This article was originally published in Midwest Outdoors.
For clarification this article will cover deep cycle batteries and choosing a battery for your boat. With the many different types of deep cycle power on the market today I get a lot of questions about which one would be the best choice. My answer to the question always begins with a question. “So, what are you needing it for and how often will you be using it?” The answer to this question runs the gamut. It is the deciding factor in choosing the best deep cycle battery for their application. Here are a few of the scenarios and the answers to them when deciding between lead acid, AGM and Lithium deep cycle battery.
Weekend Fair Weather Angler
If you’re one of the many anglers that fish when the weather is nice. If you avoid the hot summers and the cold winters, then a lead acid deep cycle boat battery is probably the best choice when choosing the best battery for your boat. The limited number of times you will discharge your deep cycle boat batteries make lead acid a good battery for your boat. Lead acid batteries are easy to charge. They will give you plenty of cycles if you don’t discharge your lead acid battery too far. I have had lead acid batteries last 5 years and I fish a lot. I do make sure to plug in the charger/maintainer as soon as I get home. It is important to get the battery charged fully as quick as possible.
If you are an avid angler and use your fish finders to locate fish and mark fish, then the AGM absorbed glass mat battery might be the best choice. Fishing all day and running the electronics most of that day can put a strain on your boat battery. Lithium is also a good choice. However, the lower upfront cost of the AGM deep cycle battery makes more sense. This is if your depth of discharge or DOD is no more than 50%. Keep the DOD at 50% or less and the lifespan of the AGM battery is excellent.
Tournament Angler and Guide Service
I have had experience personally with the lead acid battery and the AGM battery. I use lead acid in my boat and AGM batteries in my camper. Recently I had the opportunity to experience the Lithium battery technology. I was invited to fish with Joel Harris on Pickwick Lake. Joel is a crappie guide on Pickwick Lake and uses MTECH lithium batteries in his crappie guide boat.
Joel uses his trolling motor on the side of his boat to side pull for crappie. Pulling the boat sideways puts a great strain on the batteries and I noticed how strong the trolling motor stayed throughout the day. Joel told me that he runs Millertech lithium batteries. Joel never has to worry about a dead or weak battery while guiding his clients for crappie. Joel also loves the weight of his lithium batteries. A lithium battery weighs up to 30% less than lead acid. Lithium batteries are also maintenance free, and this is just one more great thing about the lithium battery, especially for the serious angler or fishing guide where every minute is precious.
Joel guides on Pickwick Lake and the wind can be brutal. Pulling the boat sideways against that wind makes lithium batteries the perfect choice. For those that rely on their batteries to run their trolling motor and electronics for their livelihood. Lithium batteries cost more upfront. However, the power and less weight make it a great choice for anyone that counts on their batteries no matter the weather. Or how long they must be on the water.
Another reason lithium batteries are a great choice for those that spend long days on the water is that lithium batteries are more depth of discharge. With lead acid and AGM, the DOD or depth of discharge should not exceed 50% for optimum lifespan. With a lithium battery DOD can be 80% to 90% without shortening its lifespan. This is a great thing when you need your power from daylight to dark or if you are boon docking in your camper.
Another reason to go with a lithium battery or batteries when choosing battery for your boat if you are a hardcore angler that needs power all day long to run all those new electronics and shallow water anchors and all the other new technologies out there is the weight savings. With the new marine electronics demanding more juice to perform properly many anglers add batteries to meet that demand.
Less Weight with Lithium Battery
The weight of additional lead acid batteries can cut into the boat’s performance. By exchanging your lead acid and/or AGM batteries with lithium batteries the weight savings add up. The addition of an extra battery or two to run your 12-inch fish finders and the steering motor on your trolling motor will not weigh you down with lithium. This lets you have more power with less weight. With lithium batteries you’ll never have to worry about running out of juice. No matter how many hours you need to find those fish.