48V - 12V Hybrid Systems

48-12V Hybrid Systems

If the continuous current is greater than 100 Amp, then there is potentially a lot of power loss. There is not only power loss but heat. Heat expands connections, then cold contracts and maintenance issues follow. Lower currents lead to less maintenance and more reliable systems.

Lower current and higher voltage also reduces costs significantly. The higher the current (measured in Amps), the bigger the cable and components have to be.

The weight and cost of large cables plus the on-going maintenance is shown in the table below.

 

Cables

12V

48V

Saving

Current

120A

30A

 

Cable Size

35mm2

6mm2

 

Cable weight

30kg

0.5kg

80% Lower

Voltage Drop

6%

2.2%

2.5%
acceptable

Energy Loss

84W

33W

60% Lower

Cabling Cost

$95.00

$29.00

70% Lower

Fuses and Lugs

$18.60

$3.50

85% Lower

12 Volt used to be a standard without an Inverter. Today, inverters are common because:

Significantly lower cost of 240V appliances compared to 12V offsets cost of Inverter,

Fridge

12V

240V

Saving

Model

Evakool

Haier

 

Size

210 L

221 L

5% Bigger

Dimensions

1428 x 590 x 585

1420 x 540 x 595

10%
Narrower

Energy
Per 24 hours

800-900W

805W

Similar

Price

$2,299

$348

85% Lower

Significantly lower cost of the core components making 240V power very affordable.

Retail Prices

12V

48V

Saving

1200W
Solar
Controller

$1,117

$273

75% Lower

2.4kWh
Lithium Battery

$2,990

$2,200

36% Lower

3000W
Inverter/Charger

$2,550

$1,860

36% Lower

High efficiency and speed of Induction cooktops makes them more practical for 4WD’s and RV’s.

Longer Cycle life and warranty of Lithium batteries makes energy storage affordable.

Compact, efficient 240V appliances and Lithium batteries have opened up new possibilities

Lithium Batteries: 48V is 25% the cost per warranted cycle compared to 12V

200Ah 12V Lithium battery: $3000, 28kgs, 3 year, 2,000 cycle warranty. $1.50/Cycle

Equivalent 48V Lithium battery: $2,200, 22 kgs,  5 year, 6,000 cycle warranty. $0.37 /Cycle.

Hybrid Operation

Get the best of both worlds, operate Inverter and Lithium battery system at 48V,

Run LED Lighting, low power pumps and even fridges at 12V fed from 48V system.

Operation with Buck Boost

This is easy to do with the 3,000W Buck Boost. The power flows both ways. When the Alternator is apply power on the 12V side, the power flows through to charge the 48V battery. At the same time 12V power is taken for the 12V devices like fridge and lights.

When the alternator is not running, the Buck Boost reverse direction (in less than 25ms) and supplies power on the 12V side.

Read About Regenerative Braking and why traditional DC to DC will have a problem in future compliance:

Operation with 48V Alternator

A 48-12V converter is used to drop power down from the 48V level to 12V. These are simple and in expensive as they are not battery chargers. The output voltage can be adjusted.

Replenishment from Alternator

This is another big benefit of 48V. Massive alternator power. At 12V, either from a factory aternator at better than 150A or an aftermarket 12V alternator at 250A. The 12V source power is directed through the 3kW Buck boost which will take up to 250A at 12V and output 48V at 60A.

With a 48V secondary alternator, you can easily capture directly 100A, that is 5,000W of power.

CANbus Control

Safiery 48V Lithium batteries may have a BMS that communicates with CANbus. There are several advantages:

  • No Shunts are required as the current measurement using hall effect sensors is in the battery itself.
  • An accurate voltage, current and temperature measurement can be transmitted by CANbus - there is no loss
  • A pre-warning of BMS action to "stop charge" can be issued by CANbus

Safiery links CANbus Lithium batteries with the 1) Buck Boost, 2)Alternator controller and the 3) Victron GX operating system. It is a simple and elegant system that is all digital. The design is modelled on a vehicle's CANbus system.

Max 240V Power Using 48-12V Hybrid

Examples of 48-12V Hybrid

“Simplicity is at the very heart of this system”

Use your alternator as a power station for your caravan or camper trailer “plug in and run 240V”.