-Compatible with multiple battery types. -All-round electronic protections for ultra safety. -Compact and robust design with CE certification. -Smart 3-stage charging: bulk, boost, and float. -Protect your starter battery. The 40A DC to DC Battery Charger is the most effective way to charge your house/secondary batteries from the starter battery. Compatible with a multitude of alternator types, the DC-DC battery charger offers correct charging for AGM, Flooded, Gel, and even Lithium deep cycle batteries! Featuring a 3-stage battery charger and multiple electronic protections, users can feel confident that their batteries are being charged optimally and automatically. For additional safety, it isolates the input from the output preventing incorrect voltage transmission. Easily install the compact yet sturdy DC-DC battery charger on RV's, commercial vehicles, boats, yachts, and many more applications! Click here to know more about the inverter of the 2nd bundle option: Renogy 2000W 12V to 230V/240V Pure Sine Wave Inverter (with UPS Function)! If you have any questions regarding this product, please submit a case ! Empower Your Journey on the Go Maximize charging efficiency on the go with enhanced versatility. Universal Compatibility Comprehensive Protections Compatible with Multiple Battery Types The DC-DC battery charger is highly compatible with AGM, Flooded, Gel, and Lithium batteries, ensuring optimal performance for various battery types. Seamless Charging, Ultimate Safety Isolated input/output with multifunctional safety technology for error-free and secure house battery charging. Protect Your Starter Battery Renogy's DC-DC battery charger works seamlessly with traditional and smart alternators. The included D+ Ignition cable identifies generator starts, safeguarding the starting battery from over-discharge and protecting the generator. (Recommended: 18-16AWG copper cable. D+ Ignition Cable not included.) Smart Charging Protection The DC-DC battery charger's LC wire automatically adjusts the charging current, safeguarding the house battery from potential damage due to excessive charging. (Recommended: 18-16AWG copper cable. LC cable not included.) Smart 3-Stage Charging Efficiently charge your house batteries from the starter battery with Bulk, Boost, and Float stages, ensuring automatic and optimal charging up to 100%. Prolong Battery Lifespan Automatically adapts charging modes to match battery voltages, while the temperature sensor provides -3mV/°C/2V compensation, ensuring optimal charging in varying temperatures. (Please note that the temperature sensor is not included. If the lithium battery has a built-in BMS, an external temperature sensor is unnecessary.) Explore the Complete Connection The Renogy Difference Explore the Complete Connection Going solar is not that complicated. Renogy is here to help you build your system faster so you can roam further. The Renogy Difference Going solar is not that complicated. Renogy is here to help...