Sterling Power
Sterling Power BB12120 – 12V 120A DC-DC Battery Charger
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The Sterling Power BB12120 is the flagship of the Saturn series — a 12V-to-12V battery-to-battery (DC-DC) charger that delivers up to 110A at 14.4V of multi-stage charging to your auxiliary bank while protecting your alternator and starter battery. Built for large lithium systems in vans, expedition campers, and overland rigs, it turns your engine's alternator into a fast, intelligent charging source.
Unlike a simple voltage-sensitive relay, the Saturn charger measures both current and voltage and decides intelligently when to move from bulk to absorption to float, so your batteries get a correct, complete charge on every drive. Six preset profiles (Lead, AGM, and Lithium — two of each) plus fully custom profiles via the optional BBR remote let it charge virtually any chemistry correctly.
Charging Specifications
| Type | 12V → 12V battery-to-battery (DC-DC) charger, Saturn series |
|---|---|
| Input voltage range | 9–16V |
| Max output current | 110A at 14.4V |
| Max output power | ~1,584W |
| Max input current | 120A |
| Efficiency | 92–94% |
| Reverse / jump-start current | Up to 40A |
| Battery profiles | Lead I/II, AGM I/II, Lithium I/II (6 presets) + custom via BBR remote |
| Temperature sensor | TEMP1 included |
| Cooling | Thermostatically controlled, variable-speed fan |
| Protections | Self-recovering: under-voltage, input & output over-voltage, over-current, over-temperature |
| Recommended input cable / fuse | 35mm² (2AWG) / 150A |
| Recommended output cable / fuse | 35mm² (2AWG) / 150A |
| Dimensions | 270 × 130 × 73 mm |
| Weight | 1.8 kg |
| Operating temperature | −20°C to 60°C |
| Certifications | CE, UKCA |
| Warranty | 5-year return-to-factory |
Key Features
- Up to 110A output at 14.4V — one of the highest-capacity single-unit DC-DC chargers available
- Bidirectional reverse-charge (jump-start assist) of up to 40A back to the starter battery
- Six battery profiles plus custom charge profiles via the optional BBR remote
- Lithium-safe: a live output voltage wakes most BMS units; charging is disabled below 0°C when the temp sensor is fitted
- Included TEMP1 temperature sensor for lead/AGM voltage compensation
- Self-recovering protections and conformal-coated internals; CE/UKCA approved; 5-year warranty
Smart Alternator / Euro-6 Ready
Three engagement modes cover any vehicle: automatic voltage sense (turns on above 13.5V input), ignition-feed control (for smart/Euro-6 alternators), and vibration sense (begins charging after detecting engine vibration — no ignition wire required).
Installation Notes
Requires a common, direct negative between the starter battery, charger, and auxiliary bank. The positive input must come from a circuit with a starter battery or Alternator Linearisation Device — not straight off a bare alternator. Rate the charger to no more than ~80% of your alternator's output. Fuse both input and output; recommended cable is 35mm² (2AWG) with 150A fusing for runs under 3m.
Presented by Overland Kitted
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