Tiny 12V 3A DC Voltage Converter Module with low voltage cutoff (for Power-Tool Batteries)

-Free Delivery Australia wide-

A very compact, high-efficiency 12V voltage converter with battery protection, designed to run your 12V gear directly from power-tool batteries  18-22v. Use inline between your battery and the load to power fans, lights, radios, routers, comms gear, etc without frying them. Delivers up to 36W with built-in protections, low ripple, and common connectors for workshop and field use.

Key features

• Wide input for common tool packs: 18v-22v
• Stable 12.0v output up to 3.0 A continuous (36 W), peak headroom for transients
• High efficiency 95% to stretch battery runtime
• Low ripple output for sensitive electronics
• Full protection suite: over current, low voltage cutoff (input), over voltage (output), short circuit
• Rugged build: conformal-coated circuitry
• Compact footprint: 34mm(W) x 19mm(L) x 13mm(H) for easy  mounting inside battery adapters or enclosures
• Fused & colour coded input & output

Electrical specifications (typical)

• Input voltage (Vin): 18–22v
• Output voltage (Vout): 12.0 V ±0.4v depending on wiring length and size
• Output current (Iout): 0–3.0 A continuous
• Output power: up to 36 W continuous
• Efficiency: up to 95%
• Switching frequency: 500 kHz
• Line/Load regulation: ≤±0.5% / ≤±1.0% (typ.)
• Protection thresholds:
  • OCP/limiting: folds back near 3.2–3.6 A (typ.)
  • LVC/LVD: ~16v ±0.5v switches off 17.5v ±1v switches on, to protect battery packs
  • OVP: limits output voltage
  • OTP: auto-recover after cooldown
• EMI: Suitable for most DC loads; add ferrite/bead if powering RF gear

Mechanical & environmental

• unit size (approx.): 34mm(W) x 19mm(L) x 13mm(H)
• Weight: ~12–15g
• Connectors: JST-XH (2.54)
• Operating air temp: −20 °C to +60 °C ambient (free-air); derate above 3A without forced airflow
• Storage temp: −40 °C to +85 °C
• Ingress: Partially sealed for dust protection

Typical use cases

• 12 V fans/blowers mods
• LED lighting (strips/panels up to ~30–36 W)
• Routers, radios, CCTV, small 12v tv’s and monitors, small pumps, instruments
• Field service power from tool batteries when 12 V is required
• Diy Projects

Wiring, installation & use

1. Colour coded connectors and wires, Blue connector is voltage output, Red connector is voltage input, red wire is positive, black wire is negative
2. Observe polarity: VIN+ / VIN- from battery → module → VOUT+ / VOUT- to load.
3. Keep leads short as possible to prevent voltage drop
4. For >2 A continuous, mount supplied stick-on heatsink to the main exposed metal pad on the bottom
5. For RF/noise-sensitive gear, add a ferrite bead on VOUT and ensure good grounding.
6. Remove/disconnect Battery when not in use for more than 12 hours
7. Switch off output side when changing batteries unless the battery is fully charged as an initial load greater than 1A will cause the input under voltage protection circuit to not cut in under 18.5v (fully charged “18v” battery is 21v)

Safety & notes

• Not a charger. Do not connect to battery charge ports.
• this module like all stepdown converters produces heat so be careful when handling, typically runs 20 degrees above ambient under full load 
• Do not exceed 22v Vin (5s Li-ion fully charged ≈ 20.5–21.0v 
• Short-circuit protected, but repeated shorts can trigger thermal shutdown—allow cooldown.
• If mounting inside enclosed adapters, ensure ventilation or derate current accordingly.
• it is recommended to install the supplied extra heatsink to the metal pad on the bottom if running constant loads over 2 amps