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Mastervolt Charge Mate Pro Lithium 40 [83304004]

Mastervolt Charge Mate Pro Lithium 40 [83304004]

Regular price $239.95 USD
Regular price $315.00 USD Sale price $239.95 USD
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Charge Mate Pro Lithium 40

Current limited electronic charge relay with high efficiency and reverse current protection

A secondary battery on board requires a dedicated charging solution. The Charge Mate Pro charging relay makes it possible to distribute the charger or alternator current effectively between two battery banks such as a starter and a service battery. The Charge Mate Pro connects both batteries during charging and keeps them isolated when discharging. This significantly reduces the risk of a flat starter battery for example.

The Charge Mate Pro offers an additional advantage over mechanical charge relays, by limiting the charge current to the second battery. The primary battery, like a starter battery, is therefore charged with priority. The return current is automatically blocked even when the secondary battery has a higher voltage. An emergency start function is possible by connecting an optional bypass switch to the Charge Master Pro.

A marine application example is the connection of a bow thruster battery to a service battery. The Charge Mate Pro ensures that the service battery is always charged with priority. The blocking of the return current from the bow thruster battery guarantees that the bow battery remains charged while the current limiting also prevents power dips of the onboard electrical network.

The Charge Mate Pro series consists of a 40 Amp and a 90 Amp version, both suitable for charger or alternator applications. 

Charge Mate Pro: for controlled charging from a single source.


Leisure and professional marine and mobile applications. An effective solution for high power demand on board and/or the need for prioritized or current limited charging.


  • Electronic charge coupling with very low voltage drop.
  • Makes effective dual charging possible.
  • Suitable for charging from Lithium starter batteries to AGM/GEL/Lithium service batteries.
  • Charge current secondary battery limited to 40 A.
  • High system reliability by prioritizing charging of the main battery.
  • Unidirectional which blocks return current under all circumstances.
  • Prevents power dips in the onboard electrical network.
  • Suitable for all kinds of chargers and alternators.
  • Monitoring with LED status indication.
  • IP65 electronics in a corrosion-resistant casing with aluminum heat sinks.
  • Fast and easy installation

General Specifications:

  • Monitoring: LED (warnings and status indication)
  • Output current: Limited to 40 A
  • Number of battery outlets: 2
  • Input voltage range: 9-32 V
  • Parallel configuration: Yes
  • Battery voltage: automatic 12/24 V detection
  • Remote switch functions: On, off, auto, start assist
  • Dimensions, hxwxd: 157 x 140 x 80 mm/6.2 x 5.5 x 3.1 inch
  • Weight: 0,88 kg/1.9 lb
  • Compliance: CE

Technical Specifications:

  • Connection possibilities: 3 x fast-on connectors (switch, ground, and status) • switch: for an optional single pole ON-OFF-ON switch for remote operation • status: for an optional LED indicator
  • Power consumption: Switch open: < 1 mA at 12/24 V DC
  • Battery types: Suitable for charging from Lithium starter batteries to all types of batteries (for AGM/GEL starter battery applications, please use 83304002)
  • Switch on voltage: 13.7 V (12 V) / 27.4 V (24 V)
  • Switch on delay: 5 sec
  • Switch off voltage: 13.3 V (12 V) / 26.6 V (24 V)
  • Switch off delay: 2,5 sec
  • Relay: Electronically (MOSFETs with a low voltage drop of max 0.2 V)
  • Temperature range (ambient temp.): -40 °C to 60
  • Protection degree: IP65

Owner's Manual (pdf)
Brochure (pdf)