Mastervolt MLI Ultra 12/1250 Lithium-Ion Battery
Mastervolt MLI Ultra 12/1250 delivers 100Ah LiFePO4 capacity with integrated BMS, safety switch, heat pad, and networked marine battery monitoring.
The Mastervolt MLI Ultra 12/1250 is a compact 100Ah lithium-iron-phosphate battery rated at 1.25kWh for high-use marine DC systems. An integrated battery management system monitors cells and provides state-of-charge information, while MasterBus, CZone, and NMEA 2000 connections support coordinated charging and monitoring. Its internal safety switch and temperature-controlled heat pad make it distinct from the larger MLI models; installers should still confirm charger compatibility, communications, protective devices, and the correct 12V system design before replacing lead-acid batteries.
- 100Ah / 1,250Wh LiFePO4 battery with integrated BMS
- Integrated safety switch and thermal heat pad for cold-weather charging management
- CZone, NMEA 2000, and MasterBus communication
- 200A maximum continuous discharge current; 500A peak for 10 seconds
- IP65 protection; UN38.3 tested
Manufacturer | Mastervolt |
Category | Batteries |
Item Number | 66011250 |
Series | MLI Lithium Ion Series |
Protections/ Certifications | UN38.3 tested; CE; E-Mark; FCC; IP65; UL1642 applies to cells only; RVIA compliant |
Connection/Terminal | M8 threaded |
Dimensions | 330 × 173 × 210 mm (13.0 × 6.8 × 8.3 in) |
Weight | 15 kg (33.1 lb) |
Material | Lithium iron phosphate (LiFePO4) |
Voltage Type | DC |
Nominal Voltage | 12 V |
Capacity | 100 Ah / 1,250 Wh |
AMPS/Current Rating | Max. charge: 100 A; continuous discharge: 200 A |
Spec Sheet | View Manufacturer Spec Sheet |
- Chemistry: lithium iron phosphate (LiFePO4)
- Nominal voltage: 12V
- Capacity: 100Ah / 1,250Wh
- Maximum charging current: 100A (recommended 50A or less)
- Maximum continuous discharge current: 200A
- Peak discharge current: 500A for 10 seconds
- Cell monitoring: integrated BMS and state-of-charge reporting
- Communication: MasterBus, CZone, NMEA 2000
- Protection: IP65; integrated safety switch
- Terminals: M8
- Dimensions (L × W × H): 330 × 173 × 210 mm (13.0 × 6.8 × 8.3 in)
- Weight: 15 kg (33.1 lb)
- Cycle life: 3,500 cycles at 80% DOD under stated manufacturer conditions
Call for pricing. No exact SKU match in the Wards retail price export dated August 27, 2026.
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