12V 20A DC-DC Battery Charger for RV, Van, Boat, Off-Grid | Lithium & Lead-Acid Batteries

Features 20A DC-DC Charging: Delivers up to 20A charging current from a 12V vehicle electrical system to the auxiliary battery. Multi-Battery Ready: Compatible with 12V AGM, Flooded, Gel, and Lithium batteries with selectable charging modes. Smart & Traditional Alternator Compatible: Works with both smart and conventional alternators for reliable charging. 2-Stage & 3-Stage Charging: Uses 2-stage charging for lithium and 3-stage charging for lead-acid batteries to maximize charging performance. Battery Isolation Protection: Prevents reverse current between the starter and auxiliary batteries. Comprehensive Circuit Protection: Protects against over-voltage, over-temperature, and reverse polarity. D+ Ignition Control: Charges only when the engine is running to help protect the starter battery. Temperature-Adaptive Charging: Supports an optional RJ11 temperature sensor for automatic charging compensation on lead-acid batteries. Specifications Input Nominal Input Voltage: 12V DC Operating Voltage Range: 10–16V DC Input current limiting: ≤34A Output Rated Output Power: 250W Rated Output Current: 20A Operating Current Range: 18–22A Battery Compatibility: AGM, Flooded, Gel, Sealed, LiFePO₄ (LFP), Lithium-ion General Charging Mode: 2-Stage (Lithium) / 3-Stage (Lead-Acid) Peak Efficiency: 85% (@14V DC, 30% Load) Net Weight: 4.0 lb Dimensions: 8.4 × 7.4 × 3.1 in Certifications: CE, RoHS Package Dimensions: 11 × 9 × 5 in Gross Weight: 5 lb Sold on W SOLAR (https://wsolar.com/products/12v-20a-dc-dc-battery-charger). The price shown is the retail price on that storefront on 2026-10-27, not a GreenB2B quote or a wholesale price.