Mastervolt launches

new MLI-E Lithium Ion battery

A compact power source ideal for mobile applications

Aimed to bridge the gap between Mastervolt’s most compact Li-Ion battery, the MLS series, and its high-capacity sister, the MLI Ultra, the new MLI-E is a fast-charging mid-size battery offering long life and deep-cycle discharge in a compact waterproof case.

Mastervolt, the Dutch-based pioneer of off-grid power systems, is pleased to announce the arrival of the first of the new MLI-E series of Lithium Ion batteries, the MLI-E 12/1200, a 12-Volt battery offering 1200 Watt-hours of energy (90 Amp-hours).

By using the very safe Lithium Iron Phosphate chemistry, the MLI-E saves up to 70 % in space and weight, recharges in less than an hour and can discharge 80 % of its capacity up to 5,000 times without damage, a lifespan that is ten times longer than an equivalent lead acid battery. This makes it ideal for mobile applications, and for powering small electric motors for propulsion.

Advanced management

A battery management system is incorporated into the casing. This BMS manages each cell independently protecting it from excessive discharge, overcharging and overheating. The electronics also ensure that each cell is charged in the optimum way, allowing for a very fast recharge time, ideal for mobile applications.

With no need to wire in an additional safety relay, the MLI-E series makes an easy to install, and straight swap for a conventional lead acid battery bank.

Precision monitoring

As another benefit to electric propulsion, where range is crucial, the MLI-E also offers integrated battery monitoring. Sensors relay details about the general status of the battery, including the state of charge and time remaining. The battery has CAN communication which allows the MLI-E to seamlessly integrate with Mastervolt products or other electrical components within an electrical system. The optional EasyView 5 display delivers all readouts via its customizable touchscreen.

Hands-on monitoring is also possible via Bluetooth, and by LED indicators set into the battery itself, which inform the user about the state of charge.

Long lasting power in a small package

Enclosed within a waterproof case that is both compact and practical, with large fold down carry handles, this is a high performance battery based on proven technology. Equivalent in size to the popular mobile lead acid service batteries, it can recharge within an hour, and offers a deep-cycle delivery ideally suited to applications requiring long life and automatic monitoring and management.

Key Features:

  • Compact, practical size similar to the LN5 – Group 49, H8 standard.
  • Very long lifespan with high efficiency.
  • Fully rechargeable within one hour.
  • Straightforward replacement for most existing lead-acid batteries.
  • Integrated monitoring for reliable battery status information.
  • Quick installation and commissioning. No maintenance needed.
  • Monitoring via a Bluetooth app.
  • CANbus communication for automated and intelligent energy system integration.
  • Safe and proven Lithium Ion chemistry (LiFePO4).        

Technical Specifications:

  • Model: MLI-E 12/1200.
  • Size: 353 x 175 x 190 mm (13.9 x 6.9 x 7.5 in).
  • Weight: 12.5 kg (27.6 lb).
  • Nominal voltage: 12 V.
  • No load voltage: 13.2 V.
  • Nominal capacity: 90 Ah.
  • Nominal energy capacity: 1200 Wh.
  • Max charge current: 90 A.
  • Continuous discharge current: 200 A.
  • Peak discharge current: 350 A for 30 secs.
  • Cycle life: up to 5,000 cycles.
  • Terminals: automotive or M8 hexagon.
  • Communication: CAN, Bluetooth, LED indicators.
  • Compatible with: MasterBus and CZone via EasyView 5.
  • Protection degree: IP65.
  • Safety protection:  over voltage, under voltage, over temperature.
  • Parallel connection: unlimited.
  • Included: 2 x automotive battery pole, 2 x M8 bolt, hex tool, manual on USB.

Mastervolt Alpha Pro III:

new charge regulator

For high-performance and standard alternators in rescue and emergency vehicles 

Mastervolt, the Dutch-based pioneer of off-grid power systems, announces the launch of a new Alpha Pro charge regulator. Alpha Pro III ensures fast and safe charging of service batteries in emergency vehicles – either while driving or idle. Protecting both the engine and the batteries, Alpha Pro III features higher power and improved ease of use. 

The Alpha Pro III measures the temperature and the voltage of your batteries to prevent overcharging, keeping them in perfect condition. It also monitors the engine load, thus reducing sound variations, wear and tear. The smart ‘keep alive’ feature solves a common problem causing unreliable tachometer readings. Via MasterBus, it communicates RPM, alternator status and state of charge of the battery to create intelligent power systems for professional mobile applications.

Due to increased power requirements, emergency vehicles – such as fire brigade, police, rescue or breakdown services – require a regulator that offers higher performance than the standard integrated versions. The standard regulator, designed for low cost and short charge cycles, charges at a slow pace and the battery is easily overheated. Replacing the standard regulator* of the alternator with the Alpha Pro III optimises this charging process, protects against overheating and overcharging and extends the lifetime of your batteries.

* not allowed on Euro 5/6 engines.

Optimised alternator and fast charge

For superfast charging of the service batteries at low RPM, Mastervolt suggests combining the Alpha Pro III with a high-performance alternator such as the reputable Alpha series. With 20 A of field current capability, the Alpha Pro is the only 3-step regulator on the market capable of handling alternators with outputs up to 400 A.

Features at a glance

  • Transforms any alternator into a 3-step charger with full temperature control.
  • Reduces run time, saves fuel, lowers engine noise and emissions.
  • Protects from overcharging for greater battery life.
  • Balances engine load to smooth out RPM variations.
  • Compatible with all standard alternators, including performance 200 A - 400 A models.
  • Integrated ‘keep alive’ feature for reliable tachometer readings.
  • Suitable for every type of battery chemistry, including Li-Ion.
  • Works with both 12 V and 24 V systems.
  • MasterBus compatible: simplifies wiring, saves space and weight, and creates optimal cooperation between Mastervolt products.

Technical Specifications:

  • Model: Alpha Pro III.
  • Dimensions: 90 x 109 x 30 mm.
  • Weight: 0.4 kg.
  • Output voltage: 12 V / 24 V selectable.
  • Alternator types: negative excitation up to 20 A field current.
  • Battery types: all types, including Lithium Ion.
  • Bulk/Absorption/Float voltage: AGM, Gel and Lithium Ion pre-sets/adjustable.
  • Absorption time: 4 hours, adjustable from 0 minutes to 10 hours.
  • Voltage drop compensation: up to 3 V.
  • Delivered with: battery temperature sensor with 6 m of cable.

Alpha Pro III is ideal for improving the performance of a standard alternator in emergency vehicles as well as boats and other vehicles with service batteries. Combining the three-step regulator with a high performance alternator can even replace a standard generator.

New Charge Mate Pro 90

controlled charging from one source

The new Charge Mate Pro 90 is an electronic relay that allows a second battery to receive up to 90 A of charge current from a single alternator. Suitable for all battery types, it is ideal for recharging Lithium Ion cells and has built-in safety features. An effective solution for high power demand on board in combination with a need for prioritised or current limited charging.

Mastervolt, the Dutch-based manufacturer of off-grid power solutions, has added a new and more powerful model to its highly successful Charge Mate Pro series of electronic charge relays. The new 90 A model supplements the 40 A version already available, and will quickly and intelligently charge two batteries from just one source when higher charge currents are demanded for, e.g. when charging  Li-ion batteries. When used in parallel they are even suitable for large automotive alternators up to 225 A.

Safety is a priority

When there are two batteries on board, typically an engine start battery and a service battery, the second battery usually requires its own charging solution.  A mechanical relay will charge the flattest battery first, and then switch to the other, but this isn’t always ideal, as it could leave the engine starter battery discharged.

The new Charge Mate Pro 90 works differently, by always prioritising the primary battery whilst still charging the secondary. A very effective solution for charging two batteries from one source, while significantly reducing the risk of a flat battery.

An example would be a bow thruster battery and a service battery connected to the same alternator. The Charge Mate Pro 90 would prioritise the service battery for the bulk of the charge, whilst still feeding current through to the bow thruster battery. Any return current is automatically blocked, even if the secondary battery is of a higher voltage, which helps to keep the bow thruster battery sufficiently charged. The current limiting prevents power dips of the on board electrical network.

In the event of a main battery failure, an emergency start facility is available by means of an optional bypass or ‘battery bridge’ switch.

Built to last

Mastervolt is the official supplier to gruelling yachting events such as the Volvo Ocean Race because the products are built to last, and the Charge Mate Pro 90 is no exception. Designed for the harsh marine environment, the relay is suitable for all types of battery chemistry and alternators, and the electronics are rated to the demanding IP65 standard.

The relay is housed in a corrosion-resistant housing flanked by two heat sinks, and its operation can be monitored via built-in LED indicators. The unit includes automatic battery detection, so it can work seamlessly with either 12 V or 24 V systems.

The Charge Mate Pro 90 adds to the existing model line-up, and offers a unit that is easy to install and meets the demand for prioritisation or current limitation.


  • Makes effective dual charging possible.
  • High system reliability by prioritised charging of the main battery.
  • Fast and easy installation.
  • Suitable for all battery types, including Lithium Ion.
  • Charge current to secondary battery limited to 90 A.
  • Return current blocked under all circumstances.
  • Prevents power dips of the on-board electrical network.
  • Works with all types of chargers and alternators.
  • IP65 electronics in a corrosion resistant case.
  • Monitoring via LED status indicator.          

Technical specifications:

  • Model: Charge Mate Pro 90.
  • Type: electronic relay with low voltage drop of 0.2 V max.
  • Size: 157 x 140 x 80 mm (6.2 x 5.5 x 3.1 in).
  • Weight: 0.88 kg (1.9 lb).
  • Input voltage: 9 – 32 V.
  • Battery voltage: automatic 12/24 V detection.
  • Battery types: all chemistries.
  • Output current: limited to 90 A (derating above 25 °C).
  • Switch on voltage: 13.5/27 V after 5 sec (12/24 V).
  • Switch off voltage: 12.75/25.5 V after 2.5 sec (12/24 V).
  • Number of batteries: 2.
  • Remote switch functions: On, Off, Auto, Start assist.
  • Parallel operation: yes.
  • Protection degree: IP65.
  • Ambient temperature: -40 °C to 60 °C.
  • Approval: CE.
  • Connections:
    - 3 x fast-on connectors (switch, ground and status).
    - Switch: offers an optional single pole switch for remote operation.
    - Status: for an optional LED indicator.