


A fish finder is useful only while its display, GPS and sonar module stay powered. A weak or shared lead-acid battery can leave electronics with less usable runtime than its label suggests, especially after a trolling motor or engine starter pulls from the same bank. Epoch LiFePO4 fish finder batteries provide more routinely usable energy for their size, hold voltage more steadily and cut the weight carried by a small boat. Bluetooth-equipped choices let you check the remaining charge on a nearby phone before launching or extending a fishing day.
The Epoch Fish Finder Batteries collection contains three 12V options: a compact 50Ah Essential, a 100Ah Eco and a heated 105Ah Essential. They suit different combinations of screen size, live imaging, trip duration and monitoring needs. A dedicated electronics battery can also keep fish finder loads apart from engine starting and high-current trolling circuits. Select capacity from the equipment actually connected, then make the wiring and charging match the battery.
A kayak with a single small display has a different load from a bass boat carrying two bright screens, a live imaging module and a network hub. The battery that is generous for the first setup could be undersized for the second. Likewise, adding capacity will not repair a loose connector, an undersized cable or interference from an adjacent trolling-motor line. Plan the electronics circuit as carefully as the battery itself.
All three choices use LiFePO4 chemistry and a built-in BMS. The 50Ah option favors a compact dedicated setup, while the two Group 24 choices provide more stored energy for additional displays or longer trips. Bluetooth and cold-weather features differ, so select the actual model rather than assuming every lithium fish finder battery has the same electronics.
| Epoch battery | Energy and case | Features and potential fit |
|---|---|---|
| 12V 50Ah Essential | 0.64kWh; Group 22NF; 14 pounds; IP54. | Compact dedicated electronics power with Bluetooth; no internal heating. |
| 12V 100Ah Eco | 1.28kWh; Group 24; 21 pounds; IP54. | More energy for extended electronics use; no Bluetooth or heating. |
| 12V 105Ah Essential | 1.34kWh; Group 24; 22.1 pounds; IP54. | Larger monitored electronics bank with Bluetooth and internal heating. |
The Eco and 105Ah Essential share the Group 24 footprint class, but only the Essential has phone monitoring and a heater. The smaller 50Ah Essential also has Bluetooth, though it is unheated. If a boat's combined electronics, pumps and lighting demand more than this collection can sensibly support, compare a larger Epoch marine house battery as part of a broader bank design. That is a different job from replacing the starter battery.
List everything that turns on with the fish finder: the screen, sonar black box, GPS or chartplotter, Ethernet or network hub, transducer accessories and any USB power sharing the circuit. Read the manufacturer's maximum or typical current draw at the specified voltage, then estimate hours at the brightness and settings you use. For a simple 12V system, multiply combined amps by hours to estimate amp-hours before adding a reserve.
For example, electronics drawing a combined 3A for a ten-hour day use about 30Ah on paper. Adding a 25% planning margin brings the target to roughly 38Ah, before accounting for unusual loads, temperature or aging. A 50Ah battery might suit that assumed day; the result changes if a live imaging module or second high-brightness display doubles the draw. Always verify the equipment's actual draw and leave charge for the return trip rather than treating the arithmetic as guaranteed runtime.
Watt-hours help when devices list watts instead of amps: divide watts by the system voltage for an approximate current, or multiply power by operating hours for energy use. A fish finder bank should also meet the electronics manufacturer's voltage range at the end of the cable run. Choosing 100Ah when the system needs only a fraction of that adds weight and takes space, but choosing 50Ah solely because it fits the tray can leave a full-day live sonar setup short.
On the 50Ah or 105Ah Essential, the compatible Epoch app can show state of charge, voltage, current and temperature locally. Check after charging at home or the dock, then again when an afternoon of sonar and mapping has passed. The reading helps you decide whether to keep both screens bright or save energy for navigation and the ride back. LiFePO4 voltage stays relatively flat through much of its usable range, so a voltage-only dashboard gauge is a poor substitute for a monitored charge estimate.
The 100Ah Eco does not include Bluetooth; use an appropriate external monitor if you need a charge reading for that bank. Bluetooth does not automatically send an alert to a phone away from the boat. When several devices and charging sources share one circuit, a bank-level monitor can complement an individual battery app by showing the whole system's net use.
Run adequately sized marine wiring to the electronics with a correctly rated fuse near the battery positive terminal. Protect connections from corrosion, secure the battery against motion and route sonar power away from trolling motor cables where practical. A dedicated electronics supply can reduce shared voltage dips and make noise troubleshooting easier, but a battery alone cannot guarantee a clear sonar image if grounding, transducer placement or wiring is faulty.
Epoch's BMS helps protect against over-discharge, excessive current and unsafe temperatures. Its protective cutoff can also turn off the connected fish finder. Keep a reserve rather than planning to run to cutoff, and maintain separate, appropriately rated engine-start power. None of the three fish finder collection models is presented as a cranking replacement.
IP54 cases belong in a suitably protected, dry location even aboard a boat. Do not submerge the battery or leave terminals exposed to standing water. The 105Ah Essential can use incoming charging power to warm cold cells before normal charging within its published limits; the unheated 50Ah Essential and 100Ah Eco may block charging when too cold. Check the chosen model's charge profile and temperature rules, including for an onboard charger or solar controller.
Epoch fish finder batteries offer more practical electronics energy than a comparable lead-acid battery in a smaller, lighter setup, with steadier voltage and fewer maintenance chores. The 50Ah and 105Ah Essential models add Bluetooth visibility, while the Eco emphasizes uncomplicated storage. Size the bank to the combined displays and modules, protect the electronics wiring and reserve enough charge for the whole outing.
Explore Epoch Fish Finder Batteries, or contact Epoch support with your fish finder models, expected hours, charger and available battery space to narrow down a suitable choice.
Side-by-side specs
Every battery in this collection uses LiFePO4 chemistry with a built-in battery management system (BMS). Compare stored energy, continuous output, weight, footprint, and price side by side.
3 models · Select a column heading to sort
| Model | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
![]() | 50Ah | 0.64 kWh | 50A | 14 lbs | 9 × 5.6 × 8.3 | 22NF | 4,000+ | 11 yr | IP54 | Bluetooth: yes | Heated: no | Victron communications: no |
![]() | 100Ah | 1.28 kWh | 100A | 21 lbs | 10.3 × 6.8 × 9 | 24 | 4,500+ | 6 yr | IP54 | Bluetooth: no | Heated: no | Victron communications: no |
![]() | 105Ah | 1.34 kWh | 105A | 22.1 lbs | 10.3 × 6.8 × 9 | 24 | 4,000+ | 11 yr | IP54 | Bluetooth: yes | Heated: yes | Victron communications: no |
Our core line of drop-in LiFePO4 batteries for marine, RV, golf cart and off-grid power.
Our most affordable LiFePO4 line: proven lithium power without the extras.