⚡ Pillar 01 — electrical & energy
DC-DC (B2B) chargers compared (Victron, Sterling Power, Renogy, BOS)
Charging a leisure battery from the alternator needs a DC-DC (battery-to-battery) charger, not a direct wire — smart alternators make a plain split-charge relay unreliable. Four options, checked against each maker's own spec sheet.
Method
Spec-for-spec
maker's own datasheet/product page
Basis
B2B / DC-DC chargers
checked Jul 2026
Sources
3 / 4 verified
1 line on a provisional source
Independence
No affiliate links
this page carries no monetization
How we compared
Not all four are the same architecture — Victron and Sterling Power are standalone alternator-only B2B boxes; Renogy's DCC50S adds a second, solar MPPT input; BOS's LE300 is a battery-integrated smart-charging system meant to be paralleled, not a single charger box — flagged separately rather than forced into a false like-for-like. Figures are from each maker's own product page or datasheet for the specific model named.
Max output currentCharging inputsIsolationWarranty
The spec-for-spec comparison
| Product | Max output current | Charging inputs | Isolation | Warranty | Source |
|---|---|---|---|---|---|
| Victron Orion-Tr Smart 12/12-30A Isolated Best all-round Bluetooth built-in · VictronConnect app | 30A | Alternator only | Galvanically isolated | 5 yr | verified · 2026-07 ↗ |
| Sterling Power BB1260 marine-grade · 9 preset charge profiles | 60A | Alternator only | Non-isolated (B2B) | n/s | verified · 2026-07 ↗ |
| Renogy DCC50S dual-input · Euro 6 smart-alternator compatible | 50A (25A alternator + 25A solar, combinable) | Alternator + solar MPPT | Non-isolated (VSR-based) | 1 yr | verified · 2026-07 ↗ |
| BOS LE300 smart battery system ⚠️ different architecture — battery-integrated, scales in parallel | 12.5A per unit (5–40°C); up to 50A with 4 units paralleled | Alternator (integrated smart-charging logic) | n/s | n/s | provisional · 2026-07 ↗ |
Verdict — standalone B2B vs solar-combined vs a different architecture For a straightforward alternator-to-leisure-battery upgrade, the Victron Orion-Tr Smart 12/12-30A Isolated is the well-documented default: galvanic isolation, app monitoring and a 5-year warranty. Anyone needing more current from a single box should look at the Sterling Power BB1260's 60A rating, though its published warranty term was not found on the checked page. The Renogy DCC50S is the pick when solar and alternator charging need to combine in one unit, at a shorter stated 1-year warranty. BOS's LE300 is not a like-for-like DC-DC box — it is a smart, alternator-charging battery system designed to be paralleled — so it belongs in this comparison only as a different way to solve the same problem, not a drop-in swap for the other three; several of its published figures (isolation, warranty) could not be confirmed on the checked page.
Sources
What this page is based on — every source is verified and links out so you can check it yourself.
- Verified / official
- Provisional
- Out of date
- Victron Energy — Orion-Tr Smart DC-DC chargers (12/12-30A Isolated, 5-yr warranty)
- Sterling Power — BB1260 battery-to-battery charger (60A, marine grade)
- Renogy — DCC50S dual-input DC-DC charger with MPPT (50A combined, 1-yr warranty)
- BOS — LE300 smart battery system (12.5A continuous per unit, scales to 50A parallel) — different architecture, isolation/warranty not confirmed, provisional