Mastervolt Launches MLI Ultra 2 Modular Marine Pack with Integrated CAN-Bus BMS
Mastervolt's second-generation MLI Ultra brings 5.5 kWh stackable modules, 200 A continuous discharge per module, and native VE.Can integration with Cerbo GX — targeting the 20–80 kWh marine retrofit segment.
Mastervolt has unveiled the MLI Ultra 2, the successor to its long-running MLI Ultra modular lithium pack series. Each module holds 5.5 kWh of usable LiFePO₄ at 25.6 V nominal (eight cells in series), can be paralleled into a 25.6 V bank up to 88 kWh total, or stacked in series-parallel for 51.2 V (24 V × 2) and 102.4 V (24 V × 4) bus voltages. The headline change versus the original MLI Ultra is the integrated CAN-bus BMS that speaks both the Mastervolt MasterBus protocol and Victron's VE.Can / BMS-Can dialect natively — meaning the same module can drop into a Mastervolt PowerCombi installation or a Victron Cerbo-orchestrated system without a protocol translator.
Electrically, each module supports 200 A continuous discharge and 400 A peak for 30 seconds, rated at 25.6 V nominal — sufficient for direct connection to a 5–8 kW motor controller without paralleling. For larger systems, four modules paralleled at 25.6 V deliver 800 A continuous (≈20 kW), and the BMS-level current sharing has been re-engineered to keep individual module currents within ±2% even as cells age unevenly across the lifetime of the pack.
Thermal management is passive — there is no internal cooling fan or coolant loop, which keeps the IP65-rated enclosure free of seals and pumps that historically failed in marine environments. Mastervolt cites a 6,000-cycle warranty at 80% retained capacity under 25 °C ambient, with an explicit derating curve published for ambient temperatures up to 50 °C in engine-room installations.
For sailors retrofitting an electric drive, the practical advantage of the new generation is wiring simplicity. A single VE.Can cable from the module stack to a Cerbo GX or Cerbo GX MK2 carries SoC, CCL, DCL, cell-level voltages, and individual cell temperatures — eliminating the multi-wire two-signal BMS interface that previous-generation packs required. Pricing in Europe is approximately €4,200 per 5.5 kWh module, putting a 30 kWh stack at around €23,000 including installation hardware. Mastervolt has confirmed European dealer availability from June 2026.