Battery Equivalents and Replacements

The Best Fish Finder Batteries for Kayaks and Smaller Boats

Fish finder batteries for kayaks and smaller boats must be lightweight and compact, but accept charge quickly from various sources, and should be able to power the fish finder during the entire fishing session without the need to be recharged before going to shore or starting the main engine (if present).

Fish finder batteries are spill-proof AGM and Gel-Cell lead-acid batteries and Lithium Iron Phosphate (LiFePO4) batteries. Most fish finder batteries feature nominal capacity in the 5 - 20 Ah range.

Published: February 24, 2021.

mighty max ml12 12 w300px

Fish Finder Battery Required Features

Fishing trips with smaller boats and kayaks that sometimes last even for days or even weeks are getting more and more popular and they all have one common feature - lack of storage space and limited payload.

Even ocean-going fishing kayaks have limited payload and when going for longer fishing trips, every pound counts.

Thus main features of goof fish finder batteries include spill-proof, compact and lightweight design, high capacity, easy charging, reliable power source, compatibility with other equipment as well, maintenance-free operation, acceptable price, and similar.

Basically, fish finder batteries may be Sealed Lead-Acid (SLA) batteries or Lithium Iron Phosphate (LiFePO4) batteries.

Sealed Lead-Acid (SLA) batteries may be either Gel-Cell or Absorbent Glass Mat (AGM) batteries, with AGM batteries being more common - both Gel-Cell and AGM batteries are maintenance-free batteries, designed to be vibration resistant and to be spill-proof. Most of them may operate in any position, except upside-down, with some models being able to normally operate even upside-down.

The number of charging/discharging cycles depends on the Depth of Discharge (DoD) and when the batteries are discharged down to 100% DoD, they tolerate 170-200 charging/discharging cycles and 300-400 cycles down to 50%, with some premium models being able to withstand 600-800 cycles down to 50% DoD.

AGM and Gel-Cell batteries are easily charged with smart AGM battery chargers - such battery chargers may even analyze the battery first and then charge it depending on the battery condition, with equalization and maintenance charging modes being the last ones.

Also, AGM and Gel-Cell batteries are fairly cheap.

expertpower ep1210 w250On the other hand, Lithium Iron Phosphate (LiFePO4) batteries cost more than lead-acid batteries and should be charged only with the battery chargers intended for such batteries. Some advanced AGM battery chargers feature special charging mode intended for lithium batteries.

Note: If you don't have a lithium battery charger, don't charge your lithium battery with a common lead-acid battery charger - it may overheat and burst to flames or even explode. Most lithium batteries do have Battery Management Systems (BMS) that protect the batteries from unwanted events like overcharging, over-discharging, overtemperature, short-circuit, and similar, but better safe than sorry.

Lithium batteries are 2-3 times lighter than lead-acid batteries considering 20h capacity, and with the increase of discharge current, this ratio is even larger, up to 4-5 times.

Also, lithium batteries tolerate a much larger number of charging/discharging cycles, with some models easily withstanding 2000-3000 charging/discharging cycles down to 100% DoD, 5000-6000 cycles down to 80% DoD, etc.

Initially, lithium batteries cost more, but in the long run, they are both cheaper and great weight savers, which can be very important for applications where payload weight is rather limited.

Fish Finder Battery Power Requirements

Fish finder batteries feature nominal voltage of 12 volts and nominal capacity usually in the 5 to 20Ah range, with some vessels being able to carry even larger batteries, that are often used as general-purpose batteries for powering fish finder, navigation lights, smaller trolling motor and similar.

Power requirements of most popular fish finders on the market differ greatly and are usually in the 0.2 and 2 Amps range, with some larger models requiring even more than 2 Amps.

For example, if You need the battery for Garmin Striker 4 with the runtime between recharges of at least 10h, You will need a rather small battery - even 5Ah battery is able to power such unit for a day. If the weight savings are important, then consider taking lithium battery in the 2.5-3 Ah range.

On the other hand, if You have a larger unit that requires 2 Amps to operate properly for at least 8 hours, consider larger 20Ah AGM (~12-13 pounds) or lithium (~6 pounds) battery.

The following comparison chart lists some of the most popular AGM and lithium batteries suitable as fish finder batteries:

Model Battery Type Capacity Size (L x W x H) Weight
ExpertPower EP125 LiFePO4 5 Ah 3.54 x 2.76 x 3.98 inches 1.6 lbs
Mighty Max ML5-12 AGM 5 Ah 3.54 x 2.75 x 4.21 inches 3.09 lbs
Miady LFP6Ah LiFePO4 6 Ah (5h) 2.75 x 4.33 x 3.54 inches 1.65 lbs
Chrome 12V 7Ah Battery AGM 7 Ah 5.94 x 2.56 x 3.72 inches 4.1 lbs
Dakota CR12V7Ah LiFePO4 7 Ah 5.94 x 2.55 x 3.74 inches 2.15 lbs
ExpetPower EXP1270 AGM 7 Ah 5.94 x 2.56 x 3.70 inches 4.52 lbs
UPG UB1270 AGM 7 Ah 5.94 x 2.56 x 3.86 inches 4.80 lbs
Odyssey PC310 AGM 8 Ah 5.43 x 3.90 x 3.98 inches 5.9 lbs
UPG UB1280 AGM 8 Ah 5.94 x 2.56 x 3.94 inches 4.96 lbs
Mighty Max ML9-12 AGM 9 Ah 5.94 x 2.56 x 3.94 inches 5.44 lbs
UPG UB1290 AGM 9 Ah 5.94 x 2.56 x 4.06 inches 5.17 lbs
Dakota CR12V10Ah LiFePO4 10 Ah 5.94 x 2.55 x 3.74 inches 2.9 lbs
ExpertPower EP1210 LiFePO4 10 Ah 6 x 2.6 x 3.7 inches 2.7 lbs
Chrome 12V 12Ah Battery AGM 12 Ah 5.94 x 3.86 x 3.74 inches 7.27 lbs
Mighty Max ML12-12 AGM 12 Ah 5.94 x 3.88 x 4.00 inches 8.38 lbs
TalentCell LF120A1 LiFePO4 12 Ah 5.91 x 2.72 x 3.67 inches 2.98 lbs
Weize FP12120 AGM 12 Ah 5.94 x 3.86 x 3.98 inches 8.15 lbs
EarthX ETX36C LiFePO4 12.4 Ah (1h) 5.91 x 3.38 x 4.53 inches 3.9 lbs
Odyssey PC545 AGM 13 Ah 7.01 x 3.38 x 5.16 inches 11.4 lbs
Odyssey PC535 AGM 14 Ah 6.70 x 3.90 x 6.24 inches 12.0 lbs
Chrome 12V 15Ah Battery AGM 15 Ah 5.94 x 3.86 x 3.74 inches 9.00 lbs
Mighty Max ML15-12 AGM 15 Ah 5.94 x 3.89 x 3.95 inches 9.60 lbs
PowerStar PS12-15 AGM 15 Ah 7.13 x 3.00 x 6.6 inches 12.5 lbs
UPG UB12150 AGM 15 Ah 5.94 x 3.89 x 3.94 inches 9.20 lbs
Odyssey PC680 AGM 16 Ah 7.15 x 3 x 7.5 inches 15.4 lbs
ExpertPower EXP12180 AGM 18 Ah 7.12 x 3.03 x 6.57 inches 11.68 lbs
Mighty Max ML18-12 AGM 18 Ah 7.13 x 3.01 x 6.57 inches 11.90 lbs
Odyssey PC625 AGM 18 Ah 6.70 x 3.90 x 6.95 inches 13.2 lbs
ExpertPower EP1220 LiFePO4 20 Ah 7.1 x 3 x 6.6 inches 5.8 lbs
ExpertPower EXP12200 AGM 20 Ah 7.13 x 3.03 x 6.57 inches 12.5 lbs
Weize FP12200 AGM 20 Ah 7.13 x 3.03 x 6.57 inches 12.28 lbs

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

When choosing the right fish finder battery, choose according to your own needs and requirements - it is not the same if you have a weight limit or budget limit. Or both.

In the end, whatever You do, be sure to stay safe.