30A 12V→12V Compact DC-DC Battery-to-Battery Charger
Compact, high-frequency DC-DC charger delivering up to 30A to a 12V auxiliary battery from a 12V starter / source battery. Ideal for campervans, motorhomes, boats and specialist vehicles where fast, safe multi-stage charging of leisure batteries is required during driving or engine-on operation.
Key features
- Intelligent multi-stage charging for lead acid (Flooded/AGM/GEL), LiFePO4 and Lithium-ion (NCM).
- Simple battery-type selection via DIP switches; automatic resume of last setting.
- Supports unattended charging with protection against overload, over-temperature, over/under-voltage, short-circuit and reverse discharge.
- D+ ignition control for automatic start/stop with engine on/off.
- Continues charging while loads are in use; stabilises voltage for sensitive 12V equipment.
- Optional remote LCD meter, Bluetooth module and external temperature sensor.
- Wake-up function for Lithium batteries: when the Battery Management System (BMS) of a lithium battery goes into the protection mode, the charger can automatically activate the BMS and continue charging the lithium battery.
- Source battery voltage control: via the D+ connection, the charger can turn itself on and off based on the source battery voltage. This ensures that charging only occurs when the source battery has sufficient voltage, preventing excessive discharge and protecting the battery from deep cycling damage. This feature is particularly useful in vehicles or marine applications where the alternator or solar power may not always provide a consistent supply of energy.
Technical specifications
| Source battery voltage | 12V |
| Input voltage range | 10.5 - 16V |
| Effective D+ signal range | 8 - 16V |
| Max charging current (target) | 30A |
| Max charging power | ≈390W |
| Target battery operating voltage range | 8-16V |
| Recommended source battery | ≥60Ah |
| Target battery types | Lead acid (Flooded/AGM/GEL), LiFePO4, Lithium-ion (NCM) |
| Target battery capacity | 45–280Ah |
| Bulk voltage | AGM 14.7V, GEL 14.3V, Flooded 14.4V, LiFePO4 14.4V, Li-ion 12.6V |
| Float voltage | AGM 13.5V, GEL 13.8V, Flooded 13.5V, LiFePO4 13.8V, Li-ion 12.5V |
| Temperature compensation | -3mV/°C/2V (lead-acid) |
| Operating temperature | -20°C to +50°C |
| Self-consumption | ≈17mA |
| Dimensions (L×W×H) | 147 × 142 × 41 mm |
| Weight | ≈0.46 kg |
| Warranty | 1 year |
Compatibility & installation
Designed for 12V systems only. Not suitable for 24V systems or mixed 12V/24V banks. Use appropriately sized cabling and protection. D+ input recommended for ignition-controlled start/stop.
Optional accessories
- Remote temperature sensor (for advanced temperature compensation and lithium low-temp charge inhibit).
- Bluetooth module (view parameters and status via mobile app).
- Remote LCD meter.
Documents available
Installation & user guide available to download.