Sterling Power 12-Volt to 48-Volt DC-DC Charger with Jump Start Assistance


  • 12-volt to 48-volt battery to battery charger (DC-DC charger) that enables you to charge a 48-volt battery bank from a 12-volt vehicle battery.
  • Charges your hour battery bank at up to 1,500 watts!
    • Input: 9-16 volts, 115 amps
    • Output: 26 amps at nominal 48-volt
  • Bi-directional design enables up to 40 amps of charging from the house battery bank to the vehicle battery for maintaining the vehicle battery (see details in the description below).
  • Buck Boost design, offering high efficiency (95-98%)
  • By default, the unit will charge at 100% of it’s charging current capability but you can adjust the charging current down between 85% to 65%.
  • Smart Alternator/Euro 6+ compatible
  • The unit can be turned on with either an ignition-switched trigger wire or “vibration sense” mode.
  • 6x preset battery type charging profiles.
  • Great complement or backup to a 48-volt secondary alternator power system if your battery bank can accept the additional charging current.
  • Optional remote panel available separately.

$20 flat-rate shipping to the continental USA!

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The BB1248120 is able to charge in both directions – from the vehicle battery to the house battery bank as well as from the house battery bank back to the vehicle battery. As long as the house battery bank is over 13.2V (13.5V if lithium) and the vehicle battery is below 13V the battery to battery charger will allow approximately half current (~20A) to flow back to the vehicle battery up to about 13.4V (float voltage). This unique feature allows the vehicle/starter battery to remain topped up when there is surplus energy in the house battery bank. Best of all, this feature will NOT drain your house battery bank. Instead, it only uses surplus power. Once your alternator / engine turns the unit will revert to normal charging of the hosue battery bank. This mode can be disabled, but is on as default.

Self recovering protections:

  1. Under voltage protection
  2. Input over voltage protection
  3. Output over voltage protection
  4. Over current protection
  5. Charge over temperature

Other specifications:

Operational temperature: -20 deg C -> 60 deg C
Cooling method: thermostatically controlled
Fan: variable low speed
Dimensions: 10.6″ x 5.1″ x 2.9″ (270mm x 130mm x 73mm)
Weight: 4lbs (1.8Kg)
Optional Remote control available

PDF Manual

Additional information

Weight 200 oz
Dimensions 24 × 24 × 24 in