CAN Controlled Alternator Charging Optimized for Engine

600% increase in Vehicle Charging

Consider a standard factory alternator for Toyota 70 & 200 Series: (photo on right is a used alternator taken from 70 series. 200 series is same unit)

  • Rated at 130A output at 6,000 RPM. See Charts below.
  • When cruising at 100kph in a Diesel, the max power available from the alternator will be in the range of 130-150A depending on age and temperature.
  • However, with a typical DC to DC fitted, in an hour of driving, this alternator can only deliver 30Ah.



Photo on right is the SAFIERY High Performance model specifically designed by Rapid Power in Brisbane Australia. 

1.   Increase the raw output with this high performance alternator

  • With an efficiency approaching 85%, upgrade to this High Performance Alternator with a 250A rating. High output is achieved with:
    • Interlaced magnetic leaves added to rotor.
    • 10mm stud for power connection.
    • Field control plug in addition to standard plug to suit Toyota.
    • Optimized capacitor control to minimize DC ripple at this power.

Cruising at 100kph will give 250~270A available output.
Subtract the 75A for vehicle loads and 180A is available for charging batteries.

2.   Upgrade from an Analog DC to DC Converter to a Digital CANbus Controller

  • DC to DC Converters operate around 85-87% efficiency.

  • They generate a lot of heat.
  • Adding 3 of these in parallel from Victron will increase the output by 250% after taking into account efficiency losses. However, at idle, demanding 90A from the Alternator may cause it to overheat as the cooling fan speed is low.
  • This is the problem with analog control. It is a “one size of output for all conditions”. To protect the Alternators, DC charging has to be limited. The user then misses out gaining the high power output at cruising speeds.

Digital CANbus controllers do not convert power, they control it.

  • They are effectively 100% efficient.
  • They change the performance of the alternator to deliver the maximum power to charge the batteries whilst monitoring the alternator and vehicle engine.
  • They scale the power to maximum. In this case a comfortable 600% increase.
  • They are perfect with Lithium batteries taking them to 100% SOC.
  • Can be used with AGM, but remember AGM charging efficiency is very poor once over 80% SOC.
  • They can be mounted in the engine bay.
  • They are rugged and compact- only 190 x 100 x 60 mm

Triple battery charging

If you have a second AGM battery in the engine bay and a lithium in the rear, this Digital CANbus controller is perfect for your application.

  • No other DC to DC is required.
  • A Victron ARGOFET 200A Charging Splitter is added with ignition switched activation. This directs the charging to both the second battery in the engine bay and the Lithium battery in the rear. When the ignition is turned off, the device isolates all batteries from each other.

  • Lithium is given priority to charge first, then the AGM in engine bay, at the same time a small percentage of power is directed to the starter battery.
  • This complex arrangement of 3 batteries and mixed chemistries is easily managed.

3.   Purchase Lithium battery(s) that will accept 180A of charge if you don’t have one.

Quality Lithium batteries are required. Lithium batteries are sensitive to poor charging profiles. With the significant amount of charge applied, it is important that the lithium battery(s) can accept the charge. The CANbus controller can be programmed to limit the maximum charge, however this limits the technology and a DC to DC converter may be best investment.

4.   Optional Smartphone App Display

If you dont have a method for monitoring the Vehicle Charging, then we have a slick option for you. By upgrading from a standard Shunt to a Smart Shunt, you will see on your smartphone:

  • Charging Power in Watts.
  • Battery Voltage being Charged.
  • Alternator temperature.
  • Charging History in kWh.
  • Min/Max Battery Voltage.
  • MinMax Alternator Voltage.

CANbus Alternator Charging Lithium Batteries


FAQ on the CANbus Controller:

How affordable is this?

Very affordable. The CANbus controller is a similar price to the published price by REDARC of their award winning BCDC1250D:  a 12V 50A In-vehicle DC to DC battery charger. However, the CANbus controller can deliver 300%+ performance compared to this REDARC model. In addition, if you have a second AGM in the engine bay, then the savings are significant as Dual DC to DC converters are not required.

The optional Smart Shunt and Smartphone App is additional price. This is the only App dedicated to Alternator Charging with Alternator temperature as well as Power, Voltage and history in the market.

What Voltages can be used with the CANbus Controller?

12V, 24V and 48V. However, there is no step up or step down in voltage range.

Can it be used with Mercedes Sprinter?

Definitely. We specialize in Sprinters and have a alternator that mounts underneath the Sprinter on a factory mount that produces 5kW at 48V. This charges the 48-12V hybrid Safiery system in the sprinter. It is more powerful at idle than a 2kW portable generator. It can also be easily installed in VW Crafter, Ford Transit Van and several other vehicles.

What happens with vehicles that have a Smart CANbus chip in the Alternator?

It is common to see a smart chip in the alternator with ECU CAN control. We have a proprietary way of working with this so no ECU engine alert occurs for most manufacturers. The list of models available is shown in our on-line store.

What if I already have a high output Alternator?

Then you just need to purchase the CANbus controller. It will be important that the high output alternator has the necessary terminals easily available.

How easy is it to fit?

We ship the product to you pre-configured for your vehicle and lithium battery type. There are thirteen wires to connect on the plug in harness that we provide. Typical installation time in less than an hour for the controller. Adding a large gauge power cable may take longer. An added cable support bracket is provided so the size and style of these large cables does not damage the alternator off-road.

When was this developed?

Alternator controllers have been around for some time. However, higher charging demands from the marine industry, particularly with lithium batteries, could not be met with these controllers. A controller was released to the USA marine market in 2018 with a 300A+ capacity and since developed further by a specialist team with 15+ years of Alternator charging experience. Safiery contributed their deep Lithium charging know how. The result is a CANbus controller that connects to both Lithium battery(s) and vehicle CANbus for the RV market.

Will it work with any brand of Lithium battery?

Yes it can. The battery charging parameters especially at low temperatures has to be fully understood. With Safiery lithium, we have this modelled. For other batteries, the data needs to be supplied by the user.

Whay is it called CANbus?

With Safiery CANbus lithium batteries, the battery SOC and charging level parameters and temperature is transferred using CANbus. It is so simple. No optimization module is required.

Will it work with AGM batteries?

Yes it can using bulk, absorption and float voltage charging. However, as lead-acid chemistry reduces the charge acceptance rate when the batteries are around 80% SOC , charging efficiency drops by more than 50%. In short it may be a waste to invest in this technology and still have AGM batteries.

Alternator is on full output and lithium stops accepting charge?

This is a major problem in the marine industry with high charging alternators. When the charging circuit is suddenly disconnected, the instantaneous power of the alternator has to be absorbed. This power can flow back and destroy the alternator. This is managed by the CANbus controller with precise battery voltage and current. If the lithium battery is also being charged by solar while driving, and the lithium rises to a full state of charge quickly, the CANbus controller will feather back the alternator power as 100% SOC is reached. There is no damage to the alternator. In the unlikely event of a sudden disconnect, the CANbus controller energises the ARGOFT device.

Some may call this a big step forward for vehicle charging?

It’s the biggest step forward we have seen since the advent of the DC to DC more than 25 years ago. It is the perfect match for Lithium systems.

  • Perfect solar backup in poor weather.
  • Perfect primary charging source when there is not enough roof space for solar.
  • Perfect for special vehicles with up to 5kW Inverters on board.
  • Perfect genset replacement for Marine market with medium to large alternators.

Can we adjust the settings?

Inside the unit, there are a series of dip switches that enable you to change settings for battery type and size. This is a CANbus controllers and Safiery can adjust up to 100 parameters for special applications. Once changed, the firmware is not affected by power off.

Are there other Optimization Modules to suit alternative vehicles?

We are starting with the Optimization Modules to suit Toyota and to suit Mercedes Benz Sprinters as these are dominant brands in their class. This is a software mobule pre-loaded to suit the output parameters to suit a 70 series and 200 series.

We will release modules for other brands in the future.

What can we see on the Victron Display

The Power Generated by the Alternator is displayed in Watts.

The Alternator Master Power Isolator can be turned on/off from the Victron Touch Display.


After camping overnight and driving till midday to next campsite, a CAN Controlled alternator will be a primary source of power. The energy delivered in a 1-3 hour drive will replenish most systems.


After finding the perfect campsite, a CAN Conrolled alternator will be a backup source of power. In poor weather, or if touring southern Victoria or tasmania, back-up power is essential. 
With 90A of alternator power available, a depleted 200Ah Lithium will take just over 2 hours to fully replenish. Selected 12V alternators produce 70A at idle. Just idling the engine is now a viable backup to solar as a primary power source in poor weather.

What is the Wiring?

In addition to the Wiring Loom provided above:

From the factory Alternator: run an appropriately sized wire from the Starter Battery positive to either:

1.     With a second battery in the engine bay:  to the ARGOFET “in”.

2.     From one of the the “out” to the engine bay AGM positive

3.     From the other “out” to the Lithium battery positive in the rear.

4.     Connect the ‘energise” input to an ignition “on” circuit.

5.     With no second battery, then use either a single “out” ARGOFET or a Smart Battery Protect if you have no other isolation.

6.     Remember there will be up to 200A on this circuit so robust switching devices are required. We ONLY recommend Victron FET based devices.

The negatives are common.

From the Alternator Plug, connect the 4 pin outlets in parallel to the Alternator CAN-bus controller. Cables as marked. Wiring harness is provide to the CAN-bus Controller.

Connect a 12V set of Pos/Neg cables to CAN-bus controller. Max 4mm.

That’s it for the standard module.

Optimization Modules may also require a second CAN connection to the vehicles ECU Electric CAN Module.

CAN Controller matched to Alternator Choices:
4WD to suit Toyota and other brands, Trucks, Marine, Large Vehicles.




Small Engine(s)

Large Engine(s)


12V, 24V, 48V

12V, 24V, 48V

12V, 24V, 48V



70A to 270A

12V to 200A
24V: to 200A
48V: 100A

12V to 200A
24V: to 200A
48V: 100A

Double 10kW (20kw total)

Engine Optimization



Power curve of alternator matched to Engine

Power curve of alternator matched to Engine

Engine Optimization to Suit Toyota

Optimization Module to Suit Toyota 

With this module the controller is pre-programmed to suit the factory or aftermarket alternator. The alternator is loaded externally by changing the voltage and current on the Field Control terminal of the Alternator. This is increased until there is a slight voltage drop because of vehicle loads. The power demand on the alternator is then “turned down” to allow more power to the vehicle.  It is of course an aftermarket product not related to Toyota or the Landcruiser brands.

Specially to suit Mercedes Sprinter

Using Mecedes Sprinter MBUX 7in or 10in Display

With Mercedes Sprinter, a 48V second alternator is recommended. The Safiery 48-12V hybrid system will be replenished with up to 5kW from alternator. Safiery have developed an interface to the Maercedes Sprinter MBUX. With this module the alternator power (as well as the whole energy/power system) is displayed on the standard mercedes Sprinter MBUX display. This module provides a touch display feature for turning the second alternator off during water crossings.  The module is integrated into the standard Mercedes Steering controls and appears as if a "factory" fitted item. It is of course an aftermarket product not related to Mercedes Benz or the Sprinter brands.

Power output at Idle (estimate)

360W Min
2.5kW Max

360W Min
​2.5kW Max

1.5kW Min
​3.5kW Max

4kW Min
​5kW Max

Max Energy delivered typically in 3 hours engine operation





It is far more convenient and economical to run a CAN Conrolled 5kW alternator for 1 hour than a Honda EU20 (2kW) for 2-3 hours to produce a similar result.

Solar Backup Power


Using Honda 2000W Generator

Using Safiery 5kW Alternator



Diesel (Engine fuel)


35kgs plus Petrol 20kgs



Smell and safety of carrying petrol

Turn the key

Power to batteries when running

Assumng battery charger is 1.5kVA then Honda should produce that power but not on eco-thottle.

At idlle, 2.5kW direct to batteries

Hours to Replenish 800Ah (12V equivalent) of Lithium (assuming air-conditioner run off battery while in camp.)

6.5 hours

3.8 hours

Hours Driving to replenish the same amount.

With 840W DC to DC from Alternator then > 12 hours

Less then 2 hours