48V BMG Volvo Mount — 12V 3000W Auxiliary Power

48V BMG on a Volvo mount with Scotty AI 3000W for 12V auxiliary power.

About this product

A 48 V motor generator that bolts onto your main engine and makes 7.5 kW continuous, 10 kW peak, straight into a lithium bank, so you do not need a second engine running as a genset.

The BMG takes the second alternator position on a Volvo Penta, D2 to D11, through its Volvo mount, runs on its own belt from the crank and puts 48 V DC straight onto the battery. The inverter that controls it is built onto the back of the machine, and the Scotty AI 3000 in this kit runs it and supplies 3000 W at 12 V from the same bank.

Inside, permanent magnets plus a field winding keep it making power at idle, where a 48 V alternator makes a few hundred watts. Two separate three-phase hairpin windings give smoother power and keep it going on one if the other fails. It is 150 mm across, 155 mm long and weighs 7.3 kg.

Your engine is the genset

A genset is a second engine with its own fuel, exhaust, cooling and servicing, carried only to make electricity. The BMG makes that power from the engine you already run: 7.5 kW continuous and 10 kW peak at 48 V, from a machine 95% smaller and lighter than a traditional genset. Charge while you motor, then run the boat on the bank with the engine off.

No diodes: an inverter built onto the machine

A conventional alternator turns its AC into DC through diodes. The BMG carries its own inverter on its back, switching with automotive-grade AEC-Q101 and AEC-Q200 parts and controlled digitally over CAN. That is how it reaches up to 85% from shaft to battery: 90% in the machine, 94% in the inverter.

Works with

  • Volvo Penta marine engines, D2 to D11 — Volvo mount, in the second alternator position
  • Other engines and vehicles — The same BMG on its own mount for each
  • 48 V lithium with a CAN BMS — Scotty AI reads the BMS and follows its charge limits
  • 48 V lithium without CAN — Charged by voltage, with a wired stop-charge input
  • Victron lithium — Set up as a non-CAN battery; the charging rate is the same
  • Victron Cerbo GX and Ekrano GX — Shown as an alternator, Venus OS 3.63 or later

Specification

Power

Continuous output
7.5 kW
Peak output
10 kW
At engine idle
Over 2 kW
Efficiency
Up to 85%
Machine × inverter
90% × 94%
Output
48 V DC, 40 to 57.9 V

Machine

Type
Permanent-magnet motor generator with hybrid excitation
Stator
Dual three-phase hairpin, the windings 30° apart
Rotor
16 permanent magnets
Inverter
Built onto the back, AEC-Q101/Q200 parts
Size
150 mm diameter, 155 mm long
Measured
Without the shaft and pulley
Weight
7.3 kg
Pulley
Poly-V, overrunning clutch
Cooling
Air, internal fan

Installation

Mount
Volvo mount, Volvo Penta marine engines, D2 to D11
Belt hub load
Under 2000 N
Pulley ratio
Typically close to 3:1, set in Scotty AI
Controller supply
12 V only (KL15 and KL30)
48 V terminals
Two M8 studs, 15 to 19 Nm; no reverse-polarity protection
Control
CAN, from Scotty AI

Environment

Operating temperature
−30 °C to 105 °C
Protection
Inverter IP6K9K (with its connector mated), motor IP25
Temperature sensing
Four points; Scotty AI derates from 120 °C

In this kit

Scotty AI
Scotty AI 3000: 12 V 3000 W auxiliary power
Victron
Appears as an alternator, Venus OS 3.63 or later

Questions

Does it replace my alternator?

No. On a Volvo Penta it takes the second alternator position on the Volvo mount and runs on its own belt, so the factory alternator stays and keeps charging the start battery.

Will it overload a small engine?

Scotty AI works out what the engine can deliver at its RPM and sets the BMG to that. It reads the generator's torque and stops charging immediately if the engine appears overloaded, and when you commission it you set the maximum charge current, starting at about half the final figure.

What happens if the CAN connection is lost?

The BMG carries on in a limp-home mode at up to 4 kW until the connection is restored.

Can I use it with a Victron lithium battery?

Yes. Connect Scotty AI and the BMG to VE.Can and set the battery up as a non-CAN battery: Victron's charge limits are not shared over NMEA 2000, and the charging rate is the same either way.

Do I need a separate DC-DC for 12 V?

No. The Scotty AI 3000 in this kit supplies up to 3000 W to the 12 V side from the 48 V bank. That is double the 1500 W kit.

How is the 48 V side wired?

Straight from the BMG's B+ and B− studs to the 48 V battery, with a Mega fuse on the positive close to the battery. The BMG has no reverse-polarity protection, so check the polarity before you connect it.

SKU
SHSA4804Volvo-3000
Category
48V BMG Alternators
Price
$10708.25 AUD inc. GST
Availability
In stock

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