12V 300Ah Cranking & Deep Cycle Lithium Battery (Dual Purpose) - Pro Series

Yes. The Epoch 12V 300Ah Group 8D LiFePO4 battery is designed for both engine starting and deep-cycle power applications. It delivers up to 1,000A of peak discharge for 5 seconds and 800A for 10 seconds, providing the power needed to start compatible marine engines. Epoch specifically notes compatibility with Mercury 250 hp motors when the electrical system is properly matched. In addition to starting power, the battery provides 300Ah of capacity for electronics, trolling motors, lighting, and other onboard equipment. Always verify compatibility with your engine and charging system before installation.

In many compatible marine systems, no. A 12V 300Ah dual-purpose lithium battery combines engine-starting power and deep-cycle energy storage in a single unit. It can power fish finders, bilge pumps, lighting, marine audio, refrigeration, and other 12V accessories while still providing the cranking power needed to start compatible marine engines. Always verify compatibility with your electrical system before installation.

Yes, this battery is designed around a Group 8D marine battery footprint. Epoch lists the dimensions as 19.70 in L × 10.5 in W × 9.75 in H. If you currently run a Group 8D lead-acid or AGM battery, this lithium upgrade is intended to fit the same class of tray, but you should still verify tray dimensions, hold-downs, lid clearance, terminal access, and cable reach before ordering.

The Epoch 12V 300Ah Group 8D lithium battery weighs 81 lbs. Many traditional Group 8D lead-acid or AGM batteries weigh roughly 130 to 160 lbs, so switching to this battery can cut battery weight dramatically while increasing usable capacity. Less stern weight can help improve boat balance, hole shot, draft, and fuel efficiency depending on the vessel.

Yes. Epoch lists this Pro Series model as supporting up to 16 batteries in parallel for expanded 12V capacity and up to 4 batteries in series for 24V, 36V, or 48V systems. Use matched batteries of the same model, age, capacity, and state of charge, and follow Epoch’s series/parallel, communication, fusing, and charger guidance.

This battery is IP67 rated, meaning it is dust-tight and protected against temporary immersion under specified conditions. It is built for demanding marine and mobile environments, including wet compartments and splash exposure. It should still be mounted securely, protected from physical damage, and installed with proper cable routing, fuse protection, and terminal protection.

Yes. Bluetooth monitoring is built in, so you can use the compatible Epoch app from an iOS or Android device to view battery information such as state of charge, voltage, current, temperature, and battery status. The Pro Series also supports over-the-air firmware updates through the app.

Yes. This battery includes CAN / RS485 communication and Victron communications support, allowing compatible systems to monitor and communicate with the battery string. The Pro Series communications box is available for expanded inverter and NMEA 2000 compatibility where required.

Yes. Built-in heating allows charging in sub-zero conditions when the battery is connected to compatible charging equipment and installed according to Epoch guidance. The product page lists a charge temperature range down to -20°C / -4°F with heating.

Use a lithium-compatible charger, inverter charger, converter, solar charge controller, or DC-to-DC charger programmed for LiFePO4 batteries. Epoch’s recommended charging settings include 14.2V–14.6V bulk/absorption, 13.4V–13.8V float, equalization disabled, temperature compensation disabled, and a charge rate around 50% of the battery or battery-bank capacity.

A 12V 300Ah lithium battery provides 3,840Wh of energy storage, up to 8,000 cycles at 80% depth of discharge, and more usable capacity than many lead-acid batteries. It also charges faster, weighs less, and delivers more consistent power throughout the discharge cycle for reliable performance.

A 12V 300Ah lithium battery is well suited for marine electronics, trolling motors, RV power systems, off-grid solar installations, overlanding setups, and backup power applications. Its large energy capacity supports extended runtimes for appliances, electronics, and essential equipment. The battery’s lightweight LiFePO4 design, long cycle life, and reliable performance make it a practical choice for demanding energy needs.