90A 12V→12V Advanced DC-DC Battery-to-Battery Charger

The DC1212-90 is a high-power, fully automatic 90A DC-DC charger designed for leisure vehicles, boats, and commercial or specialist applications that require fast, safe charging of large 12V battery banks. Using advanced buck-boost power conversion and high-frequency switching technology, this unit delivers consistent output even with fluctuating alternator or supply voltage — ensuring your auxiliary batteries are always charged to optimum levels.

Suitable for Lead Acid, AGM, Gel, LiFePO₄, and Lithium-ion (NCM) batteries, the charger features a smart three-stage charging program for efficient and reliable battery maintenance. With comprehensive protections, temperature-aware charging, and optional data monitoring, it’s ideal for motorhomes, campervans, work vehicles, and marine systems with multiple battery sources.

Key Features

• High-output charging: provides up to 90A of regulated charging power for rapid replenishment of large 12V battery banks.
• Intelligent three-stage charging: fully automatic bulk, absorption, and float modes tailored to each battery chemistry.
• Selectable battery profiles: DIP-switch selection for Lead Acid, AGM, Gel, LiFePO₄, or Lithium-ion (NCM) batteries.
• Safe unattended operation: protection against overload, overheating, over- and under-voltage, short circuit, and reverse discharge.
• Temperature management: supports optional external sensor for voltage compensation on lead-acid batteries and cold-charge protection on lithium types.
• Data monitoring: optional Bluetooth module or remote LCD meter (sold separately) for live status, charging data, and diagnostics.
• Ignition-controlled start/stop: begins charging automatically when vehicle ignition is on and stops when turned off, or can operate via voltage-sensing control.
• Continued charging under load: maintains stable output even while 12V appliances are in use, preventing voltage dips or surges.
• Wake-up function for lithium BMS: automatically re-activates lithium batteries that have entered protection mode.
• Relay control output: provides a signal to link battery banks under heavy load so the source battery can assist with starting or powering large equipment.
• Precision sense terminals: optional sense lines bypass voltage drop in long or heavy-gauge cables for more accurate charging control.
• LED indicators: four status LEDs display charge stage and diagnostic information for clear, at-a-glance monitoring.

Technical Specifications

Compatibility & Installation

Designed for 12V electrical systems only. Works with all major 12V battery chemistries. Not compatible with 24V systems or mixed-voltage setups. For best results, mount in a ventilated area and connect using properly sized cables and fuses. Optional accessories — including Bluetooth module, temperature sensor and remote LCD meter — provide full monitoring and environmental protection in demanding installations.

Documents Available

Installation and user guide available for download.