Homepage / Li-Ion Batteries / Subsea Batteries /

Subsea Batteries


Simplify your system design with SubCtech batteries: ⇒ lower your CAPEX
Use SubCtech batteries: ⇒ lower your OPEX.

High power underwater Lithium-Ion rechargeable batteries (Li-Ion PowerPacks™) have proven themselves as suitable offshore power supply systems on many occasions. This type of Li-Ion cells is used in aircrafts, space vehicles as well as naval applications. The sophisticated battery management system (SmartBMS) guarantees highest performance without any risks, allowing the use of high-power Li-Ion systems in offshore and other rough environments.


  • Subsea electric systems, „All Electric“
  • Subsea UPS
  • Monitoring, sensor systems


  • High safety: multiple independent system monitors. Handy blocks of low energy, low weights and low voltages
  • High reliability: optional redundant design with at least 50% capacity in all circumstances
  • Minimum costs: long operating life, short charging cycles
  • Simple handling: only 2 buttons to control the charging unit. Charging without opening the battery, simply underwater
  • Easy maintenance: little time and costs
  • Highest rated power: Very high capacities with optimized weight and size lead to significantly expanded operating times


  • High-power up to 30+kW
  • High-energy up to 100+kWh
  • Voltage range 14,4V up to 400+V
  • Currents up to ~100A
  • Design life up to 30 years, service life typ. 15 years
  • Data interface RS-232/485, galvanic de-coupled, ASCII NMEA-0183 or MODBUS RTU, CAN or Profinet on request
  • Simple installation and operation
  • Design, capacity and mechanical customization for your project


  • ISO 13628-6 or API17F,N for industrial applications
  • EMC tests according to API17F, MIL-STD, DIN-EN, GL
  • Production according e.g. IPC-A-600/610 class 2 or 3.

Product overview:

SEM with Li-ion buffer battery and subsea charging Manifold with Li-Ion battery and ISO ROV switch
400V 1kW Subsea UPS – API17F qualified
200V 10kW Subsea UPS – API17F qualified / SIL2 pending
Large Subsea UPS 25kW
19″ diagnostic Unit