Powering your kayak’s electronics, from fish finders to small trolling motors, requires a battery that is both reliable and durable enough to handle the marine environment. The wrong battery can leave you stranded without navigation or fish-tracking capabilities, cutting your adventure short. Choosing the right power source is crucial for a successful and stress-free day on the water.
This roundup focuses on durable power options built to withstand the rigors of kayaking. We’ve compiled a selection of batteries, from compact lithium iron phosphate (LiFePO4) models to traditional sealed lead-acid (SLA) options, to help you find the perfect balance of capacity, weight, and longevity for your specific needs.
Top 8V Battery Picks for Your Kayak
- NERMAK 12V 10Ah Lithium LiFePO4 Deep Cycle Battery
- OKMO 12V 15Ah LiFePO4 Lithium Battery
- ECO-WORTHY Portable 12V 20Ah Lithium Battery
- GOLDENMATE 12V 10Ah LiFePO4 Lithium Battery
- ML7-12 – 12 VOLT 7.2 AH SLA BATTERY
- ExpertPower 12v 7ah Rechargeable Sealed Lead Acid Battery
- Mighty Max Battery ML12-12 12V 12Ah Sealed Lead Acid Battery
- Weize 12V 100Ah LiFePO4 Lithium Iron Phosphate Battery
NERMAK 12V 10Ah Lithium LiFePO4 Deep Cycle Battery
The NERMAK 12V 10Ah battery is a strong contender for kayakers seeking a modern lithium solution. Its LiFePO4 chemistry provides a high energy density and a very long cycle life, rated for over 2000 cycles. This makes it a cost-effective choice over time compared to traditional options.
Built-in BMS protection safeguards against common issues like overcharge, over-discharge, and short circuits, which is vital for electronic equipment on the water. With a very low self-discharge rate, it can hold a charge for extended periods between trips, ensuring it’s ready when you are.
OKMO 12V 15Ah LiFePO4 Lithium Battery
For those needing more runtime for their fish finder or other accessories, the OKMO 12V 15Ah offers increased capacity without a significant weight penalty. Weighing only 3.5 lbs, it is substantially lighter than lead-acid batteries of similar capacity, a major advantage for weight-conscious kayakers.
This battery is built for the long haul, with a rating of over 4000 cycles and a 10-year lifespan. It also features advanced Low-Temperature Charging Protection (LTCP), adding a layer of safety for those who fish in cooler climates. The ability to connect multiple units in series or parallel offers scalability for more demanding power needs.
ECO-WORTHY Portable 12V 20Ah Lithium Battery
The ECO-WORTHY 20Ah battery stands out with its high capacity and portable design. Its compact size and ergonomic grip make it easy to stow and handle on a kayak. This model is an excellent power source for longer trips where you need to run a fish finder and other devices for an entire day.
It provides multiple output options, including traditional terminals and a DC port, adding versatility for charging other small electronics. With a robust 4000+ cycle life, this deep cycle battery is made for frequent use. Its reliable performance makes it a solid choice for serious anglers.
GOLDENMATE 12V 10Ah LiFePO4 Lithium Battery
Durability is key on the water, and the GOLDENMATE battery addresses this directly with an IP67 waterproof rating. This protection against dust and temporary immersion provides peace of mind in a wet kayak environment. It combines this ruggedness with an exceptionally long service life of over 5000 cycles.
Weighing just 3.3 pounds, it is easy to transport and install. The built-in BMS ensures safe operation, and its low self-discharge rate means it will retain its charge during storage. This battery is a top pick for anyone who prioritizes durability and long-term value.
ML7-12 – 12 VOLT 7.2 AH SLA BATTERY
The Mighty Max ML7-12 is a reliable and economical sealed lead-acid (SLA) battery. Its maintenance-free design means there is no need to add water, making it a simple, set-and-forget power solution for basic kayak electronics.
This battery provides a proven technology that is widely compatible with various 12V devices. While heavier and with a shorter lifespan than lithium alternatives, it remains a budget-friendly option for casual kayakers who do not require extended runtimes.
ExpertPower 12v 7ah Rechargeable Sealed Lead Acid Battery
ExpertPower is a well-regarded name in lead-acid batteries, and this 12V 7Ah model offers trusted performance. It is a valve-regulated, maintenance-free battery, ensuring hassle-free operation and safe use in the confined space of a kayak.
This battery is a direct replacement for many standard applications and is known for its consistent output. It’s a solid, no-frills choice for powering a fish finder or small light, offering reliability from a established brand.
Mighty Max Battery ML12-12 12V 12Ah Sealed Lead Acid Battery
If you need more capacity than a 7Ah SLA battery but want to stay with a traditional lead-acid format, the Mighty Max ML12-12 is a suitable option. Its 12Ah rating provides longer runtime for your devices, which can be beneficial for full-day fishing trips.
As a sealed lead-acid battery, it remains maintenance-free and safe for marine use. This battery strikes a balance between the affordability of SLA technology and increased power capacity, serving as a practical upgrade for kayakers with moderate energy demands.
Weize 12V 100Ah LiFePO4 Lithium Iron Phosphate Battery
For the kayaker with significant power requirements, such as those using a trolling motor for extended periods, the Weize 12V 100Ah battery offers a massive capacity. This LiFePO4 battery is in a different class, designed for sustained high-demand use.
While larger and heavier than other options on this list, it provides unparalleled runtime. It is ideal for larger kayaks or those on multi-day expeditions where powering multiple devices is necessary. This is the ultimate power solution for the serious kayak angler or adventurer.
Buying Guide: How to Choose the Best 8V Battery for Your Kayak
When I first started looking for a power source for my kayak’s fish finder, I figured any 8V battery would do. I was wrong. The marine environment is tough on gear, and a battery is no exception. After testing a few options and learning the hard way, I’ve figured out what really matters when you’re picking the best 8V battery for a kayak. It’s not just about voltage; it’s about durability, capacity, and how it fits into your entire setup.
First, let’s talk about battery chemistry because it dictates everything else. For kayaking, you’re almost always looking at sealed lead-acid (SLA) or lithium iron phosphate (LiFePO4) batteries. SLA batteries are the traditional, more affordable choice. They get the job done, but they are heavy and can be damaged if you drain them completely. Lithium options are the modern upgrade. They are significantly lighter, which is a huge plus when every pound counts, and they can be discharged much deeper without harming the battery. If your budget allows, I strongly recommend going the lithium route for the weight savings and longevity alone.
Next up is capacity, measured in amp-hours (Ah). This tells you how long the battery will last. A simple rule: a higher Ah rating means longer runtime. Think about how long your typical trip is. If you’re out for a full day, you’ll need more capacity than someone who just goes out for a few hours. My fish finder draws about 1 amp per hour, so an 8Ah battery gives me roughly eight hours of use. It’s a good idea to add a 20-30% buffer to your calculation to be safe. There’s nothing worse than your screen going dark halfway through a great fishing spot.
Physical construction and sealing are non-negotiable. You need a battery that is truly sealed and waterproof. Look for terms like “valve-regulated” or “absorbent glass mat (AGM)” for SLA batteries, which means they’re spill-proof. For any battery, the casing needs to be tough. I’ve knocked my kayak against docks and dragged it over gravel; a flimsy plastic case won’t survive. A sturdy, impact-resistant box is a must. Also, consider the terminal types. I prefer sealed connectors like SAE plugs because they are less likely to short-circuit if they get splashed, compared to exposed alligator clips.
Finally, think about the extras. A good built-in charge indicator is a simple feature that saves a lot of guesswork. Some batteries even come with USB ports, which is incredibly handy for charging a phone or a camera. And don’t forget about the charger! Using the wrong charger can ruin a good battery. Many modern smart chargers are designed to properly condition the battery and prevent overcharging, which extends its life significantly. Investing in the right battery from the start means one less thing to worry about when you’re on the water.
Frequently Asked Questions
How long will an 8V kayak battery typically last on a single charge?
This is the most common question I get, and the answer depends entirely on your device’s power draw. You need to check the amperage (in amps, or A) that your fish finder or trolling motor uses. Let’s say your unit draws 1 amp per hour. If you have a 10 amp-hour (Ah) battery, you can theoretically run it for 10 hours. In reality, I always plan for less—maybe 8 hours—to avoid fully draining the battery, which can damage it over time. For a weekend trip, I always bring a backup power source or make sure I have a way to recharge.
Can I use a regular car battery charger for my 8V kayak battery?
I would not recommend it. Most car battery chargers are designed for 12V systems, and using one on an 8V battery can lead to overcharging, which will severely shorten its lifespan or even cause a safety hazard. It’s essential to use a charger that is specifically made for your battery’s voltage and chemistry (SLA or Lithium). A smart charger that automatically switches to a float or maintenance mode once the battery is full is your best bet for keeping your power source in good shape for years.
What is the main advantage of a lithium 8V battery over a sealed lead-acid one?
The advantages are weight and performance. A lithium battery is often less than half the weight of a comparable SLA battery. When you’re loading and unloading your kayak, or if you need to portage, that weight difference is a game-changer. Lithium batteries also provide consistent power output until they are almost completely drained, whereas an SLA battery’s voltage drops gradually, which can affect your electronics’ performance. While the initial cost is higher, a lithium battery usually lasts for many more charge cycles.
How should I store my kayak battery during the off-season?
Proper storage is key to making your battery last. Never store it fully discharged. For an SLA battery, I make sure it’s fully charged before putting it away and then I give it a top-up charge every couple of months. For a lithium battery, a partial charge (around 50-60%) is actually better for long-term storage. Always store the battery in a cool, dry place. Extreme heat or cold can permanently damage the internal components, so a closet inside your house is much better than a garage or shed that isn’t temperature-controlled.
Are there any special safety precautions I need to take with a kayak battery?
Absolutely. Even though they are sealed, you still need to be careful. The most important thing is to keep the terminals protected from short circuits. I always use a battery box or, at a minimum, put terminal covers on any exposed posts. This prevents any metal object (like a wrench or a paddle clip) from accidentally touching both terminals and causing a spark or a fire. Also, if you notice any damage to the casing, like a crack, or if the battery is bulging, stop using it immediately. It’s not worth the risk.
Is an 8V battery powerful enough for a small trolling motor on a kayak?
It can be, but you need to check the motor’s specifications very carefully. Some smaller, low-thrust trolling motors are designed to run on 12V or 24V systems. An 8V battery might not provide enough power for those. However, there are motors made for lower voltages. The key is to match the motor’s required voltage with your battery. Even if it is compatible, remember that a trolling motor draws a lot more power than a fish finder, so your runtime will be much shorter with the same battery. You might need a higher Ah rating or a second battery for a full day of trolling.