Posted: Feb 27, 2019
How Long Will a Trolling Motor Run on a Battery?
How long will a trolling motor battery last? Are you asking about a specific day or over the life of a battery? Here are the factors that can impact both:
- How do you use the battery? If you use a trolling motor battery in windy conditions or bodies of water with strong currents, you'll probably use it more and it may not last as long as a battery used in calm water.
- How big is the battery? Generally speaking, the larger a battery is physically, the more energy it can hold. It should also be noted that the more deeply you discharge your battery, the fewer cycles you'll be able to get out of it, before it reaches the end of it's useful life. Reserve capacity, not cold cranking amps is the important specification here.
- How do you maintain the battery? Whenever batteries are discharged below 12.4 volts and are left sitting in that state, sulfation begins to form in the battery, which reduces capacity and lifespan. Fully-recharge your trolling motor battery as soon as you can after use and it will hold more energy and last longer.
- What type of battery are you using? Batteries designed and warrantied for deep-cycle use (like the OPTIMA D34M, D27M or D31M) will last longer than starting batteries that are not designed or warrantied for deep-cycle use. AGM batteries also tend to perform better and last longer than their flooded lead-acid battery counterparts and they can handle bouncing around on the back of your trailer much better than a flooded lead-acid battery.
- How thick is the wiring you are using to connect all your components?
Some may suggest a simple formula exists for determining how long a trolling motor battery will last with a specific trolling motor, but those estimates may be over-simplistic and unrealistic. Beyond the reality that a 100-lb Jon boat may be easier to move around with a trolling motor than a 28-foot deep-v hulled sport fishing boat, there are other factors to consider. Most batteries are not fully-charged when they hit the water, so expecting them to perform according to their rated specifications might be unrealistic.
Trolling motor battery performance also declines as batteries age. Battery capacity can decline and internal resistance can increase, making it harder to charge and less efficient in it's delivery of energy. OPTIMA Batteries feature cast straps to connect the cells, as opposed to the tombstone welds found in most other batteries. These thick, robust straps give you more of a firehose connection to the energy in your battery, as opposed to the partially-kinked garden hose performance you might get from a battery with tombstone welds- they'll still work, but you'll notice the difference in performance.
Regardless of what brand you choose, if you choose the largest battery (or batteries) you can find, make sure it is designed for deep-cycle use and keep them fully-charged whenever possible for better-performing, longer-lasting trolling motor batteries