DC to DC Battery Chargers & Converters

Charge the House Bank from the Engine—Without Overworking the Alternator

In an RV, van, or boat, the starting system and the house bank rarely share the same job—or the same chemistry. A DC to DC charger sits between them, takes power only while the engine is running, and turns that raw alternator output into a controlled, multi-stage charge the house batteries can actually use. The starter battery stays ready to crank. The house bank—lithium, AGM, gel, or flooded—gets the profile it needs instead of a compromise voltage that undercharges one chemistry and stresses the other.

These chargers also limit how hard they pull from the alternator. That current limit keeps the charging system from overheating the charging system when the house batteries are heavily discharged. Drive, charge, shut down, and step off with a house bank that is actually full.

Give Every House Bank the Charge Curve It Deserves

A lead-acid starter battery and a LiFePO4 house bank do not want the same voltage. DC to DC chargers solve that mismatch. Select the chemistry, set the current, and let the unit manage bulk, absorption, and float so the house pack reaches a true full charge while you travel.

• Chemistry-Correct Charging – Feed lithium, AGM, gel, or flooded house batteries the profile they need from a conventional charging system.
• Engine-On Charging Only – Pull from the chassis side only while the engine runs so the cranking battery is never drained.
• Alternator Protection – Limit charge current so the charging system works hard enough to fill the house bank—and not so hard it overheats.

Convert Power 12 to 12, 12 to 24, or 24 to 12

House voltage does not have to match the starting system. Charge a 12V house bank from a 12V chassis, step 12V up to a 24V house bank, or step a 24V starting system down to a 12V house bank. Outputs from 15A to 60A let you size the charger to alternator size and bank capacity. We even have a Rich Solar 50A unit that also harvests solar through a built-in MPPT controller so the house bank charges on the road and at camp.

• Same-Voltage Charging – Keep 12V-to-12V or 24V-to-24V systems simple while still delivering a proper multi-stage charge.
• Step-Up and Step-Down Paths – Raise 12V to 24V or drop 24V to 12V when the house bank and starting system do not match.
• 15A to 60A Output – Match charge current to a weekend trailer, a full-time coach, or a commercial boat.

Build Dual-Battery Systems That Survive Daily Use

Direct-connect isolators and simple relays dump whatever the alternator happens to make. A DC to DC charger shapes that energy, protects both batteries, and keeps expensive lithium BMS units from rejecting a sloppy charge. The result is a house bank that lasts longer, a starter that still cranks on cold mornings, and an alternator that stays within a safe workload.

Need 12V Accessories on a Higher-Voltage Pack?

Compact step-down converters in this category turn 24V, 36V, or 48V packs into a regulated 12V feed for lights, radios, and small accessories on golf carts and similar equipment. Use those reducers when you only need accessory power—not a second battery to charge. For RV and marine house banks, stay with a DC to DC charger.

Shop DC to DC Chargers for RVs, Vans, and Boats

Choose the voltage path and amperage that match your starting system and house bank, then put a proper charge on the house batteries every time the engine runs. Explore the full range of DC to DC chargers and add the unit that fits your systems and your charging needs.