Epoch 36V 50Ah Essentials Lithium Trolling Motor Battery 3650A-H, Group 31, 1.92kWh LiFePO4, Heated, Bluetooth, IP65

About the Epoch 36V 50Ah Essentials Trolling Motor Battery

A 36V trolling motor usually means three 12V lead-acid batteries, two series jumpers and a lot of weight in the boat. This 36V lithium trolling motor battery does the same job in one 35 lb case. The motor leads land on a single pair of terminals, and one 36V LiFePO4 charger tops it up. It uses a BCI Group 31 footprint, a common size for marine battery trays.

For planning, Epoch counts on about 80% of nominal energy, roughly 1,536Wh per battery. That's about 4 hours at an average 10A draw, or about 3.1 hours at a steady 500W. Epoch treats those as conservative planning numbers, not ratings. Hold it down with the Epoch tray built for the 3650A-H, or any strap or bracket rated for 35 lb.

36V 50Ah vs 36V 100Ah: Choosing a Lithium Trolling Motor Battery

Epoch builds two 36V trolling motor batteries, and the choice comes down to runtime, weight and space. The 50Ah weighs 35 lb and fits a Group 31 footprint. It suits half-day trips, smaller boats and anyone who carries the battery to and from the boat. The Epoch 36V 100Ah doubles the energy to 3.84kWh in a single 75 lb case. It adds IP67 immersion protection, a 200A peak that holds for up to 60 seconds, and a 10-segment battery meter in the box.

There's a middle path too. Two matched 50Ah batteries, bought together and wired in parallel, make a 100Ah bank split into two 35 lb cases. That can be easier to lift and to fit into separate compartments. Up to four can share a bank for 200Ah. If you're weighing one battery against two for your motor and typical day on the water, our team is happy to help with sizing.

Heated Charging and Bluetooth Monitoring

The built-in heater lets the battery take a charge in a cold garage or at a frosty dock. When the cells reach 32°F (0°C), the BMS pauses charging. It sends charger current (0.5A or more) to internal heating pads, then resumes charging on its own at 41°F (5°C). The heater runs only on incoming charge current, so the energy you stored stays available for the motor.

The Epoch Li-Ion app (iOS and Android) shows state of charge, voltage, current, temperature and alarms. The shunt built into the BMS reads current to within 0.2A on discharge, so there's no separate battery monitor to wire in. A PIN printed on the lid secures the Bluetooth connection, and you can change it in the app.

Wiring, Fusing and Charging a 36V Lithium Trolling Motor Battery

Installation is straightforward if you're comfortable with DC wiring. Mount the battery upright. Land the motor leads on the M8 female terminals with clean, properly crimped lugs. Torque them to 71 to 106 in-lb (8 to 12 N·m). Size the cable for the motor's current, the run length and voltage drop. Our custom battery cable builder makes leads to length from 6 AWG to 4/0 AWG.

Epoch calls for a fuse or DC-rated breaker as close as practical to the positive terminal, sized to protect the smallest wire in the circuit. Loads, cable and protection get sized to the 100A continuous rating, not the 10-second peak. When you parallel two to four batteries, charge each one fully first and keep cable lengths and gauges equal. Protect the bank's main positive with a Class-T fuse.

Charge with any charger, converter or charge controller set to a 36V LiFePO4 profile. To charge from an engine alternator, Epoch highly recommends a DC-to-DC charger to protect both the alternator and the battery.