A fish finder is one of the best tools you can use as an angler. It takes a lot of the guesswork out of your job. But if you want your fish finder to live up to its potential, you need power. That means choosing the right battery. Let’s take a look at which batteries can stand up to the task.

Expert Power 12v 10Ah Lithium Ion Battery

Expert Power’s lithium ion battery is top of the line. If you’ve only used cheaper SLA batteries in the past, this will blow you away. You will get at least twice as much life out of this lithium iron phosphate battery. Potentially you’re looking at up to three times. Between 2500 cycles and 7000 cycles means this battery can stand up to use. Depending on the SLA battery you compare it to, this offers more than 10 times the charges. Up to 15 even.

The company offers you a 10 year guarantee to remove any doubts. When’s the last time you had a battery guaranteed for 10 years? An SLA battery literally cannot last that long. The trade off is, of course, price. The 10Ah model comes in at around three times the price of many decent SLA batteries. That can be intimidating. Especially if you don’t use it often, right? But if you want reliable power, this is a great choice.

With the power output, you can probably take this battery out more than once on a single charge. We don’t recommend that, though. We always recommend making sure everything is fully charged before every trip. Because you never know, right? But the fact is this little battery could potentially handle it. And it weighs under three pounds! That means this is ideal for any bass boat and even a kayak.

Expert Power also has a Battery Management System. That protects the battery from overcharging, full discharge, short circuits, overheating, and more. They charge quickly and take up minimal space. Pound for pound, these are the best fish finder batteries on the market.

Ampere Time 12v 50Ah Battery

Ampere Time’s 12V 50Ah battery is no joke. The company provides a 5-year warranty on the battery. If customer service can’t solve your battery issue, they’ll give you a new one. Or you get your money back. That’s a pretty solid offer that you won’t see from most companies.

The Ampere Time battery is definitely at the highest end of the price range. But don’t forget that 50Ah rating. This battery is going to give you a lot of power for a long time. At 14.3 pounds this is a fraction of what SLA batteries would weigh for the same power. In fact, you’d probably need a couple of SLA’s to meet the performance here.

The battery has a 4000+ cycle life which means you can recharge it again and again. The company says 10 years but your mileage may vary, of course. It operates at 95% efficiency for most of its life thanks to a flat discharge curve. The load power is 640 Watts.

It’s designed to operate from O degrees Celsius up to 50 degrees. So from freezing to well over the hottest day you’re likely to experience. Keep that low temperature in mind if you boat in colder climates. You do not want to take this below freezing or it will be damaged.

It’s waterproof and vibration resistant. It’s also protected from overcharge, short circuit, overheating, and over discharge. With the power provided you should be more than able to handle a fish finder and a few other components as well.

If you need serious power for the long haul, this is the best fish finder battery for you.

Dakota Lithium 12V 7Ah Battery

Dakota’s batteries are top notch and affordable. This is our pick for a budget battery not because it’s lower quality than the others. As you can see, at 7Ah this is designed to simply be a smaller, more efficient battery. And the price reflects that. For a lithium ion battery, you won’t find a better mix of price and quality.

At 2000 charge cycles, this is a seriously long-lived powerhouse. Best of all, it weighs just barely over 2 lbs. You can fit this little guy anywhere. If you’re looking to set up your kayak with a fish finder, you won’t find a better option. It’s durable, portable, and powerful.

Dakota offers an incredible 11 year warranty. It charges quickly and features a battery management system. Like the bigger batteries, it’s protected against a lot. That includes over charging, high temps, and short circuits.

The big selling point for Dakota is just how durable it is. Some batteries simply cannot handle freezing temperatures. Well, they don’t call this a Dakota for nothing. This can handle down to -20F. Max temp is up at 120F. They do recommend not charging it below freezing though, so keep that in mind. You can use it that low, just don’t charge it again until you get it somewhere warmer.

Expert Power 12V 7Ah SLA 2 Pack

If you want to stick with SLA batteries, Expert Power is where you want to look first. Their 12V 7Ah SLA’s are a great price. You’ll see these in home security systems and even mobility scooters. They work just as well in fish finders and provide long lasting, reliable power.

Because they’re SLA, they do take a bit longer to recharge than a lithium battery. Expect about 4 hours to reach a full charge. They also have a standby lifespan of around 3 to 5 years.

It’s hard to tell in pictures, but these are real space savers as far as batteries go. They’re under 6 inches long and 4 inches high. That means finding a place to store them is no issue at all.

You can buy these in a double pack so it’s easy to swap one out and use the other. That extends your fish finder lifespan considerably. And at barely any more cost to storage. And for the money, it’s a great deal. Two batteries for only a fraction of what a similar lithium battery would cost. The lifespan isn’t as long as a lithium, of course. But if you need something in a hurry that’s cheap and reliable, these are great.

These are sold as replacement batteries. If you don’t have an SLA charger already, you’ll need one. Just make sure it’s for SLA and not lithium battery charger. Look for something like smart AGM battery chargers.

Mighty Max 12V 15Ah SLA Battery

At just under six inches by four inches, the Mighty Max 12V 15Ah is small but solid. Take this on the jon boat to power your fish finder and you’ll be good to go all day. It still weighs over 5 lbs so keep that in mind. It’s chunky, but it won’t take a ton of space. You can still make good use of this on something as small as a canoe.

They’re designed to be mounted in almost any position, which can really come in handy. Upside down is not a good idea, mind you. The downside is you’re on your own getting that done yourself. The battery doesn’t come with any mounting hardware. You’ll have to rig up something for yourself. But it’s worth noting that this fits nicely into something like a Plano ammo box. You can make your own battery box if you want a project for an afternoon.

Because of how they’re designed, these are virtually spill proof. Aside from serious physical damage to the case, it should hold up no matter what.

Universal Power Group 12V 35 Ah Lead Acid Batteries

If you’re looking for good power at a good price, this is a solid option. Universal Power Group’s 12V 35Ah batteries last a long time and won’t break the bank. A lot of kayakers will use this for a fish finder and a motor. The output is reliable enough to handle several components at once.

If you need more than a typical SLA battery, this is a great choice. It’s not a full size deep cycle battery, but it could be all you need. Designed with absorbent glass material, this is a tough battery. It’s made to withstand serious use without breaking. Unlike some SLA batteries, this one won’t leak, either.

ECI Power 12V 20Ah Lithium Battery

ECI Power bridges the gap between the smaller and larger capacity batteries. If you don’t want to go all out with a massive battery, but something like 10Ah isn’t cutting it, try this. The 20Ah battery capacity ensures a decent power output for fish finders and more.

Made in California, these are backed by solid engineering and customer service. They’re made by Expert Power. You’re getting 2000 charge cycles from this battery and a 10 year lifespan. The battery management system protects from overcharge and temperatures. That includes a built in charge cut off if you drop below 23F. Remember, charging a battery in subzero temperatures can effectively destroy the battery. Thanks to the technology here you won’t have to worry about tossing it out and buying a new one.

Things to Remember About Fish Finder Batteries

It’s not enough to just look at one battery and see that it’s a better price than another. There are some technical aspects to consider with a rechargeable maintenance free battery. Let’s take a look at things you should consider before buying a fish finder battery.

Volts vs Amp Hours

When you’re buying fish finder batteries they’re going to show you 2 specific numbers. The volts represented by the letter V. And the amp hours represented by the letters Ah. Understanding what those numbers mean make sure you get the right battery.

Volts: The voltage is a measurement of difference in potential. It measures the electromotive force of a battery. 1 vols is the difference in potential needed to make one ampere of current flow from the battery through a wire. So what the heck is an ampere?

Ampere: Amperes, usually shortened to amps, measure electrical currents. Specifically, it is the rate of electron flow through a circuit.

Ampere Hour: An ampere hour or Ah is how much electricity the battery can store inside of it. It’s listed in a practical manner. The number lets you know how many hours before the current inside the battery will discharge.

A typical fish finder battery may be 12V 10Ah. This means that the battery has 12 volts. You can expect it to last for about 10 hours at that voltage. The higher the ampere hours, the longer your battery will last. So, in general, you want higher numbers. But higher numbers also mean bigger batteries. So it’s a balancing act between what you want and the space you have.

Other Terms to Know

Watts: Watts are the units that measure electrical power stored in the battery. You can get this by multiplying amps by volts.

Cycle Life: This is another important thing to look into when buying fish finder batteries. The cycle life is basically how many times you can drain and then recharge your battery. Every time you recharge your battery it’s going to be a tiny bit less effective than it used to be. The cycle life is how many times you can charge and recharge it. That is before it’s about a 80% less effective than when it started

Which Fish Finder Battery is Right For You?

Picking the right battery needs understanding how much you need it to do. A fish finder will use about 1 amp per hour when you have a 12 volt battery. Multiply the amps in the battery by how long you need it to run.

Some smaller fish finder batteries will offer up about 7 amp hours. Bigger ones could get up to 10 amp hours or more. Some of the most powerful offer as much as 18 amp hours. As long as you have the room for a battery that size, you can be fishing all day.

What is a Kayak Fish Finder Battery?

If you’ve been researching fish finder batteries you’ve probably seen several kinds. You may have run across the term kayak fish finder battery. Is there a difference between any old fish finder battery and a kayak battery? Yes and no.

The difference between a kayak fish finder battery and a regular fish finder battery is size. Consider the difference between a kayak and a fishing boat that can hold five people. A kayak is a smaller boat with less space. So if you’re using the fish finder you need it to take up less space. That means you want the battery to take up less space.

When someone is advertising a battery for kayak fish finder, what they mean is a small battery. Ideally, a kayak one will be compact. That’s obviously important for kayak fishing, right? Compared to a battery that you can use on a larger boat, at least. Some kayak fish finder batteries are still pretty powerful. Depending on the kind of angler you are, you could use these on a bigger boat. Also, depending on how you fish from a kayak, maybe a bigger battery works there too. It all depends on your needs and how you fish. And especially what you have room for.

Lithium Batteries vs a Sealed Lead Acid Battery

There are two kinds of fish finder batteries that you can buy. That’s lithium batteries and SL A batteries. An SLA battery stands for sealed lead acid batteries. SLA batteries are the older kind of battery. These are more easy to find in stores. They also tend to be cheaper. The trade-off is that they are often bigger, but not necessarily always. SLE batteries are the same kind of batteries that most cars run on. These are a good option because they are reliable. There’s a reason they’ve been around for so long, after all. And because they’re cheaper, they’re often more attractive to buyers.

A lithium fish finder battery usually offered greater power. However, lithium ion batteries also tend to be more expensive. However, because lithium batteries tend to perform better, they’re often preferred. lithium batteries offer more power, as well as a greater battery life. There electrical capacity is higher as well. Probably you would only choose an SLA battery over a lithium battery if it came down to the issue of money. Sometimes that will be the deciding factor, and an SLE battery should get the job done for you pretty well.

Benefits of a Lithium Battery

Let’s take a closer look at why a lithium battery is often a better choice for your fish finder battery.

  • One of the most attractive selling points for lithium batteries is charging times. Lithium batteries are the same kind of batteries that are in the phones. You can charge a lithium battery from completely discharged to full pretty quickly.
  • Lithium batteries are much smaller than SLA batteries. This makes it ideal as kayak fish finder batteries. But even in general, they’re just not as clunky. If you’ve ever had to lift a car battery before, you know it’s a bit of a workout. A lithium battery has a greatly reduced size.
  • The cycle life of a lithium battery is superior to an SLA battery. You could get a significantly greater number of charges from a lithium battery.
  • Another important feature of lithium batteries is the flat voltage curve. That means that there’s no drop-off in power as the battery begins to discharge. older batteries have a tendency of offering less power as they begin to die. One of the best visual representations of this is a car that had its headlights left on. The lights will be significantly dimmer as the battery dies out. Or, an old audio cassette playing radio. As the batteries died the cassette real would spend much more slowly. The music would sound like it was coming in slow motion. That was a result of the battery that does not have a flat voltage carrier. When you use a lithium battery, you get the same amount of power until the battery is completely drained. There will be no drop-off in performance.

The Bottom Line

Choosing the right battery for your fish finder takes some time. You want the right price and also the right power output. And depending on your boat, space can be a big consideration as well. Remember to keep your battery well-charged. Also keep it out of those extreme temperatures. And never charge your fish finder battery in the freezing cold.

Stay safe and have fun!