HiTech DC-DC Charger, 40A

HiTech DC-DC Charger 40A – Charge Your House Battery While You Drive

A DC-DC charger (also called a battery-to-battery charger) lets you charge your caravan's house battery from your tow vehicle's alternator while you drive — without overloading the alternator or upsetting the smart charging systems fitted to most modern vehicles.

At 40A, the HiTech DC-DC charger delivers a meaningful charge to your house battery during a typical day's driving, complementing your solar setup and reducing dependence on shore power. It runs a correct multi-stage charging profile for both lithium and lead-acid battery banks, and its sealed housing is built to handle life under a caravan chassis.

Key Features

• 40A Output – a solid charge rate for house battery banks from 120Ah up to 1200Ah
• Safe for Smart Alternators – isolates the house battery load from the vehicle alternator, so there's no risk to modern Euro-standard vehicles
• Lithium & Lead-Acid Compatible – selectable multi-stage charging profiles for LiFePO4, AGM, gel, lead-acid and calcium batteries
• Dual Input – accepts both a battery/alternator input (12.4–16.0V) and a solar input (16.0–25.0V)
• Sealed, Rugged Design – dust- and moisture-resistant housing suited to under-vehicle or under-caravan mounting
• Complements Solar – charges from the alternator while driving, solar handles camp — the best of both worlds

Brand Quality – built to the same standard as the wider HiTech electrical range, this DC-DC charger is backed by the manufacturer's 2-year warranty.

Brand: HiTech Power Solutions

Type: DC-DC (battery-to-battery) charger

Rated Output Current: 40A

Battery/Alternator Input Voltage: 12.4V – 16.0V DC

Solar Input Voltage: 16.0V – 25.0V DC

Output Voltage Range: 13.5V – 15.0V DC

Supported Battery Bank Size: 120Ah – 1200Ah

Battery Types: Lithium (LiFePO4), AGM, Gel, Lead-Acid and Calcium (selectable charge profile)

Charging Stages: Multi-stage bulk, absorption and float, with automatic equalisation

Protection: Sealed dust- and moisture-resistant housing, soft-start, overcharge protection

Application: Vehicle alternator to caravan/motorhome house battery charging

Weight: 0.6kg

Dimensions: 200 x 130 x 60mm

Warranty: 2 years manufacturer's warranty

Do I need a DC-DC charger if I already have solar?
Solar only charges your battery when the sun is shining. On overcast days, in winter, or when you're spending multiple days without much sun, a DC-DC charger ensures your house battery gets a meaningful charge every time you drive. The combination of solar and DC-DC charging is the most robust off-grid setup.

Won't a direct cable from the vehicle battery charge the house battery?
A direct cable (ignition-controlled relay) will transfer voltage from vehicle to house battery, but it can upset modern Euro 6/Euro 6d smart alternators that reduce output when a load is removed — they don't tolerate a direct battery load well. A DC-DC charger presents a stable, controlled load that's safe across all vehicle types.

Will it charge my lithium battery correctly?
Yes. The charger's selectable charge profiles include a dedicated LiFePO4 setting alongside AGM, gel, lead-acid and calcium profiles, so your battery receives the correct multi-stage charge for its chemistry.

Does the price include GST?
Yes, all prices shown on the site include GST.

Do you ship NZ-wide?
Yes, we ship throughout New Zealand.

How do I know this will suit my setup?
Check the specifications above against your battery bank size and chemistry, and your vehicle's alternator type. If you're at all unsure, contact us with your setup details and we'll help confirm it's the right charger for you.

What's the warranty?
This DC-DC charger is covered by the manufacturer's 2-year warranty.