The best deep cycle marine battery for boat is the essential to power all the electronic appliances and trolling motor in the boat. Marines batteries are available in many shapes and types as you can find in this link, However, one of the problem when I first researching for marine batteries is that most of them are expensive.
If you are looking for a deep cycle battery for your boat with the limit budget, you should look on this list of affordable and good performance marine batteries. Here also has some good deep cycle batteries for boats.
#1 Mighty Max Battery ML35-12 – 12V 35AH DEEP Cycle SLA Battery
It is not easy to fine the other battery that is under $70 price but still offer the great performance like this Mighty Max ML35-12 deep cycle battery. It is designed with small capacity of only 35Ah, what makes it is ideal for small boats with light-trolling capacities. With the dimensions 5.16 x 7.68 x 7.13 inches and weighs just 23.25 pounds, this battery fit perfectly in small room and does not take lots of space in boats, kayaks and canoes.
You do not need to worry if this batteries compatible with your boat or not, because it comes with many applications and there is nothing complicate to install this battery. This AGM battery also does not require you lots of maintenance. If you need the battery with higher capacity, you can wire two Mighty Max ML35-12 batteries to get 70 amp hours with a very affordable price tag. Although it is fairly cheap but it still ensure the benefits of AGM batteries such as low maintenance and leak-proof.
#2 Universal Power Group 12V 100Ah Solar Wind AGM SLA DEEP Cycle VRLA Battery
This battery is more expensive than the Mighty Max model but $180 for a reliable, quality marine battery is still relatively affordable. Universal Power Group 12V Deep Cycle Battery is the versatile and effective marine battery that will provide enough power for the entire electric system in your boat with fast and reliable performance. This battery does not require any maintenance.
The UPG battery provides 100Ah capacity and can run continuously for about 120 minutes. In the case if you do not use the battery regularly, it can hold its charge for up to 6 months. This battery is affordable but it provides a remarkably efficient that can run most high-power electrical appliances. What I like most about UPG battery is that it is very versatile that not only be used for boat but also can be used for camping trip, and home setups as well. It also is connected with the other UPG battery to become makeshift generator at home.
The downside of the UPG is that it is a bit heavy, what makes it not really convenient. But it is pretty compact. Besides, it has sharp geometric corners, this can be a tricky when maintain the battery. The handle of the battery is a single cord, this is not the ideal handle for the heavy battery like this one. It is just a few problems with the UPG’s design, but this is still the battery that worth the purchase. It also offers you a 1-year warranty.
#3 Interstate Batteries 12V 35AH Sealed Lead Acid (SLA) AGM Deep Cycle Battery
Last but not least, Interstate Batteries 12V 35AH Sealed Lead Acid battery is the high longevity and reliable power source for boat engine and other electrical appliances. What I like most about this battery is that it is extremely lightweight, easy to install and storage .
The Interstate Deep Cycle will ensure your boat’s trolling motor has enough power to operate for a full day on the water. It features metal plates, which allow it charge quickly. As the name suggested, this battery is sealed lead acid, that means it is leak and water proof, it does not require any maintenance. You just need to ensure that the leads are always clean and never completely discharges.
Interstate Deep Cycle Battery have been put in a rigorous 7-point quality control test and if there is any error from the manufacturer, you will have one-year warranty for this product. The downside is that it is a bit lower reserve capacity than some other batteries.