Deep Cycle Marine Battery

Choose the Best Fish Finder Battery

miady 12v16ah w150pxFish finders are often key elements for having a great fishing trip or coming home empty-handed. Most common fish finders don't require large currents to operate, but the power supply must be constant and reliable.

On the larger vessels, when the main engines are off, fish finders are powered via the boat's onboard battery (or batteries). On smaller boats, kayaks, pontoons, or even inflatables, fish finders are often powered via dedicated batteries that must supply enough power for the fish finder to operate properly during fishing.

Updated: August 2, 2021.

On This Page:


Intro to Fish Finder Batteries

Powering fish finders, sonars, GPS and other electronics on larger fishing boats is not a problem - just plug the devices in and few Amps of current will hardly discharge the main deep cycle (or dual-purpose) marine battery, which is often connected to solar panels, wind turbine or at least, to the main engine's alternator.

However, when it comes to small fishing boats, pontoons, kayaks, and even canoes, the situation is not that simple.

Some of the best and most popular fish finder batteries are 12V AGM/Gel-cell Sealed Lead-Acid (SLA) and lithium deep cycle batteries, with both types having their pros and cons.

The following comparison chart lists 12V AGM/Gel-Cell general-purpose (deep-cycle) lead-acid batteries with their capacity, size and weight:

Model Capacity Size (H x L x W) Weight
Chrome Battery 12V 7AH Battery 7 Ah 3.72 x 5.94 x 2.56 inches 4.1 lbs
ExpertPower 12V 7Ah Battery 7 Ah 3.70 x 5.94 x 2.56 inches 4.52 lbs
UPG 12V 7Ah SLA Battery 7 Ah 3.86 x 5.94 x 2.56 inches 4.80 lbs
UPG 12V 8Ah Battery With Charger 8 Ah 3.94 x 5.94 x 2.56 inches 4.96 lbs
UPG 12V 9AH Battery With Charger 9 Ah 4.06 x 5.94 x 2.56 inches 5.17 lbs
ExpertPower 12V 12 Ah Battery 12 Ah 3.9 x 5.94 x 3.86 inches 7.61 lbs
Mighty Max 12V 12Ah Battery 12 Ah 4.00 x 5.94 x 3.88 inches 8.38 lbs
Chrome Battery 12V 15Ah Battery 15 Ah 3.74 x 5.94 x 3.86 inches 9.00 lbs
Mighty Max 12V 15Ah Battery 15 Ah 3.95 x 5.94 x 3.89 inches 9.60 lbs
PowerStar 12V 15Ah Battery 15 Ah 6.6 x 7.13 x 3.00 inches 12.5 lbs
UPG 12V 15Ah Battery 15 Ah 3.95 x 5.94 x 3.89 inches 9.60 lbs
Odyssey PC680 Battery 16 Ah 7.5 x 7.15 x 3 inches 15.4 lbs
ExpertPower 12V 18 Ah Battery 18 Ah 6.57 x 7.12 x 3.03 inches 11.68 lbs
Mighty Max 12V 18Ah Battery 18 Ah 6.57 x 7.13 x 3.01 inches 11.90 lbs

Note: Amazon affiliate links ("Model" column) open in the new windows, feel free to check them for the most up-to-date offers and prices.

The chart lists sealed, spill-proof, and practically maintenance-free lead-acid batteries in the 7-18Ah and 4-15 lbs range. On smaller vessels, larger lead-acid batteries may be used to power fish finders, but such batteries are also heavier.

The following comparison chart lists 12V lithium deep-cycle batteries with their capacity, size and weight:

Model Capacity Size (HxLxW) Weight
ExpertPower EP125 5 Ah 3.54 x 2.76 x 3.98 inches 1.7lbs
Miady LFP6AH 6 Ah 3.54 x 2.75 x 4.33 inches 1.65 lbs
Pionergy 12V6Ah 6 Ah 5.9 x 2.5 x 3.6 inches 2.55 lbs
Talentcell LF4011 6 Ah 3.43 x 2.68 x 3.86 inches 1.61 lbs
ExpertPower EP1210 10 Ah 6 x 2.6 x 3.7 inches 2.7 lbs
ExpertPower EP1212 12 Ah 5.94 x 3.86 x 3.7 inches 3.5 lbs
Ionic IC-12V12-EP4S 12 Ah 5.9 x 3.9 x 3.7 inches 3.5 lbs
Talentcell 12V12Ah 12 Ah 5.9 x 3.94 x 3.74 inches 3.1 lbs
EarthX ETX36C 12.4 Ah 5.9 x 3.4 x 4.5 inches 3.9 lbs
Miady 12V16Ah 16 Ah 5.94 x 3.9 x 3.7 inches 3.97 lbs
Eco-Worthy 12V20Ah 20 Ah 7.1 x 3 x 6.3 inches 4.85 lbs
ExpertPower EP1220 20 Ah 7.1 x 3 x 6.6 inches 5.8 lbs
Talentcell 12V24Ah 24 Ah 7.4 x 3.27 x 7.36 inches 7.05 lbs
Eco-Worthy 12V30Ah 30 Ah 7.1 x 3 x 6.3 inches 7.2 lbs
Flypower 12V40Ah 40 Ah 9.37 x 6.77 x 8.7 inches 11 lbs
Scremower 12V40Ah 40 Ah 9.37 x 6.77 x 7.99 inches 11 lbs
Ampere Time 12V50Ah Plus 50 Ah 7.79 x 6.53 x 6.69 inches 14.3 lbs
Chins 12V50Ah 50 Ah 7.7 x 6.4 x 6.4 inches 13.9 lbs
Eco-Worthy 12V50Ah 50 Ah 8.78 x 5.31 x 7 inches 11.9 lbs
ExpertPower EP1250 50 Ah 7.7 x 6.5 x 6.6 inches 13 lbs

Note: Amazon affiliate links ("Model" column) open in the new windows, feel free to check them for the most up-to-date offers and prices.

The chart lists lithium batteries starting from 5 Ah which weigh just ~1.7 pounds (~0.78 kg) to heavier batteries weighing up to 15 pounds (~6.8 kg), but featuring capacity up to 50Ah!

Of course, there are many more 12V lead-acid and lithium batteries that are suitable as fish finder batteries, but these are the most popular ones.

In order to properly choose "the best" fish finder battery for your needs, it is also good to know few things about fish finder battery types, required currents, and similar.


Fish Finder Battery Types

marine batteries 1There are several types of batteries that can be used for powering fish finders.

Sealed lead-acid (SLA) batteries are commonly used as a deep cycle or dual purpose marine batteries. They operate regardless of their position (except upside-down), they are leakproof, they come in various sizes and shapes and they are rather cheap.

Unfortunately, they are also the heaviest batteries used on boats and kayaks.

Good 7-9Ah/12V SLA (Absorbed Glass Mat - AGM, or Gel-cell) battery weighs between 4-6 pounds (1.8-3 kg), while 18-21Ah/12V battery easily weighs 12-15 pounds (5.4-7 kg).

Personally, I would never recommend flooded lead-acid batteries for use on kayaks and small boats.

Nickel Cadmium (NiCd) batteries are lighter than SLA batteries, can provide insanely high currents, but they are not environment friendly, have strong memory effects, and several other issues. If you need lighter batteries, go for good deep-cycle lithium batteries.

Nickel Metal Hydride (NiMH) batteries provide the same capacity as lead-acid batteries, but for a much lower weight. NiMH batteries can be up to 2-3 times lighter than SLA batteries of the same capacity.

However, such batteries also cost more money and usually require special chargers. Although lighter, NiMH batteries are rarely used as fish finder batteries thanks to the improvements in chemistry and technology of the lithium batteries.

Lithium batteries have no memory effect, can be recharged much faster than lead-acid batteries, they support a much larger number of charging/discharging cycles than other batteries (8-10x more than lead-acid, NiCd, or NiMH), etc.

Lithium batteries must be recharged using lithium battery chargers or smart AGM battery chargers featuring dedicated lithium battery charging modes.

expertpower ep1212 w300px

For example, the ExpertPower EP1212 Deep Cycle LiFePO4 battery weighs only 3.5 pounds and is able to supply 0.23 Amps for at least 50+ hours(!) and 1.5 Amps for almost 8 hours.

Also, such battery is protected by a built-in Battery Management System (BMS) that also balances cells on a regular basis and can withstand at least 2500-7000 charge/discharge cycles depending on the depth of discharge. 

On the other hand, such battery also costs more than similar (in terms of capacity) AGM batteries - lithium batteries initially do cost more, but thanks to their features, in the long run, they actually save the money.

Note: Lithium batteries weighing up to 15 pounds feature capacities up to 50Ah and can be used not only as fish finder batteries but also as general-purpose deep-cycle batteries for powering other devices, including smaller trolling motors, navigation lights, smaller power inverters, etc.


Fish Finder Battery Required Capacity

garmin striker mOne of the first steps in choosing the proper fish finder battery is to determine the required capacity of the battery - required capacity is calculated by multiplying fish finder current (Amperes) and desired operating time (hours) and is given in Ampere-Hours (Ah).

Most fish finders consume around or less than 1 Amp of current when powered from 12V sources. Smaller, portable models draw even less than that, but larger ones, especially fish finder/GPS combos can draw more than that.

For example, one of the most popular, compact, and rather versatile fish finders Garmin Striker 4 GPS Fish Finder (Amazon link, opens in the new window), draws ~0.23 Amps, when being powered with a 12V source.

Just to be sure, let us assume that our hypothetical fish finder draws 1.5 Amps at 12V.

When going fishing from a kayak or similar small boat, fishing trips rarely last more than 10-12h and often are much shorter and last, for example, 3-4 hours. Upon return to the shore or larger boat, the fish finder battery can be recharged.

So, if one prefers longer trips lasting 10-12h, the required theoretical battery capacity is 15 to 18Ah, while for shorter trips (3-4h), the required theoretical capacity is 4.5 - 6 Ah.

In real life, battery capacity is lower than theoretical and hence, larger batteries must be used, depending mostly on the age and condition of the battery.

When buying a new battery for a fish finder, increase capacity by 20-25% - instead of 18Ah (theoretical) for longer trips, consider 21-24Ah batteries and instead of 6Ah batteries for shorter trips, consider 7-9Ah batteries.

And if you use a smaller fish finder with lower power requirements, such batteries can operate much longer on a single battery charge.


Charging Fish Finder Batteries

battery charger small mBatteries in general should be charged using battery chargers designed for specific battery type.

Using wrong chargers can lead to damaged and destroyed batteries and chargers and even to injuries or worse due to possible heat, fire, smoke, and even explosion. And we are serious about this.

SLA batteries are cheap and can be fully charged overnight or even faster, using 'fast' chargers. Note that such fast charging tends to slightly reduce the battery's lifetime.

Using 'fast' chargers, lithium batteries can be charged even under an hour, although charging them for 4-6 hours prolongs their operating lifetime.

When going off-the-grid for longer periods of time, batteries may be recharged using solar panels connected to the charge controllers that support charging lead-acid and/or lithium batteries.

For example, a small 50W solar panel with 50% efficiency (cloudy weather, not under an ideal angle, etc.) may charge the 12V batteries with ~2 Amps, allowing it to recharge the fully discharged 12Ah battery during 6-8 hours of daylight easily.

Again - using wrong chargers can lead to physical damage and injuries caused by high temperature, smoke, fire, explosion ...


Fish Finder Battery Box

marine battey power center mManufacturers of electric trolling motors like Minn Kota, Newport Vessels, and similar, also manufacture battery box power centers. Such power centers are designed to be very robust, water- and dust-proof, and resilient to mechanical damage.

Commonly, power centers accept BCI Group 24 and 27 batteries (60-100 Ah) and feature integrated circuit breakers, USB chargers, battery monitors, 12 V accessory ports, and similar.

Although such battery power centers sound like an 'overkill' for fish finder batteries, they are highly recommended for any longer fishing trip, even when electric trolling motors are not used.

But, if you like to spend every possible free moment fishing from your kayak, put a high-quality battery in your power center box, connect a small solar panel and/or small wind turbine and power your fish finder, GPS, and even small electric trolling motor.

Note: All batteries should be protected from open water, sun, cold wind, etc. Store them in the watertight compartment, low in the boat (to improve stability, especially if you choose a larger AGM SLA battery).


Fish Finder Battery vs Portable Solar Power Station

 Instead of a dedicated fish finder battery, some fishermen carry a medium size portable solar power station combined with a foldable solar panel.

Portable solar power stations feature the built-in high-capacity lithium battery combined with controller (usually MPPT battery charger + inverter) electronics, allowing the user to charge the power station in many ways (for example, using solar panels, wall charger, car 12V port charger) and to power 120V AC, 12V DC, 5V USB devices.

Such portable power stations do cost more than lithium batteries alone, but they also offer much more.

jackery explorer 1000 w300p

For example, Jackery Explorer 1000 (Amazon link, link opens in the new window) portable solar power station features ~1000Wh lithium battery combined with ~85% efficient controller and provides the user with:

- 3x AC 120V 5-20R,

- DC 12V 10A Car port,

- 2x USB-C, USB-A, Quick Charge 3.0 USB port.

Jackery Explorer 1000 weighs 22.1 pounds (~10 kg) and feature physical dimensions of 13.1 x 9.2 x 11.1 inches (~33.3 x 23.4 x 28.2 cm).

Other power stations may also be used to power various fish finders instead of the lead-acid/lithium batteries, just be sure to check the station's battery size/capacity and the output ports.

 


Few Final Words

If You are not sure what to do, go for a cheap and reliable AGM SLA battery, dimensioned for your fish finder. Even 2-3 small, 7Ah/12V batteries with proper charger, cost under $100.

Model Capacity Size (H x L x W) Weight
Chrome Battery 12V 7AH Battery 7 Ah 3.72 x 5.94 x 2.56 inches 4.1 lbs
ExpertPower 12V 7Ah Battery 7 Ah 3.70 x 5.94 x 2.56 inches 4.52 lbs
UPG 12V 7Ah SLA Battery 7 Ah 3.86 x 5.94 x 2.56 inches 4.80 lbs
UPG 12V 8Ah Battery With Charger 8 Ah 3.94 x 5.94 x 2.56 inches 4.96 lbs
UPG 12V 9AH Battery With Charger 9 Ah 4.06 x 5.94 x 2.56 inches 5.17 lbs
ExpertPower 12V 12 Ah Battery 12 Ah 3.9 x 5.94 x 3.86 inches 7.61 lbs
Mighty Max 12V 12Ah Battery 12 Ah 4.00 x 5.94 x 3.88 inches 8.38 lbs
Chrome Battery 12V 15Ah Battery 15 Ah 3.74 x 5.94 x 3.86 inches 9.00 lbs
Mighty Max 12V 15Ah Battery 15 Ah 3.95 x 5.94 x 3.89 inches 9.60 lbs
PowerStar 12V 15Ah Battery 15 Ah 6.6 x 7.13 x 3.00 inches 12.5 lbs
UPG 12V 15Ah Battery 15 Ah 3.95 x 5.94 x 3.89 inches 9.60 lbs
Odyssey PC680 Battery 16 Ah 7.5 x 7.15 x 3 inches 15.4 lbs
ExpertPower 12V 18 Ah Battery 18 Ah 6.57 x 7.12 x 3.03 inches 11.68 lbs
Mighty Max 12V 18Ah Battery 18 Ah 6.57 x 7.13 x 3.01 inches 11.90 lbs

Note: Amazon affiliate links ("Model" column) open in the new windows, feel free to check them for the most up-to-date offers and prices.

Over time, You will figure out your most common practices and You will be able to more accurately define your needs regarding fish finder batteries.

Lithium batteries are much lighter and allow the user to save some weight and in the long run even money.

Model Capacity Size (HxLxW) Weight
ExpertPower EP125 5 Ah 3.54 x 2.76 x 3.98 inches 1.7lbs
Miady LFP6AH 6 Ah 3.54 x 2.75 x 4.33 inches 1.65 lbs
Pionergy 12V6Ah 6 Ah 5.9 x 2.5 x 3.6 inches 2.55 lbs
Talentcell LF4011 6 Ah 3.43 x 2.68 x 3.86 inches 1.61 lbs
ExpertPower EP1210 10 Ah 6 x 2.6 x 3.7 inches 2.7 lbs
ExpertPower EP1212 12 Ah 5.94 x 3.86 x 3.7 inches 3.5 lbs
Ionic IC-12V12-EP4S 12 Ah 5.9 x 3.9 x 3.7 inches 3.5 lbs
Talentcell 12V12Ah 12 Ah 5.9 x 3.94 x 3.74 inches 3.1 lbs
EarthX ETX36C 12.4 Ah 5.9 x 3.4 x 4.5 inches 3.9 lbs
Miady 12V16Ah 16 Ah 5.94 x 3.9 x 3.7 inches 3.97 lbs
Eco-Worthy 12V20Ah 20 Ah 7.1 x 3 x 6.3 inches 4.85 lbs
ExpertPower EP1220 20 Ah 7.1 x 3 x 6.6 inches 5.8 lbs
Talentcell 12V24Ah 24 Ah 7.4 x 3.27 x 7.36 inches 7.05 lbs
Eco-Worthy 12V30Ah 30 Ah 7.1 x 3 x 6.3 inches 7.2 lbs
Flypower 12V40Ah 40 Ah 9.37 x 6.77 x 8.7 inches 11 lbs
Scremower 12V40Ah 40 Ah 9.37 x 6.77 x 7.99 inches 11 lbs
Ampere Time 12V50Ah Plus 50 Ah 7.79 x 6.53 x 6.69 inches 14.3 lbs
Chins 12V50Ah 50 Ah 7.7 x 6.4 x 6.4 inches 13.9 lbs
Eco-Worthy 12V50Ah 50 Ah 8.78 x 5.31 x 7 inches 11.9 lbs
ExpertPower EP1250 50 Ah 7.7 x 6.5 x 6.6 inches 13 lbs

Note: Amazon affiliate links ("Model" column) open in the new windows, feel free to check them for the most up-to-date offers and prices.

While 13-15 lbs AGM batteries are able to power 12V 1.5 Amps devices up to 10 hours (some charge left since lead-acid batteries last much longer when not regularly discharged down to 100% DoD), similar 13-15 lbs lithium batteries are able to power such 12V 1.5 Amps devices 30+ hours easily.

Also, power stations being able to store 1000 Wh of energy (like Jackery Explorer 1000) can power 12V 1.5 Amps devices for 40-45 or even more hours, depending on the battery condition and initial charge.

Note: not all power stations support the so-called pass-through charging - such power stations may be charged (for example, using solar panel) while in use (for example, while powering fish finder).

But, whatever You do, stay safe, although small, these batteries can provide surprisingly large currents and cause damage, injuries, or worse ...



Recommend This Page

Search Deep Cycle Marine Battery


Go to Top