Marine RV 8S-16S 24V 48V 200A Active Balance BMS JNFN ANT 16MDA Deep Cycle Lithium Bank

The JNFN ANT 16MDA is a low-voltage active-balancing battery management system for 8 to 16 series packs in the 24 V and 48 V class, dimensioned for the long, slow duty of a house bank rather than the short bursts of a traction pack. On a sailing yacht, a camper van or an off-grid cabin, the battery spends most of its life at part state of charge, charges from an irregular source, and is asked to deliver a predictable 150 to 200 A when an inverter or a bow thruster calls for it. Those three conditions - partial cycling, uneven charging and occasional heavy loads - are exactly where passive balancing quietly loses capacity.

This model therefore centres on a 2.5 A transformer-based balancing stage. A resistive bleeder equalises a 16S pack at a few tens of milliamps and effectively never catches up on a bank that is cycled shallowly every day; the 16MDA moves energy instead, which shortens the time a pack spends with a voltage spread and keeps the absorption phase honest. Around that core, the board adds the functions that a marine or vehicle electrical system actually needs: a charge lockout that refuses current below freezing, a heating-pad output that brings the pack back into range, a published Modbus register map for a PLC or a monitoring gateway, and dry contacts that can trip a panel alarm.

• 2.5 A Transformer-Based Active Balancing: The balancing stage transfers charge between neighbouring cells through a small transformer rather than dissipating it in a resistor. On a 16S bank with a 120 mV spread after a partial cycle, the pack returns to within 20 mV in a single absorption window, which protects the weakest cell from repeated early cut-off and keeps delivered capacity close to nameplate over the bank's service life.
• Low-Temperature Charge Lockout with Heating Control: Charging below 0 °C is the fastest way to plate lithium metal onto an anode, and a bank sitting in an unheated locker reaches that temperature every winter. The board blocks charge current at a programmable threshold, energises a dedicated heating output to warm the cells, and only re-enables charging once the pack is back inside the safe window - all without operator intervention.
• Published Modbus RTU Register Map: A complete register table - cell voltages, temperatures, pack current, SOC, SOH, alarm words and configuration block - is issued with the product, so a system integrator can map the pack into a PLC, a vessel monitoring system or a custom gateway in an afternoon rather than probing frames with a scope.
• Parallel Bank Coordination: Up to eight packs can be tied together over RS485 with master-slave arbitration, each contributing current according to its own SOC and internal resistance. Anti-circulation logic prevents a freshly charged pack from dumping current into a depleted neighbour through the shared bus.
• Marine-Grade Coating and IP65 Sealing: Conformal coating over the control section, tinned copper terminals and a gasketed housing address salt-laden air and condensation cycling. Terminal hardware is stainless, because a rusted stud on a house bank is a maintenance problem long before it becomes an electrical one.
• Dry Contact and Buzzer Outputs: Two configurable relay outputs can drive a panel annunciator, a shunt trip or an external contactor, so an alarm is visible at the helm or in the cabin instead of only inside an app.
• Coulomb-Counted SOC with Cycle History: SOC is tracked by integrating current rather than reading open-circuit voltage, holding within approximately 3 percent through partial cycles, and a rolling history of 2000 cycles supports warranty discussions with real data.

The primary fit is a 48 V marine house bank on sailing yachts, trawlers and inland cruisers, where the pack sits below the waterline, charges from alternator, shore power and solar in the same week, and feeds an inverter for galley loads. The same board serves camper vans and expedition vehicles running 12 V and 24 V auxiliary systems, where a heated locker and a reliable low-temperature charge block matter more than peak current.

Off-grid cabins, telecom backup cabinets and small workshop storage systems use the 16MDA where a bank must run unattended for months. Installers appreciate the published register map because it lets them fold the battery into an existing monitoring platform instead of adding a dedicated display at every site.

Delivery includes the management board, a labelled balance harness, four NTC probes, a terminal cover, a DB9 service lead and a printed wiring diagram; the Modbus register table is supplied as a spreadsheet on request. Every board is burn-in tested with a simulated pack profile before shipment, and the serial number is matched to the test record.