries

• 21700 battery note:
  Both chargers support standard flat‑top 21700 cells (length ≤ 70 mm).
  Button‑top or protected (PCB) 21700 batteries exceed 70 mm in length and CANNOT fit into the slots – do not force them.

• The charger may become warm during operation – this is normal. Avoid touching hot surfaces.

• Use a 5V/2.0A power adapter (Type‑C input) for best performance.

Lii-M4 vs. Lii-M4S – Key Differences at a Glance

Both models support 4 independent channels, automatic battery type recognition, capacity testing, USB 5V/1A output, 0V activation, and a full set of safety protections.

Common Core Features (Both M4 and M4S)

🔋 Automatic Battery Type Detection & Default Charge Mode

When you insert a battery into any slot, the charger automatically detects the voltage and displays the type:

• 3.7V → Li‑ion battery

• 1.2V → Ni‑MH / Ni‑Cd battery

The default mode is CHARGE – you can start charging immediately without any operation. To use capacity testing or other modes, you need to manually switch.

📊 LCD Display & Data Reference Note

The large LCD independently shows for each channel:

• Operating mode

• Battery voltage (V)

• Real‑time current (mA)

• Charged / discharged capacity (mAh)

• Elapsed time (h)

• Percentage of charge (%)

Again, all displayed values (capacity, percentage, etc.) are for reference only – they are not lab‑grade precision. For exact battery capacity data, use dedicated testing instruments.

🔄 Capacity Test (TEST Mode) – Both Models

Both chargers feature a TEST mode that runs a charge → discharge → recharge cycle.

• The discharge current is fixed at 500mA for the M4 (and for M4S when charge current is ≥500mA; if charge current is 300mA, discharge is 250mA).

• After the cycle, the screen shows the discharge capacity.

• M4 mainly retains the discharge capacity data; M4S alternately displays both discharge and charge capacity data at the end of the test for comprehensive reference.

🛡️ Multiple Protections (Same for Both)

• Overcharge / over‑discharge protection

• Short‑circuit protection

• Reverse‑polarity protection (shows Err if reversed)

• 0V battery activation (can revive deeply discharged Li‑ion cells)

• Bad battery detection (shows Err)

• Voltage rejection range: 1.65V – 2.2V (prevents charging incompatible batteries)

• Smart voltage termination (–ΔV & 0ΔV)

🔌 USB 5V / 1A Output (Same for Both)

Insert a sufficiently charged Li‑ion battery into Channel 4, and the USB port outputs 5V / 1000mA – ideal for emergency charging of phones, small fans, earphones, etc.

Mode Details (by Model)

【 Lii‑M4 – 2 Modes 】

① CHARGE (Charging Mode)

• Default mode – starts automatically when a battery is inserted.

• Selectable currents: 500mA / 1000mA (1000mA is for Li‑ion only, supports up to 2 channels; if more than 2 channels are used, it automatically drops to 500mA).

• Records charging capacity; displays End when fully charged.

② TEST (Capacity Test Mode)

• Operation: select channel → long‑press MODE to switch to TEST → within 8 seconds press CURRENT to choose current (500/1000mA) → locks and starts.

• Cycle: charge to full → discharge at fixed 500mA (records discharge capacity) → recharge (does not record charge capacity).

• Finally shows discharge capacity, along with End and 100%.

【 Lii‑M4S – 4 Modes (Touch Control) 】

① CHARGE (Charging Mode)

• Same as M4 but with more current options: 300mA / 500mA / 700mA / 1000mA.

• 700mA / 1000mA are for Li‑ion only and support up to 2 channels; if more than 2, it drops to 500mA.

② DISCHARGE (Independent Discharge Mode)

• Performs a constant‑current discharge to measure discharge capacity.

• Selectable discharge currents: 250mA / 500mA (each channel can be set independently).

• Displays End and the discharge capacity (mAh) upon completion.

③ TEST (Charge‑Discharge‑Charge Capacity Test)

• Process: charge (not recorded) → discharge (records discharge capacity – current automatically matches: if charge current ≥500mA, discharge is 500mA; if charge current is 300mA, discharge is 250mA) → recharge (records charge capacity).

• After completion, the screen alternately shows both discharge and charge capacity values for comparison.

• Current selection same as CHARGE mode (300/500/700/1000mA).

④ STORAGE (Li‑ion Storage Mode)

• Only for 3.7V Li‑ion batteries – Ni‑MH does not support this.

• Automatically adjusts battery voltage to 3.70V (optimal storage voltage).

  • Above 3.7V → discharges to 3.7V

  • Below 3.7V → charges to 3.7V

• Stops automatically when 3.7V is reached, displays End – helps prolong battery life.

Control Method – Buttons vs. Touch

Lii‑M4 (Physical Buttons)

• Press‑type buttons with tactile feedback.

• Short‑press to select channels / view data; long‑press MODE to change mode; press CURRENT to adjust current.

• Locks and starts automatically after 8 seconds of inactivity.

Lii‑M4S (Touch‑Sensitive Pads)

• Light touch to operate – no mechanical wear.

• Long‑touch MODE to cycle modes; short‑touch 1‑2 / 3‑4 to view channel data; short‑touch CURRENT to adjust current.

• Long‑touch CURRENT to keep LCD backlight always on.

• Also locks and starts after 8 seconds of inactivity.

Tip: Always select the channel first, then choose the mode, and finally set the current – this sequence makes operation easier.

Technical Specifications (Comparison)

Input: DC 5V / 2.0A (Type‑C)
Dimensions: 146 × 100 × 33 mm (same for both)

Charge current (Li‑ion / Ni‑MH):

• M4: 500mA×4 / 1000mA×2

• M4S: 300mA×4 / 500mA×4 / 700mA×2 / 1000mA×2

Discharge current:

• M4: fixed 500mA (only in TEST mode)

• M4S: independent discharge 250mA×4 / 500mA×4; in TEST mode, automatically matched (250mA or 500mA) based on charge current

USB output: 5V / 1000mA (both require a Li‑ion battery in Channel 4)

Compatible batteries (same for both):

• Supported: 18650, 21700 (flat‑top, ≤70mm), 26650, 14500, AA, AAA (only 3.7V Li‑ion & 1.2V Ni‑MH)

• NOT supported: 21700 button‑top/protected, 1.5V Li, 3.2V LiFePO₄, 3.8V IMR

Termination: Smart voltage monitoring (–ΔV & 0ΔV)
Internal resistance test: Not available (all displayed data are for reference only)

Summary

• If you prefer classic, practical, and easy operation, choose the Lii‑M4 (button version) – two modes cover daily charging and capacity testing needs.

• If you want more comprehensive battery management (independent discharge, more current steps, Li‑ion storage) and like the modern touch control experience, choose the Lii‑M4S (touch upgrade).

Both models work perfectly with flat‑top 21700 batteries and provide safe, intelligent charging and testing for your 18650, Ni‑MH, and other compatible batteries. Please strictly follow the battery type restrictions to ensure safe use.