MASTERVOLT MLI Ultra 1250 Battery Wins 2021 DAME Design Award

AMSTERDAM (November 16, 2021) - Mastervolt, a division of Brunswick Corporation’s (NYSE: BC)  Advanced Systems Group (ASG), has been awarded a 2021 DAME Design Award in the Machinery, Propulsion, Mechanical and Electrical Systems and Fittings category for its MLI Ultra 1250 battery. The announcement was made during the first day of the METSTRADE show in Amsterdam.

Making its world debut this year, the MLI Ultra 1250 is the most compact battery in Mastervolt’s range and is ideal for both marine and mobile applications. This is due to the high energy density within the battery cells which together offers up to 70% space and weight savings compared to traditional lead-acid batteries. Weighing just 15 kg and measuring 330 x 173 x 210 mm, the MLI Ultra 1250 offers a considerable benefit for vessels and vehicles where space is at a premium. It has been designed as a drop-in replacement for size Group 31 and Group 49 (85-90 Ah) batteries.

The DAME Awards jury stated, “Mastervolt’s MLI Ultra 1250 lays a significant marker in terms of where battery technology is headed.”

“We’re absolutely delighted to win this prestigious Marine industry award, recognising our commitment to market leading innovation,” said Ton de Winter, President of ASG EMEA. “We are excited that the Mastervolt MLI Ultra 1250 has been recognised as an alternative green energy source and for its size and affordability making Lithium Ion battery technology more accessible to a wide group of boaters. This also supports our commitment to Brunswick’s ACES strategy, providing unrivalled electrification solutions to our global customers.”

Available in both 12 V and 24 V models, the MLI Ultra 1250 has a realistic lifespan of over 2000 cycles at an impressive depth of discharge (DOD) of 80 %. This deep cycling means five times more energy storage than lead acid batteries thanks to exceptionally high efficiency and the minimal build-up of the infamous ‘memory effect’. As with the whole MLI Ultra range, the MLI Ultra 1250 can be recharged within 60 minutes.

Features of the Mastervolt MLI Ultra 1250

  • Ultimate performance, heavy duty Lithium Ion batteries
  • BMS and LiFePO4 chemistry according to highest safety standards
  • Drop-in replacement for size Group 31 and Group 49 (85-90 Ah) batteries
  • More than three times the lifespan of traditional batteries
  • Saves up to 70 % in space and weight
  • High charge / discharge rate up to 2 C
  • Fast charging within 60 minutes
  • Series connection up to 48 V possible
  • Integrated Battery Thermal Control
  • Integrated battery switch and battery monitoring (Voltage, Current, State of Charge, Time Remaining)
  • MasterBus communication with any Mastervolt Battery Charger or Smart Remote
  • CZone and NMEA2000 compatible
  • Fully waterproof (IP65)
  • Designed according to UN38.3
  • CE, E-Mark, FCC and compliant to RVIA standards (pending)


Mastervolt is part of Advanced Systems Group (ASG) by Brunswick. ASG is the world’s leading supplier of products and integrated systems to the marine, RV, and Specialty Vehicle industries. The broad portfolio of market leading brands in power management, digital control and monitoring, electrical components, networking devices and water systems include Ancor, Attwood, B&G, BEP, Blue Sea Systems, C-MAP, CZone, Garelick, Lenco, Lowrance, Marinco, MotorGuide, Mastervolt, ProMariner, RELiON, Simrad and Whale. ASG is driven, every day, to be the world’s most trusted partner to the marine and mobile industries.