The Victron Energy Buck-Boost DC-DC Converter 25 Amp is the vehicle auxiliary battery charger that delivers a stable, programmable charge to a 12V or 24V service battery from either a 12V or 24V starter system — the definitive fix for smart Euro 5/Euro 6 alternators that can't properly charge auxiliary batteries. Buy online today for $99.89, an exceptional discount off the $685.10 compare-at price.
Programming the Buck-Boost 25A
Charge voltage, current, and profiles are fully programmable through the free, user-friendly VictronConnect PC application. Set lithium or lead-acid profiles, output voltage, and engine-run behavior in minutes.
Why Doesn't VictronConnect Detect My Buck-Boost 25A?
Ensure you're using the VictronConnect desktop app with a VE.Direct USB interface (not the mobile Bluetooth app — this model is not Bluetooth-native). Verify the correct COM port and that the unit is powered; then it will appear under the connected devices list.
What Fuse and Wire Size for the Buck-Boost 25A?
For a 25A output, use appropriately sized cabling for your run length and a fuse at the source battery sized to protect the input cable — consult the installation manual's wiring tables for your voltage configuration and cable length. Always follow applicable electrical codes.
Can It Charge a Lithium Auxiliary Battery?
Yes. Fully programmable charge profiles make it an excellent lithium charger, and it provides alternator charge-current protection for lithium systems in vehicles with Euro 5/6 smart alternators.
Specifications
Product Details
- Brand: Victron Energy
- Model / Series: Buck-Boost DC-DC Converter, 25A
- Product Type: DC-DC battery charger (Power Accessories)
- Output: 25A to a 12V or 24V service/auxiliary battery
- Input: 12V or 24V vehicle systems (one unit for all combinations)
- Features: Engine-running detection to protect the starter battery, full PC programmability
Compatibility & Use Cases
- Campervans, RVs, boats, and service vehicles with Euro 5/6 engines
- Lithium or lead-acid auxiliary batteries (12V or 24V)
- Systems needing alternator charge-current protection
Comparison & Alternatives
Compared to simple isolators or fixed-ratio DC-DC chargers, the Buck-Boost 25A handles both buck and boost conversion in one unit, works with any input/output voltage combination, and prevents starter-battery deep discharge with built-in engine detection.
Price Value & Deal Value
At $99.89 vs. $685.10, you save $585.21 (85% off) — the deepest deal in this batch. Apply coupon OUTPOST12 for an extra 12% at checkout, and free shipping on this order over $45.00.
